--- a/hotspot/make/hotspot_version Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/make/hotspot_version Fri Dec 02 15:11:18 2011 -0800
@@ -35,7 +35,7 @@
HS_MAJOR_VER=23
HS_MINOR_VER=0
-HS_BUILD_NUMBER=06
+HS_BUILD_NUMBER=07
JDK_MAJOR_VER=1
JDK_MINOR_VER=8
--- a/hotspot/make/linux/makefiles/mapfile-vers-debug Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/make/linux/makefiles/mapfile-vers-debug Fri Dec 02 15:11:18 2011 -0800
@@ -1,7 +1,3 @@
-#
-# @(#)mapfile-vers-debug 1.18 07/10/25 16:47:35
-#
-
#
# Copyright (c) 2002, 2011, Oracle and/or its affiliates. All rights reserved.
# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -221,6 +217,7 @@
JVM_SetArrayElement;
JVM_SetClassSigners;
JVM_SetLength;
+ JVM_SetNativeThreadName;
JVM_SetPrimitiveArrayElement;
JVM_SetProtectionDomain;
JVM_SetSockOpt;
--- a/hotspot/make/linux/makefiles/mapfile-vers-product Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/make/linux/makefiles/mapfile-vers-product Fri Dec 02 15:11:18 2011 -0800
@@ -1,7 +1,3 @@
-#
-# @(#)mapfile-vers-product 1.19 08/02/12 10:56:37
-#
-
#
# Copyright (c) 2002, 2011, Oracle and/or its affiliates. All rights reserved.
# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -221,6 +217,7 @@
JVM_SetArrayElement;
JVM_SetClassSigners;
JVM_SetLength;
+ JVM_SetNativeThreadName;
JVM_SetPrimitiveArrayElement;
JVM_SetProtectionDomain;
JVM_SetSockOpt;
--- a/hotspot/make/solaris/makefiles/mapfile-vers Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/make/solaris/makefiles/mapfile-vers Fri Dec 02 15:11:18 2011 -0800
@@ -1,7 +1,3 @@
-#
-# @(#)mapfile-vers 1.32 07/10/25 16:47:36
-#
-
#
# Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -221,6 +217,7 @@
JVM_SetArrayElement;
JVM_SetClassSigners;
JVM_SetLength;
+ JVM_SetNativeThreadName;
JVM_SetPrimitiveArrayElement;
JVM_SetProtectionDomain;
JVM_SetSockOpt;
--- a/hotspot/make/windows/makefiles/projectcreator.make Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/make/windows/makefiles/projectcreator.make Fri Dec 02 15:11:18 2011 -0800
@@ -50,6 +50,7 @@
-relativeInclude src\closed\os_cpu\windows_$(Platform_arch)\vm \
-relativeInclude src\closed\cpu\$(Platform_arch)\vm \
-relativeInclude src\share\vm \
+ -relativeInclude src\share\vm\precompiled \
-relativeInclude src\share\vm\prims \
-relativeInclude src\os\windows\vm \
-relativeInclude src\os_cpu\windows_$(Platform_arch)\vm \
--- a/hotspot/src/os/bsd/vm/os_bsd.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/os/bsd/vm/os_bsd.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -5778,15 +5778,18 @@
// is_headless_jre()
//
-// Test for the existence of libmawt in motif21 or xawt directories
+// Test for the existence of xawt/libmawt.so or libawt_xawt.so
// in order to report if we are running in a headless jre
//
+// Since JDK8 xawt/libmawt.so was moved into the same directory
+// as libawt.so, and renamed libawt_xawt.so
+//
bool os::is_headless_jre() {
struct stat statbuf;
char buf[MAXPATHLEN];
char libmawtpath[MAXPATHLEN];
const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX;
- const char *motifstr = "/motif21/libmawt" JNI_LIB_SUFFIX;
+ const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
char *p;
// Get path to libjvm.so
@@ -5807,9 +5810,9 @@
strcat(libmawtpath, xawtstr);
if (::stat(libmawtpath, &statbuf) == 0) return false;
- // check motif21/libmawt.so
+ // check libawt_xawt.so
strcpy(libmawtpath, buf);
- strcat(libmawtpath, motifstr);
+ strcat(libmawtpath, new_xawtstr);
if (::stat(libmawtpath, &statbuf) == 0) return false;
return true;
--- a/hotspot/src/os/linux/vm/os_linux.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/os/linux/vm/os_linux.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -5425,15 +5425,18 @@
// is_headless_jre()
//
-// Test for the existence of libmawt in motif21 or xawt directories
+// Test for the existence of xawt/libmawt.so or libawt_xawt.so
// in order to report if we are running in a headless jre
//
+// Since JDK8 xawt/libmawt.so was moved into the same directory
+// as libawt.so, and renamed libawt_xawt.so
+//
bool os::is_headless_jre() {
struct stat statbuf;
char buf[MAXPATHLEN];
char libmawtpath[MAXPATHLEN];
const char *xawtstr = "/xawt/libmawt.so";
- const char *motifstr = "/motif21/libmawt.so";
+ const char *new_xawtstr = "/libawt_xawt.so";
char *p;
// Get path to libjvm.so
@@ -5454,9 +5457,9 @@
strcat(libmawtpath, xawtstr);
if (::stat(libmawtpath, &statbuf) == 0) return false;
- // check motif21/libmawt.so
+ // check libawt_xawt.so
strcpy(libmawtpath, buf);
- strcat(libmawtpath, motifstr);
+ strcat(libmawtpath, new_xawtstr);
if (::stat(libmawtpath, &statbuf) == 0) return false;
return true;
--- a/hotspot/src/os/solaris/vm/os_solaris.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/os/solaris/vm/os_solaris.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -6311,15 +6311,18 @@
// is_headless_jre()
//
-// Test for the existence of libmawt in motif21 or xawt directories
+// Test for the existence of xawt/libmawt.so or libawt_xawt.so
// in order to report if we are running in a headless jre
//
+// Since JDK8 xawt/libmawt.so was moved into the same directory
+// as libawt.so, and renamed libawt_xawt.so
+//
bool os::is_headless_jre() {
struct stat statbuf;
char buf[MAXPATHLEN];
char libmawtpath[MAXPATHLEN];
const char *xawtstr = "/xawt/libmawt.so";
- const char *motifstr = "/motif21/libmawt.so";
+ const char *new_xawtstr = "/libawt_xawt.so";
char *p;
// Get path to libjvm.so
@@ -6340,9 +6343,9 @@
strcat(libmawtpath, xawtstr);
if (::stat(libmawtpath, &statbuf) == 0) return false;
- // check motif21/libmawt.so
+ // check libawt_xawt.so
strcpy(libmawtpath, buf);
- strcat(libmawtpath, motifstr);
+ strcat(libmawtpath, new_xawtstr);
if (::stat(libmawtpath, &statbuf) == 0) return false;
return true;
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -668,12 +668,16 @@
// We de-virtualize the block-related calls below, since we know that our
// space is a CompactibleFreeListSpace.
+
#define FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(ClosureType) \
void FreeListSpace_DCTOC::walk_mem_region_with_cl(MemRegion mr, \
HeapWord* bottom, \
HeapWord* top, \
ClosureType* cl) { \
- if (SharedHeap::heap()->n_par_threads() > 0) { \
+ bool is_par = SharedHeap::heap()->n_par_threads() > 0; \
+ if (is_par) { \
+ assert(SharedHeap::heap()->n_par_threads() == \
+ SharedHeap::heap()->workers()->active_workers(), "Mismatch"); \
walk_mem_region_with_cl_par(mr, bottom, top, cl); \
} else { \
walk_mem_region_with_cl_nopar(mr, bottom, top, cl); \
@@ -1925,6 +1929,9 @@
if (rem_size < SmallForDictionary) {
bool is_par = (SharedHeap::heap()->n_par_threads() > 0);
if (is_par) _indexedFreeListParLocks[rem_size]->lock();
+ assert(!is_par ||
+ (SharedHeap::heap()->n_par_threads() ==
+ SharedHeap::heap()->workers()->active_workers()), "Mismatch");
returnChunkToFreeList(ffc);
split(size, rem_size);
if (is_par) _indexedFreeListParLocks[rem_size]->unlock();
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -3582,16 +3582,6 @@
" or no bits are set in the gc_prologue before the start of the next "
"subsequent marking phase.");
- // Temporarily disabled, since pre/post-consumption closures don't
- // care about precleaned cards
- #if 0
- {
- MemRegion mr = MemRegion((HeapWord*)_virtual_space.low(),
- (HeapWord*)_virtual_space.high());
- _ct->ct_bs()->preclean_dirty_cards(mr);
- }
- #endif
-
// Save the end of the used_region of the constituent generations
// to be used to limit the extent of sweep in each generation.
save_sweep_limits();
@@ -4244,9 +4234,11 @@
bool CMSCollector::do_marking_mt(bool asynch) {
assert(ConcGCThreads > 0 && conc_workers() != NULL, "precondition");
- // In the future this would be determined ergonomically, based
- // on #cpu's, # active mutator threads (and load), and mutation rate.
- int num_workers = ConcGCThreads;
+ int num_workers = AdaptiveSizePolicy::calc_active_conc_workers(
+ conc_workers()->total_workers(),
+ conc_workers()->active_workers(),
+ Threads::number_of_non_daemon_threads());
+ conc_workers()->set_active_workers(num_workers);
CompactibleFreeListSpace* cms_space = _cmsGen->cmsSpace();
CompactibleFreeListSpace* perm_space = _permGen->cmsSpace();
@@ -5062,6 +5054,8 @@
ParallelTaskTerminator _term;
public:
+ // A value of 0 passed to n_workers will cause the number of
+ // workers to be taken from the active workers in the work gang.
CMSParRemarkTask(CMSCollector* collector,
CompactibleFreeListSpace* cms_space,
CompactibleFreeListSpace* perm_space,
@@ -5544,7 +5538,15 @@
GenCollectedHeap* gch = GenCollectedHeap::heap();
FlexibleWorkGang* workers = gch->workers();
assert(workers != NULL, "Need parallel worker threads.");
- int n_workers = workers->total_workers();
+ // Choose to use the number of GC workers most recently set
+ // into "active_workers". If active_workers is not set, set it
+ // to ParallelGCThreads.
+ int n_workers = workers->active_workers();
+ if (n_workers == 0) {
+ assert(n_workers > 0, "Should have been set during scavenge");
+ n_workers = ParallelGCThreads;
+ workers->set_active_workers(n_workers);
+ }
CompactibleFreeListSpace* cms_space = _cmsGen->cmsSpace();
CompactibleFreeListSpace* perm_space = _permGen->cmsSpace();
@@ -5884,8 +5886,17 @@
// and a different number of discovered lists may have Ref objects.
// That is OK as long as the Reference lists are balanced (see
// balance_all_queues() and balance_queues()).
-
- rp->set_active_mt_degree(ParallelGCThreads);
+ GenCollectedHeap* gch = GenCollectedHeap::heap();
+ int active_workers = ParallelGCThreads;
+ FlexibleWorkGang* workers = gch->workers();
+ if (workers != NULL) {
+ active_workers = workers->active_workers();
+ // The expectation is that active_workers will have already
+ // been set to a reasonable value. If it has not been set,
+ // investigate.
+ assert(active_workers > 0, "Should have been set during scavenge");
+ }
+ rp->set_active_mt_degree(active_workers);
CMSRefProcTaskExecutor task_executor(*this);
rp->process_discovered_references(&_is_alive_closure,
&cmsKeepAliveClosure,
--- a/hotspot/src/share/vm/gc_implementation/g1/collectionSetChooser.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/collectionSetChooser.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -255,7 +255,18 @@
CollectionSetChooser::
prepareForAddMarkedHeapRegionsPar(size_t n_regions, size_t chunkSize) {
_first_par_unreserved_idx = 0;
- size_t max_waste = ParallelGCThreads * chunkSize;
+ int n_threads = ParallelGCThreads;
+ if (UseDynamicNumberOfGCThreads) {
+ assert(G1CollectedHeap::heap()->workers()->active_workers() > 0,
+ "Should have been set earlier");
+ // This is defensive code. As the assertion above says, the number
+ // of active threads should be > 0, but in case there is some path
+ // or some improperly initialized variable with leads to no
+ // active threads, protect against that in a product build.
+ n_threads = MAX2(G1CollectedHeap::heap()->workers()->active_workers(),
+ 1);
+ }
+ size_t max_waste = n_threads * chunkSize;
// it should be aligned with respect to chunkSize
size_t aligned_n_regions =
(n_regions + (chunkSize - 1)) / chunkSize * chunkSize;
@@ -265,6 +276,11 @@
jint
CollectionSetChooser::getParMarkedHeapRegionChunk(jint n_regions) {
+ // Don't do this assert because this can be called at a point
+ // where the loop up stream will not execute again but might
+ // try to claim more chunks (loop test has not been done yet).
+ // assert(_markedRegions.length() > _first_par_unreserved_idx,
+ // "Striding beyond the marked regions");
jint res = Atomic::add(n_regions, &_first_par_unreserved_idx);
assert(_markedRegions.length() > res + n_regions - 1,
"Should already have been expanded");
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -44,7 +44,7 @@
//
// CMS Bit Map Wrapper
-CMBitMapRO::CMBitMapRO(ReservedSpace rs, int shifter):
+CMBitMapRO::CMBitMapRO(ReservedSpace rs, int shifter) :
_bm((uintptr_t*)NULL,0),
_shifter(shifter) {
_bmStartWord = (HeapWord*)(rs.base());
@@ -458,12 +458,17 @@
#pragma warning( disable:4355 ) // 'this' : used in base member initializer list
#endif // _MSC_VER
+size_t ConcurrentMark::scale_parallel_threads(size_t n_par_threads) {
+ return MAX2((n_par_threads + 2) / 4, (size_t)1);
+}
+
ConcurrentMark::ConcurrentMark(ReservedSpace rs,
int max_regions) :
_markBitMap1(rs, MinObjAlignment - 1),
_markBitMap2(rs, MinObjAlignment - 1),
_parallel_marking_threads(0),
+ _max_parallel_marking_threads(0),
_sleep_factor(0.0),
_marking_task_overhead(1.0),
_cleanup_sleep_factor(0.0),
@@ -554,15 +559,17 @@
if (ParallelGCThreads == 0) {
// if we are not running with any parallel GC threads we will not
// spawn any marking threads either
- _parallel_marking_threads = 0;
- _sleep_factor = 0.0;
- _marking_task_overhead = 1.0;
+ _parallel_marking_threads = 0;
+ _max_parallel_marking_threads = 0;
+ _sleep_factor = 0.0;
+ _marking_task_overhead = 1.0;
} else {
if (ConcGCThreads > 0) {
// notice that ConcGCThreads overwrites G1MarkingOverheadPercent
// if both are set
_parallel_marking_threads = ConcGCThreads;
+ _max_parallel_marking_threads = _parallel_marking_threads;
_sleep_factor = 0.0;
_marking_task_overhead = 1.0;
} else if (G1MarkingOverheadPercent > 0) {
@@ -583,10 +590,12 @@
(1.0 - marking_task_overhead) / marking_task_overhead;
_parallel_marking_threads = (size_t) marking_thread_num;
+ _max_parallel_marking_threads = _parallel_marking_threads;
_sleep_factor = sleep_factor;
_marking_task_overhead = marking_task_overhead;
} else {
- _parallel_marking_threads = MAX2((ParallelGCThreads + 2) / 4, (size_t)1);
+ _parallel_marking_threads = scale_parallel_threads(ParallelGCThreads);
+ _max_parallel_marking_threads = _parallel_marking_threads;
_sleep_factor = 0.0;
_marking_task_overhead = 1.0;
}
@@ -609,7 +618,7 @@
guarantee(parallel_marking_threads() > 0, "peace of mind");
_parallel_workers = new FlexibleWorkGang("G1 Parallel Marking Threads",
- (int) _parallel_marking_threads, false, true);
+ (int) _max_parallel_marking_threads, false, true);
if (_parallel_workers == NULL) {
vm_exit_during_initialization("Failed necessary allocation.");
} else {
@@ -1106,6 +1115,33 @@
~CMConcurrentMarkingTask() { }
};
+// Calculates the number of active workers for a concurrent
+// phase.
+int ConcurrentMark::calc_parallel_marking_threads() {
+
+ size_t n_conc_workers;
+ if (!G1CollectedHeap::use_parallel_gc_threads()) {
+ n_conc_workers = 1;
+ } else {
+ if (!UseDynamicNumberOfGCThreads ||
+ (!FLAG_IS_DEFAULT(ConcGCThreads) &&
+ !ForceDynamicNumberOfGCThreads)) {
+ n_conc_workers = max_parallel_marking_threads();
+ } else {
+ n_conc_workers =
+ AdaptiveSizePolicy::calc_default_active_workers(
+ max_parallel_marking_threads(),
+ 1, /* Minimum workers */
+ parallel_marking_threads(),
+ Threads::number_of_non_daemon_threads());
+ // Don't scale down "n_conc_workers" by scale_parallel_threads() because
+ // that scaling has already gone into "_max_parallel_marking_threads".
+ }
+ }
+ assert(n_conc_workers > 0, "Always need at least 1");
+ return (int) MAX2(n_conc_workers, (size_t) 1);
+}
+
void ConcurrentMark::markFromRoots() {
// we might be tempted to assert that:
// assert(asynch == !SafepointSynchronize::is_at_safepoint(),
@@ -1116,9 +1152,20 @@
_restart_for_overflow = false;
- size_t active_workers = MAX2((size_t) 1, parallel_marking_threads());
+ // Parallel task terminator is set in "set_phase()".
force_overflow_conc()->init();
- set_phase(active_workers, true /* concurrent */);
+
+ // _g1h has _n_par_threads
+
+ _parallel_marking_threads = calc_parallel_marking_threads();
+ assert(parallel_marking_threads() <= max_parallel_marking_threads(),
+ "Maximum number of marking threads exceeded");
+ _parallel_workers->set_active_workers((int)_parallel_marking_threads);
+ // Don't set _n_par_threads because it affects MT in proceess_strong_roots()
+ // and the decisions on that MT processing is made elsewhere.
+
+ assert( _parallel_workers->active_workers() > 0, "Should have been set");
+ set_phase(_parallel_workers->active_workers(), true /* concurrent */);
CMConcurrentMarkingTask markingTask(this, cmThread());
if (parallel_marking_threads() > 0) {
@@ -1181,6 +1228,7 @@
true /* expected_active */);
if (VerifyDuringGC) {
+
HandleMark hm; // handle scope
gclog_or_tty->print(" VerifyDuringGC:(after)");
Universe::heap()->prepare_for_verify();
@@ -1463,12 +1511,20 @@
G1ParFinalCountTask(G1CollectedHeap* g1h, CMBitMap* bm,
BitMap* region_bm, BitMap* card_bm)
: AbstractGangTask("G1 final counting"), _g1h(g1h),
- _bm(bm), _region_bm(region_bm), _card_bm(card_bm) {
- if (ParallelGCThreads > 0) {
- _n_workers = _g1h->workers()->total_workers();
+ _bm(bm), _region_bm(region_bm), _card_bm(card_bm),
+ _n_workers(0)
+ {
+ // Use the value already set as the number of active threads
+ // in the call to run_task(). Needed for the allocation of
+ // _live_bytes and _used_bytes.
+ if (G1CollectedHeap::use_parallel_gc_threads()) {
+ assert( _g1h->workers()->active_workers() > 0,
+ "Should have been previously set");
+ _n_workers = _g1h->workers()->active_workers();
} else {
_n_workers = 1;
}
+
_live_bytes = NEW_C_HEAP_ARRAY(size_t, _n_workers);
_used_bytes = NEW_C_HEAP_ARRAY(size_t, _n_workers);
}
@@ -1485,6 +1541,7 @@
calccl.no_yield();
if (G1CollectedHeap::use_parallel_gc_threads()) {
_g1h->heap_region_par_iterate_chunked(&calccl, i,
+ (int) _n_workers,
HeapRegion::FinalCountClaimValue);
} else {
_g1h->heap_region_iterate(&calccl);
@@ -1530,10 +1587,42 @@
FreeRegionList* local_cleanup_list,
OldRegionSet* old_proxy_set,
HumongousRegionSet* humongous_proxy_set,
- HRRSCleanupTask* hrrs_cleanup_task);
+ HRRSCleanupTask* hrrs_cleanup_task) :
+ _g1(g1), _worker_num(worker_num),
+ _max_live_bytes(0), _regions_claimed(0),
+ _freed_bytes(0),
+ _claimed_region_time(0.0), _max_region_time(0.0),
+ _local_cleanup_list(local_cleanup_list),
+ _old_proxy_set(old_proxy_set),
+ _humongous_proxy_set(humongous_proxy_set),
+ _hrrs_cleanup_task(hrrs_cleanup_task) { }
+
size_t freed_bytes() { return _freed_bytes; }
- bool doHeapRegion(HeapRegion *r);
+ bool doHeapRegion(HeapRegion *hr) {
+ // We use a claim value of zero here because all regions
+ // were claimed with value 1 in the FinalCount task.
+ hr->reset_gc_time_stamp();
+ if (!hr->continuesHumongous()) {
+ double start = os::elapsedTime();
+ _regions_claimed++;
+ hr->note_end_of_marking();
+ _max_live_bytes += hr->max_live_bytes();
+ _g1->free_region_if_empty(hr,
+ &_freed_bytes,
+ _local_cleanup_list,
+ _old_proxy_set,
+ _humongous_proxy_set,
+ _hrrs_cleanup_task,
+ true /* par */);
+ double region_time = (os::elapsedTime() - start);
+ _claimed_region_time += region_time;
+ if (region_time > _max_region_time) {
+ _max_region_time = region_time;
+ }
+ }
+ return false;
+ }
size_t max_live_bytes() { return _max_live_bytes; }
size_t regions_claimed() { return _regions_claimed; }
@@ -1568,6 +1657,7 @@
&hrrs_cleanup_task);
if (G1CollectedHeap::use_parallel_gc_threads()) {
_g1h->heap_region_par_iterate_chunked(&g1_note_end, i,
+ _g1h->workers()->active_workers(),
HeapRegion::NoteEndClaimValue);
} else {
_g1h->heap_region_iterate(&g1_note_end);
@@ -1644,47 +1734,6 @@
};
-G1NoteEndOfConcMarkClosure::
-G1NoteEndOfConcMarkClosure(G1CollectedHeap* g1,
- int worker_num,
- FreeRegionList* local_cleanup_list,
- OldRegionSet* old_proxy_set,
- HumongousRegionSet* humongous_proxy_set,
- HRRSCleanupTask* hrrs_cleanup_task)
- : _g1(g1), _worker_num(worker_num),
- _max_live_bytes(0), _regions_claimed(0),
- _freed_bytes(0),
- _claimed_region_time(0.0), _max_region_time(0.0),
- _local_cleanup_list(local_cleanup_list),
- _old_proxy_set(old_proxy_set),
- _humongous_proxy_set(humongous_proxy_set),
- _hrrs_cleanup_task(hrrs_cleanup_task) { }
-
-bool G1NoteEndOfConcMarkClosure::doHeapRegion(HeapRegion *hr) {
- // We use a claim value of zero here because all regions
- // were claimed with value 1 in the FinalCount task.
- hr->reset_gc_time_stamp();
- if (!hr->continuesHumongous()) {
- double start = os::elapsedTime();
- _regions_claimed++;
- hr->note_end_of_marking();
- _max_live_bytes += hr->max_live_bytes();
- _g1->free_region_if_empty(hr,
- &_freed_bytes,
- _local_cleanup_list,
- _old_proxy_set,
- _humongous_proxy_set,
- _hrrs_cleanup_task,
- true /* par */);
- double region_time = (os::elapsedTime() - start);
- _claimed_region_time += region_time;
- if (region_time > _max_region_time) {
- _max_region_time = region_time;
- }
- }
- return false;
-}
-
void ConcurrentMark::cleanup() {
// world is stopped at this checkpoint
assert(SafepointSynchronize::is_at_safepoint(),
@@ -1716,6 +1765,9 @@
HeapRegionRemSet::reset_for_cleanup_tasks();
+ g1h->set_par_threads();
+ size_t n_workers = g1h->n_par_threads();
+
// Do counting once more with the world stopped for good measure.
G1ParFinalCountTask g1_par_count_task(g1h, nextMarkBitMap(),
&_region_bm, &_card_bm);
@@ -1724,9 +1776,10 @@
HeapRegion::InitialClaimValue),
"sanity check");
- int n_workers = g1h->workers()->total_workers();
- g1h->set_par_threads(n_workers);
+ assert(g1h->n_par_threads() == (int) n_workers,
+ "Should not have been reset");
g1h->workers()->run_task(&g1_par_count_task);
+ // Done with the parallel phase so reset to 0.
g1h->set_par_threads(0);
assert(g1h->check_heap_region_claim_values(
@@ -1776,8 +1829,7 @@
double note_end_start = os::elapsedTime();
G1ParNoteEndTask g1_par_note_end_task(g1h, &_cleanup_list);
if (G1CollectedHeap::use_parallel_gc_threads()) {
- int n_workers = g1h->workers()->total_workers();
- g1h->set_par_threads(n_workers);
+ g1h->set_par_threads((int)n_workers);
g1h->workers()->run_task(&g1_par_note_end_task);
g1h->set_par_threads(0);
@@ -1806,8 +1858,7 @@
double rs_scrub_start = os::elapsedTime();
G1ParScrubRemSetTask g1_par_scrub_rs_task(g1h, &_region_bm, &_card_bm);
if (G1CollectedHeap::use_parallel_gc_threads()) {
- int n_workers = g1h->workers()->total_workers();
- g1h->set_par_threads(n_workers);
+ g1h->set_par_threads((int)n_workers);
g1h->workers()->run_task(&g1_par_scrub_rs_task);
g1h->set_par_threads(0);
@@ -1825,7 +1876,7 @@
// this will also free any regions totally full of garbage objects,
// and sort the regions.
- g1h->g1_policy()->record_concurrent_mark_cleanup_end();
+ g1h->g1_policy()->record_concurrent_mark_cleanup_end((int)n_workers);
// Statistics.
double end = os::elapsedTime();
@@ -1991,16 +2042,12 @@
class G1CMParKeepAliveAndDrainClosure: public OopClosure {
ConcurrentMark* _cm;
CMTask* _task;
- CMBitMap* _bitMap;
int _ref_counter_limit;
int _ref_counter;
public:
- G1CMParKeepAliveAndDrainClosure(ConcurrentMark* cm,
- CMTask* task,
- CMBitMap* bitMap) :
- _cm(cm), _task(task), _bitMap(bitMap),
- _ref_counter_limit(G1RefProcDrainInterval)
- {
+ G1CMParKeepAliveAndDrainClosure(ConcurrentMark* cm, CMTask* task) :
+ _cm(cm), _task(task),
+ _ref_counter_limit(G1RefProcDrainInterval) {
assert(_ref_counter_limit > 0, "sanity");
_ref_counter = _ref_counter_limit;
}
@@ -2091,19 +2138,16 @@
private:
G1CollectedHeap* _g1h;
ConcurrentMark* _cm;
- CMBitMap* _bitmap;
WorkGang* _workers;
int _active_workers;
public:
G1CMRefProcTaskExecutor(G1CollectedHeap* g1h,
ConcurrentMark* cm,
- CMBitMap* bitmap,
WorkGang* workers,
int n_workers) :
- _g1h(g1h), _cm(cm), _bitmap(bitmap),
- _workers(workers), _active_workers(n_workers)
- { }
+ _g1h(g1h), _cm(cm),
+ _workers(workers), _active_workers(n_workers) { }
// Executes the given task using concurrent marking worker threads.
virtual void execute(ProcessTask& task);
@@ -2115,21 +2159,18 @@
ProcessTask& _proc_task;
G1CollectedHeap* _g1h;
ConcurrentMark* _cm;
- CMBitMap* _bitmap;
public:
G1CMRefProcTaskProxy(ProcessTask& proc_task,
G1CollectedHeap* g1h,
- ConcurrentMark* cm,
- CMBitMap* bitmap) :
+ ConcurrentMark* cm) :
AbstractGangTask("Process reference objects in parallel"),
- _proc_task(proc_task), _g1h(g1h), _cm(cm), _bitmap(bitmap)
- {}
+ _proc_task(proc_task), _g1h(g1h), _cm(cm) { }
virtual void work(int i) {
CMTask* marking_task = _cm->task(i);
G1CMIsAliveClosure g1_is_alive(_g1h);
- G1CMParKeepAliveAndDrainClosure g1_par_keep_alive(_cm, marking_task, _bitmap);
+ G1CMParKeepAliveAndDrainClosure g1_par_keep_alive(_cm, marking_task);
G1CMParDrainMarkingStackClosure g1_par_drain(_cm, marking_task);
_proc_task.work(i, g1_is_alive, g1_par_keep_alive, g1_par_drain);
@@ -2139,7 +2180,7 @@
void G1CMRefProcTaskExecutor::execute(ProcessTask& proc_task) {
assert(_workers != NULL, "Need parallel worker threads.");
- G1CMRefProcTaskProxy proc_task_proxy(proc_task, _g1h, _cm, _bitmap);
+ G1CMRefProcTaskProxy proc_task_proxy(proc_task, _g1h, _cm);
// We need to reset the phase for each task execution so that
// the termination protocol of CMTask::do_marking_step works.
@@ -2156,8 +2197,7 @@
public:
G1CMRefEnqueueTaskProxy(EnqueueTask& enq_task) :
AbstractGangTask("Enqueue reference objects in parallel"),
- _enq_task(enq_task)
- { }
+ _enq_task(enq_task) { }
virtual void work(int i) {
_enq_task.work(i);
@@ -2207,10 +2247,10 @@
// We use the work gang from the G1CollectedHeap and we utilize all
// the worker threads.
- int active_workers = g1h->workers() ? g1h->workers()->total_workers() : 1;
+ int active_workers = g1h->workers() ? g1h->workers()->active_workers() : 1;
active_workers = MAX2(MIN2(active_workers, (int)_max_task_num), 1);
- G1CMRefProcTaskExecutor par_task_executor(g1h, this, nextMarkBitMap(),
+ G1CMRefProcTaskExecutor par_task_executor(g1h, this,
g1h->workers(), active_workers);
if (rp->processing_is_mt()) {
@@ -2290,7 +2330,9 @@
}
CMRemarkTask(ConcurrentMark* cm) :
- AbstractGangTask("Par Remark"), _cm(cm) { }
+ AbstractGangTask("Par Remark"), _cm(cm) {
+ _cm->terminator()->reset_for_reuse(cm->_g1h->workers()->active_workers());
+ }
};
void ConcurrentMark::checkpointRootsFinalWork() {
@@ -2302,16 +2344,21 @@
if (G1CollectedHeap::use_parallel_gc_threads()) {
G1CollectedHeap::StrongRootsScope srs(g1h);
- // this is remark, so we'll use up all available threads
- int active_workers = ParallelGCThreads;
+ // this is remark, so we'll use up all active threads
+ int active_workers = g1h->workers()->active_workers();
+ if (active_workers == 0) {
+ assert(active_workers > 0, "Should have been set earlier");
+ active_workers = ParallelGCThreads;
+ g1h->workers()->set_active_workers(active_workers);
+ }
set_phase(active_workers, false /* concurrent */);
+ // Leave _parallel_marking_threads at it's
+ // value originally calculated in the ConcurrentMark
+ // constructor and pass values of the active workers
+ // through the gang in the task.
CMRemarkTask remarkTask(this);
- // We will start all available threads, even if we decide that the
- // active_workers will be fewer. The extra ones will just bail out
- // immediately.
- int n_workers = g1h->workers()->total_workers();
- g1h->set_par_threads(n_workers);
+ g1h->set_par_threads(active_workers);
g1h->workers()->run_task(&remarkTask);
g1h->set_par_threads(0);
} else {
@@ -2859,8 +2906,10 @@
}
}
-class CSMarkOopClosure: public OopClosure {
- friend class CSMarkBitMapClosure;
+// Closures used by ConcurrentMark::complete_marking_in_collection_set().
+
+class CSetMarkOopClosure: public OopClosure {
+ friend class CSetMarkBitMapClosure;
G1CollectedHeap* _g1h;
CMBitMap* _bm;
@@ -2870,6 +2919,7 @@
int _ms_size;
int _ms_ind;
int _array_increment;
+ int _worker_i;
bool push(oop obj, int arr_ind = 0) {
if (_ms_ind == _ms_size) {
@@ -2910,7 +2960,6 @@
for (int j = arr_ind; j < lim; j++) {
do_oop(aobj->objArrayOopDesc::obj_at_addr<T>(j));
}
-
} else {
obj->oop_iterate(this);
}
@@ -2920,17 +2969,17 @@
}
public:
- CSMarkOopClosure(ConcurrentMark* cm, int ms_size) :
+ CSetMarkOopClosure(ConcurrentMark* cm, int ms_size, int worker_i) :
_g1h(G1CollectedHeap::heap()),
_cm(cm),
_bm(cm->nextMarkBitMap()),
_ms_size(ms_size), _ms_ind(0),
_ms(NEW_C_HEAP_ARRAY(oop, ms_size)),
_array_ind_stack(NEW_C_HEAP_ARRAY(jint, ms_size)),
- _array_increment(MAX2(ms_size/8, 16))
- {}
-
- ~CSMarkOopClosure() {
+ _array_increment(MAX2(ms_size/8, 16)),
+ _worker_i(worker_i) { }
+
+ ~CSetMarkOopClosure() {
FREE_C_HEAP_ARRAY(oop, _ms);
FREE_C_HEAP_ARRAY(jint, _array_ind_stack);
}
@@ -2953,10 +3002,11 @@
if (hr != NULL) {
if (hr->in_collection_set()) {
if (_g1h->is_obj_ill(obj)) {
- _bm->mark((HeapWord*)obj);
- if (!push(obj)) {
- gclog_or_tty->print_cr("Setting abort in CSMarkOopClosure because push failed.");
- set_abort();
+ if (_bm->parMark((HeapWord*)obj)) {
+ if (!push(obj)) {
+ gclog_or_tty->print_cr("Setting abort in CSetMarkOopClosure because push failed.");
+ set_abort();
+ }
}
}
} else {
@@ -2967,19 +3017,19 @@
}
};
-class CSMarkBitMapClosure: public BitMapClosure {
- G1CollectedHeap* _g1h;
- CMBitMap* _bitMap;
- ConcurrentMark* _cm;
- CSMarkOopClosure _oop_cl;
+class CSetMarkBitMapClosure: public BitMapClosure {
+ G1CollectedHeap* _g1h;
+ CMBitMap* _bitMap;
+ ConcurrentMark* _cm;
+ CSetMarkOopClosure _oop_cl;
+ int _worker_i;
+
public:
- CSMarkBitMapClosure(ConcurrentMark* cm, int ms_size) :
+ CSetMarkBitMapClosure(ConcurrentMark* cm, int ms_size, int worker_i) :
_g1h(G1CollectedHeap::heap()),
_bitMap(cm->nextMarkBitMap()),
- _oop_cl(cm, ms_size)
- {}
-
- ~CSMarkBitMapClosure() {}
+ _oop_cl(cm, ms_size, worker_i),
+ _worker_i(worker_i) { }
bool do_bit(size_t offset) {
// convert offset into a HeapWord*
@@ -3001,53 +3051,69 @@
}
};
-
-class CompleteMarkingInCSHRClosure: public HeapRegionClosure {
- CMBitMap* _bm;
- CSMarkBitMapClosure _bit_cl;
+class CompleteMarkingInCSetHRClosure: public HeapRegionClosure {
+ CMBitMap* _bm;
+ CSetMarkBitMapClosure _bit_cl;
+ int _worker_i;
+
enum SomePrivateConstants {
MSSize = 1000
};
- bool _completed;
+
public:
- CompleteMarkingInCSHRClosure(ConcurrentMark* cm) :
+ CompleteMarkingInCSetHRClosure(ConcurrentMark* cm, int worker_i) :
_bm(cm->nextMarkBitMap()),
- _bit_cl(cm, MSSize),
- _completed(true)
- {}
-
- ~CompleteMarkingInCSHRClosure() {}
-
- bool doHeapRegion(HeapRegion* r) {
- if (!r->evacuation_failed()) {
- MemRegion mr = MemRegion(r->bottom(), r->next_top_at_mark_start());
- if (!mr.is_empty()) {
- if (!_bm->iterate(&_bit_cl, mr)) {
- _completed = false;
- return true;
+ _bit_cl(cm, MSSize, worker_i),
+ _worker_i(worker_i) { }
+
+ bool doHeapRegion(HeapRegion* hr) {
+ if (hr->claimHeapRegion(HeapRegion::CompleteMarkCSetClaimValue)) {
+ // The current worker has successfully claimed the region.
+ if (!hr->evacuation_failed()) {
+ MemRegion mr = MemRegion(hr->bottom(), hr->next_top_at_mark_start());
+ if (!mr.is_empty()) {
+ bool done = false;
+ while (!done) {
+ done = _bm->iterate(&_bit_cl, mr);
+ }
}
}
}
return false;
}
-
- bool completed() { return _completed; }
};
-class ClearMarksInHRClosure: public HeapRegionClosure {
- CMBitMap* _bm;
+class SetClaimValuesInCSetHRClosure: public HeapRegionClosure {
+ jint _claim_value;
+
public:
- ClearMarksInHRClosure(CMBitMap* bm): _bm(bm) { }
-
- bool doHeapRegion(HeapRegion* r) {
- if (!r->used_region().is_empty() && !r->evacuation_failed()) {
- MemRegion usedMR = r->used_region();
- _bm->clearRange(r->used_region());
- }
+ SetClaimValuesInCSetHRClosure(jint claim_value) :
+ _claim_value(claim_value) { }
+
+ bool doHeapRegion(HeapRegion* hr) {
+ hr->set_claim_value(_claim_value);
return false;
}
};
+class G1ParCompleteMarkInCSetTask: public AbstractGangTask {
+protected:
+ G1CollectedHeap* _g1h;
+ ConcurrentMark* _cm;
+
+public:
+ G1ParCompleteMarkInCSetTask(G1CollectedHeap* g1h,
+ ConcurrentMark* cm) :
+ AbstractGangTask("Complete Mark in CSet"),
+ _g1h(g1h), _cm(cm) { }
+
+ void work(int worker_i) {
+ CompleteMarkingInCSetHRClosure cmplt(_cm, worker_i);
+ HeapRegion* hr = _g1h->start_cset_region_for_worker(worker_i);
+ _g1h->collection_set_iterate_from(hr, &cmplt);
+ }
+};
+
void ConcurrentMark::complete_marking_in_collection_set() {
G1CollectedHeap* g1h = G1CollectedHeap::heap();
@@ -3056,20 +3122,32 @@
return;
}
- int i = 1;
double start = os::elapsedTime();
- while (true) {
- i++;
- CompleteMarkingInCSHRClosure cmplt(this);
- g1h->collection_set_iterate(&cmplt);
- if (cmplt.completed()) break;
+ int n_workers = g1h->workers()->total_workers();
+
+ G1ParCompleteMarkInCSetTask complete_mark_task(g1h, this);
+
+ assert(g1h->check_cset_heap_region_claim_values(HeapRegion::InitialClaimValue), "sanity");
+
+ if (G1CollectedHeap::use_parallel_gc_threads()) {
+ g1h->set_par_threads(n_workers);
+ g1h->workers()->run_task(&complete_mark_task);
+ g1h->set_par_threads(0);
+ } else {
+ complete_mark_task.work(0);
}
+
+ assert(g1h->check_cset_heap_region_claim_values(HeapRegion::CompleteMarkCSetClaimValue), "sanity");
+
+ // Now reset the claim values in the regions in the collection set.
+ SetClaimValuesInCSetHRClosure set_cv_cl(HeapRegion::InitialClaimValue);
+ g1h->collection_set_iterate(&set_cv_cl);
+
+ assert(g1h->check_cset_heap_region_claim_values(HeapRegion::InitialClaimValue), "sanity");
+
double end_time = os::elapsedTime();
double elapsed_time_ms = (end_time - start) * 1000.0;
g1h->g1_policy()->record_mark_closure_time(elapsed_time_ms);
-
- ClearMarksInHRClosure clr(nextMarkBitMap());
- g1h->collection_set_iterate(&clr);
}
// The next two methods deal with the following optimisation. Some
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -360,7 +360,7 @@
friend class ConcurrentMarkThread;
friend class CMTask;
friend class CMBitMapClosure;
- friend class CSMarkOopClosure;
+ friend class CSetMarkOopClosure;
friend class CMGlobalObjectClosure;
friend class CMRemarkTask;
friend class CMConcurrentMarkingTask;
@@ -375,7 +375,9 @@
ConcurrentMarkThread* _cmThread; // the thread doing the work
G1CollectedHeap* _g1h; // the heap.
size_t _parallel_marking_threads; // the number of marking
- // threads we'll use
+ // threads we're use
+ size_t _max_parallel_marking_threads; // max number of marking
+ // threads we'll ever use
double _sleep_factor; // how much we have to sleep, with
// respect to the work we just did, to
// meet the marking overhead goal
@@ -473,7 +475,7 @@
double* _accum_task_vtime; // accumulated task vtime
- WorkGang* _parallel_workers;
+ FlexibleWorkGang* _parallel_workers;
ForceOverflowSettings _force_overflow_conc;
ForceOverflowSettings _force_overflow_stw;
@@ -504,6 +506,7 @@
// accessor methods
size_t parallel_marking_threads() { return _parallel_marking_threads; }
+ size_t max_parallel_marking_threads() { return _max_parallel_marking_threads;}
double sleep_factor() { return _sleep_factor; }
double marking_task_overhead() { return _marking_task_overhead;}
double cleanup_sleep_factor() { return _cleanup_sleep_factor; }
@@ -709,6 +712,14 @@
CMBitMapRO* prevMarkBitMap() const { return _prevMarkBitMap; }
CMBitMap* nextMarkBitMap() const { return _nextMarkBitMap; }
+ // Returns the number of GC threads to be used in a concurrent
+ // phase based on the number of GC threads being used in a STW
+ // phase.
+ size_t scale_parallel_threads(size_t n_par_threads);
+
+ // Calculates the number of GC threads to be used in a concurrent phase.
+ int calc_parallel_marking_threads();
+
// The following three are interaction between CM and
// G1CollectedHeap
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMarkThread.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMarkThread.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -191,7 +191,11 @@
VM_CGC_Operation op(&cl_cl, verbose_str);
VMThread::execute(&op);
} else {
+ // We don't want to update the marking status if a GC pause
+ // is already underway.
+ _sts.join();
g1h->set_marking_complete();
+ _sts.leave();
}
// Check if cleanup set the free_regions_coming flag. If it
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -66,6 +66,18 @@
// apply to TLAB allocation, which is not part of this interface: it
// is done by clients of this interface.)
+// Notes on implementation of parallelism in different tasks.
+//
+// G1ParVerifyTask uses heap_region_par_iterate_chunked() for parallelism.
+// The number of GC workers is passed to heap_region_par_iterate_chunked().
+// It does use run_task() which sets _n_workers in the task.
+// G1ParTask executes g1_process_strong_roots() ->
+// SharedHeap::process_strong_roots() which calls eventuall to
+// CardTableModRefBS::par_non_clean_card_iterate_work() which uses
+// SequentialSubTasksDone. SharedHeap::process_strong_roots() also
+// directly uses SubTasksDone (_process_strong_tasks field in SharedHeap).
+//
+
// Local to this file.
class RefineCardTableEntryClosure: public CardTableEntryClosure {
@@ -176,8 +188,7 @@
hr->set_next_young_region(_head);
_head = hr;
- hr->set_young();
- double yg_surv_rate = _g1h->g1_policy()->predict_yg_surv_rate((int)_length);
+ _g1h->g1_policy()->set_region_eden(hr, (int) _length);
++_length;
}
@@ -190,7 +201,6 @@
_survivor_tail = hr;
}
_survivor_head = hr;
-
++_survivor_length;
}
@@ -315,16 +325,20 @@
_g1h->g1_policy()->note_start_adding_survivor_regions();
_g1h->g1_policy()->finished_recalculating_age_indexes(true /* is_survivors */);
+ int young_index_in_cset = 0;
for (HeapRegion* curr = _survivor_head;
curr != NULL;
curr = curr->get_next_young_region()) {
- _g1h->g1_policy()->set_region_survivors(curr);
+ _g1h->g1_policy()->set_region_survivor(curr, young_index_in_cset);
// The region is a non-empty survivor so let's add it to
// the incremental collection set for the next evacuation
// pause.
_g1h->g1_policy()->add_region_to_incremental_cset_rhs(curr);
- }
+ young_index_in_cset += 1;
+ }
+ assert((size_t) young_index_in_cset == _survivor_length,
+ "post-condition");
_g1h->g1_policy()->note_stop_adding_survivor_regions();
_head = _survivor_head;
@@ -1154,6 +1168,7 @@
void work(int i) {
RebuildRSOutOfRegionClosure rebuild_rs(_g1, i);
_g1->heap_region_par_iterate_chunked(&rebuild_rs, i,
+ _g1->workers()->active_workers(),
HeapRegion::RebuildRSClaimValue);
}
};
@@ -1358,12 +1373,32 @@
}
// Rebuild remembered sets of all regions.
-
if (G1CollectedHeap::use_parallel_gc_threads()) {
+ int n_workers =
+ AdaptiveSizePolicy::calc_active_workers(workers()->total_workers(),
+ workers()->active_workers(),
+ Threads::number_of_non_daemon_threads());
+ assert(UseDynamicNumberOfGCThreads ||
+ n_workers == workers()->total_workers(),
+ "If not dynamic should be using all the workers");
+ workers()->set_active_workers(n_workers);
+ // Set parallel threads in the heap (_n_par_threads) only
+ // before a parallel phase and always reset it to 0 after
+ // the phase so that the number of parallel threads does
+ // no get carried forward to a serial phase where there
+ // may be code that is "possibly_parallel".
+ set_par_threads(n_workers);
+
ParRebuildRSTask rebuild_rs_task(this);
assert(check_heap_region_claim_values(
HeapRegion::InitialClaimValue), "sanity check");
- set_par_threads(workers()->total_workers());
+ assert(UseDynamicNumberOfGCThreads ||
+ workers()->active_workers() == workers()->total_workers(),
+ "Unless dynamic should use total workers");
+ // Use the most recent number of active workers
+ assert(workers()->active_workers() > 0,
+ "Active workers not properly set");
+ set_par_threads(workers()->active_workers());
workers()->run_task(&rebuild_rs_task);
set_par_threads(0);
assert(check_heap_region_claim_values(
@@ -2475,11 +2510,17 @@
void
G1CollectedHeap::heap_region_par_iterate_chunked(HeapRegionClosure* cl,
int worker,
+ int no_of_par_workers,
jint claim_value) {
const size_t regions = n_regions();
- const size_t worker_num = (G1CollectedHeap::use_parallel_gc_threads() ? ParallelGCThreads : 1);
+ const size_t max_workers = (G1CollectedHeap::use_parallel_gc_threads() ?
+ no_of_par_workers :
+ 1);
+ assert(UseDynamicNumberOfGCThreads ||
+ no_of_par_workers == workers()->total_workers(),
+ "Non dynamic should use fixed number of workers");
// try to spread out the starting points of the workers
- const size_t start_index = regions / worker_num * (size_t) worker;
+ const size_t start_index = regions / max_workers * (size_t) worker;
// each worker will actually look at all regions
for (size_t count = 0; count < regions; ++count) {
@@ -2576,10 +2617,10 @@
_claim_value(claim_value), _failures(0), _sh_region(NULL) { }
bool doHeapRegion(HeapRegion* r) {
if (r->claim_value() != _claim_value) {
- gclog_or_tty->print_cr("Region ["PTR_FORMAT","PTR_FORMAT"), "
+ gclog_or_tty->print_cr("Region " HR_FORMAT ", "
"claim value = %d, should be %d",
- r->bottom(), r->end(), r->claim_value(),
- _claim_value);
+ HR_FORMAT_PARAMS(r),
+ r->claim_value(), _claim_value);
++_failures;
}
if (!r->isHumongous()) {
@@ -2588,9 +2629,9 @@
_sh_region = r;
} else if (r->continuesHumongous()) {
if (r->humongous_start_region() != _sh_region) {
- gclog_or_tty->print_cr("Region ["PTR_FORMAT","PTR_FORMAT"), "
+ gclog_or_tty->print_cr("Region " HR_FORMAT ", "
"HS = "PTR_FORMAT", should be "PTR_FORMAT,
- r->bottom(), r->end(),
+ HR_FORMAT_PARAMS(r),
r->humongous_start_region(),
_sh_region);
++_failures;
@@ -2608,8 +2649,63 @@
heap_region_iterate(&cl);
return cl.failures() == 0;
}
+
+class CheckClaimValuesInCSetHRClosure: public HeapRegionClosure {
+ jint _claim_value;
+ size_t _failures;
+
+public:
+ CheckClaimValuesInCSetHRClosure(jint claim_value) :
+ _claim_value(claim_value),
+ _failures(0) { }
+
+ size_t failures() {
+ return _failures;
+ }
+
+ bool doHeapRegion(HeapRegion* hr) {
+ assert(hr->in_collection_set(), "how?");
+ assert(!hr->isHumongous(), "H-region in CSet");
+ if (hr->claim_value() != _claim_value) {
+ gclog_or_tty->print_cr("CSet Region " HR_FORMAT ", "
+ "claim value = %d, should be %d",
+ HR_FORMAT_PARAMS(hr),
+ hr->claim_value(), _claim_value);
+ _failures += 1;
+ }
+ return false;
+ }
+};
+
+bool G1CollectedHeap::check_cset_heap_region_claim_values(jint claim_value) {
+ CheckClaimValuesInCSetHRClosure cl(claim_value);
+ collection_set_iterate(&cl);
+ return cl.failures() == 0;
+}
#endif // ASSERT
+// We want the parallel threads to start their collection
+// set iteration at different collection set regions to
+// avoid contention.
+// If we have:
+// n collection set regions
+// p threads
+// Then thread t will start at region t * floor (n/p)
+
+HeapRegion* G1CollectedHeap::start_cset_region_for_worker(int worker_i) {
+ HeapRegion* result = g1_policy()->collection_set();
+ if (G1CollectedHeap::use_parallel_gc_threads()) {
+ size_t cs_size = g1_policy()->cset_region_length();
+ int n_workers = workers()->total_workers();
+ size_t cs_spans = cs_size / n_workers;
+ size_t ind = cs_spans * worker_i;
+ for (size_t i = 0; i < ind; i++) {
+ result = result->next_in_collection_set();
+ }
+ }
+ return result;
+}
+
void G1CollectedHeap::collection_set_iterate(HeapRegionClosure* cl) {
HeapRegion* r = g1_policy()->collection_set();
while (r != NULL) {
@@ -2918,6 +3014,7 @@
HandleMark hm;
VerifyRegionClosure blk(_allow_dirty, true, _vo);
_g1h->heap_region_par_iterate_chunked(&blk, worker_i,
+ _g1h->workers()->active_workers(),
HeapRegion::ParVerifyClaimValue);
if (blk.failures()) {
_failures = true;
@@ -2935,6 +3032,10 @@
if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
if (!silent) { gclog_or_tty->print("Roots (excluding permgen) "); }
VerifyRootsClosure rootsCl(vo);
+
+ assert(Thread::current()->is_VM_thread(),
+ "Expected to be executed serially by the VM thread at this point");
+
CodeBlobToOopClosure blobsCl(&rootsCl, /*do_marking=*/ false);
// We apply the relevant closures to all the oops in the
@@ -2979,7 +3080,10 @@
"sanity check");
G1ParVerifyTask task(this, allow_dirty, vo);
- int n_workers = workers()->total_workers();
+ assert(UseDynamicNumberOfGCThreads ||
+ workers()->active_workers() == workers()->total_workers(),
+ "If not dynamic should be using all the workers");
+ int n_workers = workers()->active_workers();
set_par_threads(n_workers);
workers()->run_task(&task);
set_par_threads(0);
@@ -2987,6 +3091,8 @@
failures = true;
}
+ // Checks that the expected amount of parallel work was done.
+ // The implication is that n_workers is > 0.
assert(check_heap_region_claim_values(HeapRegion::ParVerifyClaimValue),
"sanity check");
@@ -3210,8 +3316,6 @@
}
}
-// <NEW PREDICTION>
-
double G1CollectedHeap::predict_region_elapsed_time_ms(HeapRegion *hr,
bool young) {
return _g1_policy->predict_region_elapsed_time_ms(hr, young);
@@ -3251,7 +3355,7 @@
void
G1CollectedHeap::setup_surviving_young_words() {
guarantee( _surviving_young_words == NULL, "pre-condition" );
- size_t array_length = g1_policy()->young_cset_length();
+ size_t array_length = g1_policy()->young_cset_region_length();
_surviving_young_words = NEW_C_HEAP_ARRAY(size_t, array_length);
if (_surviving_young_words == NULL) {
vm_exit_out_of_memory(sizeof(size_t) * array_length,
@@ -3268,7 +3372,7 @@
void
G1CollectedHeap::update_surviving_young_words(size_t* surv_young_words) {
MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
- size_t array_length = g1_policy()->young_cset_length();
+ size_t array_length = g1_policy()->young_cset_region_length();
for (size_t i = 0; i < array_length; ++i)
_surviving_young_words[i] += surv_young_words[i];
}
@@ -3280,8 +3384,6 @@
_surviving_young_words = NULL;
}
-// </NEW PREDICTION>
-
#ifdef ASSERT
class VerifyCSetClosure: public HeapRegionClosure {
public:
@@ -3404,6 +3506,10 @@
assert(check_young_list_well_formed(),
"young list should be well formed");
+ // Don't dynamically change the number of GC threads this early. A value of
+ // 0 is used to indicate serial work. When parallel work is done,
+ // it will be set.
+
{ // Call to jvmpi::post_class_unload_events must occur outside of active GC
IsGCActiveMark x;
@@ -3617,7 +3723,8 @@
double end_time_sec = os::elapsedTime();
double pause_time_ms = (end_time_sec - start_time_sec) * MILLIUNITS;
g1_policy()->record_pause_time_ms(pause_time_ms);
- g1_policy()->record_collection_pause_end();
+ int active_gc_threads = workers()->active_workers();
+ g1_policy()->record_collection_pause_end(active_gc_threads);
MemoryService::track_memory_usage();
@@ -4158,7 +4265,7 @@
// non-young regions (where the age is -1)
// We also add a few elements at the beginning and at the end in
// an attempt to eliminate cache contention
- size_t real_length = 1 + _g1h->g1_policy()->young_cset_length();
+ size_t real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
size_t array_length = PADDING_ELEM_NUM +
real_length +
PADDING_ELEM_NUM;
@@ -4564,13 +4671,13 @@
}
public:
- G1ParTask(G1CollectedHeap* g1h, int workers, RefToScanQueueSet *task_queues)
+ G1ParTask(G1CollectedHeap* g1h,
+ RefToScanQueueSet *task_queues)
: AbstractGangTask("G1 collection"),
_g1h(g1h),
_queues(task_queues),
- _terminator(workers, _queues),
- _stats_lock(Mutex::leaf, "parallel G1 stats lock", true),
- _n_workers(workers)
+ _terminator(0, _queues),
+ _stats_lock(Mutex::leaf, "parallel G1 stats lock", true)
{}
RefToScanQueueSet* queues() { return _queues; }
@@ -4579,6 +4686,20 @@
return queues()->queue(i);
}
+ ParallelTaskTerminator* terminator() { return &_terminator; }
+
+ virtual void set_for_termination(int active_workers) {
+ // This task calls set_n_termination() in par_non_clean_card_iterate_work()
+ // in the young space (_par_seq_tasks) in the G1 heap
+ // for SequentialSubTasksDone.
+ // This task also uses SubTasksDone in SharedHeap and G1CollectedHeap
+ // both of which need setting by set_n_termination().
+ _g1h->SharedHeap::set_n_termination(active_workers);
+ _g1h->set_n_termination(active_workers);
+ terminator()->reset_for_reuse(active_workers);
+ _n_workers = active_workers;
+ }
+
void work(int i) {
if (i >= _n_workers) return; // no work needed this round
@@ -4863,12 +4984,12 @@
private:
G1CollectedHeap* _g1h;
RefToScanQueueSet* _queues;
- WorkGang* _workers;
+ FlexibleWorkGang* _workers;
int _active_workers;
public:
G1STWRefProcTaskExecutor(G1CollectedHeap* g1h,
- WorkGang* workers,
+ FlexibleWorkGang* workers,
RefToScanQueueSet *task_queues,
int n_workers) :
_g1h(g1h),
@@ -5124,11 +5245,13 @@
// referents points to another object which is also referenced by an
// object discovered by the STW ref processor.
- int n_workers = (G1CollectedHeap::use_parallel_gc_threads() ?
- workers()->total_workers() : 1);
-
- set_par_threads(n_workers);
- G1ParPreserveCMReferentsTask keep_cm_referents(this, n_workers, _task_queues);
+ int active_workers = (G1CollectedHeap::use_parallel_gc_threads() ?
+ workers()->active_workers() : 1);
+
+ assert(active_workers == workers()->active_workers(),
+ "Need to reset active_workers");
+ set_par_threads(active_workers);
+ G1ParPreserveCMReferentsTask keep_cm_referents(this, active_workers, _task_queues);
if (G1CollectedHeap::use_parallel_gc_threads()) {
workers()->run_task(&keep_cm_referents);
@@ -5194,7 +5317,6 @@
NULL);
} else {
// Parallel reference processing
- int active_workers = (ParallelGCThreads > 0 ? workers()->total_workers() : 1);
assert(rp->num_q() == active_workers, "sanity");
assert(active_workers <= rp->max_num_q(), "sanity");
@@ -5227,7 +5349,9 @@
} else {
// Parallel reference enqueuing
- int active_workers = (ParallelGCThreads > 0 ? workers()->total_workers() : 1);
+ int active_workers = (ParallelGCThreads > 0 ? workers()->active_workers() : 1);
+ assert(active_workers == workers()->active_workers(),
+ "Need to reset active_workers");
assert(rp->num_q() == active_workers, "sanity");
assert(active_workers <= rp->max_num_q(), "sanity");
@@ -5254,9 +5378,24 @@
concurrent_g1_refine()->set_use_cache(false);
concurrent_g1_refine()->clear_hot_cache_claimed_index();
- int n_workers = (ParallelGCThreads > 0 ? workers()->total_workers() : 1);
- set_par_threads(n_workers);
- G1ParTask g1_par_task(this, n_workers, _task_queues);
+ int n_workers;
+ if (G1CollectedHeap::use_parallel_gc_threads()) {
+ n_workers =
+ AdaptiveSizePolicy::calc_active_workers(workers()->total_workers(),
+ workers()->active_workers(),
+ Threads::number_of_non_daemon_threads());
+ assert(UseDynamicNumberOfGCThreads ||
+ n_workers == workers()->total_workers(),
+ "If not dynamic should be using all the workers");
+ set_par_threads(n_workers);
+ } else {
+ assert(n_par_threads() == 0,
+ "Should be the original non-parallel value");
+ n_workers = 1;
+ }
+ workers()->set_active_workers(n_workers);
+
+ G1ParTask g1_par_task(this, _task_queues);
init_for_evac_failure(NULL);
@@ -5269,6 +5408,10 @@
// The individual threads will set their evac-failure closures.
StrongRootsScope srs(this);
if (ParallelGCVerbose) G1ParScanThreadState::print_termination_stats_hdr();
+ // These tasks use ShareHeap::_process_strong_tasks
+ assert(UseDynamicNumberOfGCThreads ||
+ workers()->active_workers() == workers()->total_workers(),
+ "If not dynamic should be using all the workers");
workers()->run_task(&g1_par_task);
} else {
StrongRootsScope srs(this);
@@ -5277,6 +5420,7 @@
double par_time = (os::elapsedTime() - start_par) * 1000.0;
g1_policy()->record_par_time(par_time);
+
set_par_threads(0);
// Process any discovered reference objects - we have
@@ -5304,8 +5448,11 @@
finalize_for_evac_failure();
- // Must do this before removing self-forwarding pointers, which clears
- // the per-region evac-failure flags.
+ // Must do this before clearing the per-region evac-failure flags
+ // (which is currently done when we free the collection set).
+ // We also only do this if marking is actually in progress and so
+ // have to do this before we set the mark_in_progress flag at the
+ // end of an initial mark pause.
concurrent_mark()->complete_marking_in_collection_set();
if (evacuation_failed()) {
@@ -5567,7 +5714,6 @@
while (cur != NULL) {
assert(!is_on_master_free_list(cur), "sanity");
-
if (non_young) {
if (cur->is_young()) {
double end_sec = os::elapsedTime();
@@ -5578,12 +5724,14 @@
non_young = false;
}
} else {
- double end_sec = os::elapsedTime();
- double elapsed_ms = (end_sec - start_sec) * 1000.0;
- young_time_ms += elapsed_ms;
-
- start_sec = os::elapsedTime();
- non_young = true;
+ if (!cur->is_young()) {
+ double end_sec = os::elapsedTime();
+ double elapsed_ms = (end_sec - start_sec) * 1000.0;
+ young_time_ms += elapsed_ms;
+
+ start_sec = os::elapsedTime();
+ non_young = true;
+ }
}
rs_lengths += cur->rem_set()->occupied();
@@ -5595,8 +5743,8 @@
if (cur->is_young()) {
int index = cur->young_index_in_cset();
- guarantee( index != -1, "invariant" );
- guarantee( (size_t)index < policy->young_cset_length(), "invariant" );
+ assert(index != -1, "invariant");
+ assert((size_t) index < policy->young_cset_region_length(), "invariant");
size_t words_survived = _surviving_young_words[index];
cur->record_surv_words_in_group(words_survived);
@@ -5607,7 +5755,7 @@
cur->set_next_young_region(NULL);
} else {
int index = cur->young_index_in_cset();
- guarantee( index == -1, "invariant" );
+ assert(index == -1, "invariant");
}
assert( (cur->is_young() && cur->young_index_in_cset() > -1) ||
@@ -5615,13 +5763,26 @@
"invariant" );
if (!cur->evacuation_failed()) {
+ MemRegion used_mr = cur->used_region();
+
// And the region is empty.
- assert(!cur->is_empty(), "Should not have empty regions in a CS.");
+ assert(!used_mr.is_empty(), "Should not have empty regions in a CS.");
+
+ // If marking is in progress then clear any objects marked in
+ // the current region. Note mark_in_progress() returns false,
+ // even during an initial mark pause, until the set_marking_started()
+ // call which takes place later in the pause.
+ if (mark_in_progress()) {
+ assert(!g1_policy()->during_initial_mark_pause(), "sanity");
+ _cm->nextMarkBitMap()->clearRange(used_mr);
+ }
+
free_region(cur, &pre_used, &local_free_list, false /* par */);
} else {
cur->uninstall_surv_rate_group();
- if (cur->is_young())
+ if (cur->is_young()) {
cur->set_young_index_in_cset(-1);
+ }
cur->set_not_young();
cur->set_evacuation_failed(false);
// The region is now considered to be old.
@@ -5635,10 +5796,12 @@
double end_sec = os::elapsedTime();
double elapsed_ms = (end_sec - start_sec) * 1000.0;
- if (non_young)
+
+ if (non_young) {
non_young_time_ms += elapsed_ms;
- else
+ } else {
young_time_ms += elapsed_ms;
+ }
update_sets_after_freeing_regions(pre_used, &local_free_list,
NULL /* old_proxy_set */,
@@ -5722,7 +5885,6 @@
assert(heap_lock_held_for_gc(),
"the heap lock should already be held by or for this thread");
_young_list->push_region(hr);
- g1_policy()->set_region_short_lived(hr);
}
class NoYoungRegionsClosure: public HeapRegionClosure {
@@ -5880,7 +6042,6 @@
HeapRegion* new_alloc_region = new_region(word_size,
false /* do_expand */);
if (new_alloc_region != NULL) {
- g1_policy()->update_region_num(true /* next_is_young */);
set_region_short_lived_locked(new_alloc_region);
_hr_printer.alloc(new_alloc_region, G1HRPrinter::Eden, young_list_full);
return new_alloc_region;
@@ -5908,6 +6069,21 @@
return _g1h->new_mutator_alloc_region(word_size, force);
}
+void G1CollectedHeap::set_par_threads() {
+ // Don't change the number of workers. Use the value previously set
+ // in the workgroup.
+ int n_workers = workers()->active_workers();
+ assert(UseDynamicNumberOfGCThreads ||
+ n_workers == workers()->total_workers(),
+ "Otherwise should be using the total number of workers");
+ if (n_workers == 0) {
+ assert(false, "Should have been set in prior evacuation pause.");
+ n_workers = ParallelGCThreads;
+ workers()->set_active_workers(n_workers);
+ }
+ set_par_threads(n_workers);
+}
+
void MutatorAllocRegion::retire_region(HeapRegion* alloc_region,
size_t allocated_bytes) {
_g1h->retire_mutator_alloc_region(alloc_region, allocated_bytes);
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -987,6 +987,16 @@
void set_par_threads(int t) {
SharedHeap::set_par_threads(t);
+ // Done in SharedHeap but oddly there are
+ // two _process_strong_tasks's in a G1CollectedHeap
+ // so do it here too.
+ _process_strong_tasks->set_n_threads(t);
+ }
+
+ // Set _n_par_threads according to a policy TBD.
+ void set_par_threads();
+
+ void set_n_termination(int t) {
_process_strong_tasks->set_n_threads(t);
}
@@ -1276,6 +1286,7 @@
// i.e., that a closure never attempt to abort a traversal.
void heap_region_par_iterate_chunked(HeapRegionClosure* blk,
int worker,
+ int no_of_par_workers,
jint claim_value);
// It resets all the region claim values to the default.
@@ -1283,8 +1294,17 @@
#ifdef ASSERT
bool check_heap_region_claim_values(jint claim_value);
+
+ // Same as the routine above but only checks regions in the
+ // current collection set.
+ bool check_cset_heap_region_claim_values(jint claim_value);
#endif // ASSERT
+ // Given the id of a worker, calculate a suitable
+ // starting region for iterating over the current
+ // collection set.
+ HeapRegion* start_cset_region_for_worker(int worker_i);
+
// Iterate over the regions (if any) in the current collection set.
void collection_set_iterate(HeapRegionClosure* blk);
@@ -1610,16 +1630,12 @@
public:
void stop_conc_gc_threads();
- // <NEW PREDICTION>
-
double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);
void check_if_region_is_too_expensive(double predicted_time_ms);
size_t pending_card_num();
size_t max_pending_card_num();
size_t cards_scanned();
- // </NEW PREDICTION>
-
protected:
size_t _max_heap_capacity;
};
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -36,10 +36,6 @@
#include "runtime/mutexLocker.hpp"
#include "utilities/debug.hpp"
-#define PREDICTIONS_VERBOSE 0
-
-// <NEW PREDICTION>
-
// Different defaults for different number of GC threads
// They were chosen by running GCOld and SPECjbb on debris with different
// numbers of GC threads and choosing them based on the results
@@ -80,8 +76,6 @@
1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
};
-// </NEW PREDICTION>
-
// Help class for avoiding interleaved logging
class LineBuffer: public StackObj {
@@ -137,10 +131,6 @@
_parallel_gc_threads(G1CollectedHeap::use_parallel_gc_threads()
? ParallelGCThreads : 1),
- _n_pauses(0),
- _recent_rs_scan_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
- _recent_pause_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
- _recent_rs_sizes(new TruncatedSeq(NumPrevPausesForHeuristics)),
_recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
_all_pause_times_ms(new NumberSeq()),
_stop_world_start(0.0),
@@ -148,11 +138,10 @@
_all_yield_times_ms(new NumberSeq()),
_using_new_ratio_calculations(false),
- _all_mod_union_times_ms(new NumberSeq()),
-
_summary(new Summary()),
_cur_clear_ct_time_ms(0.0),
+ _mark_closure_time_ms(0.0),
_cur_ref_proc_time_ms(0.0),
_cur_ref_enq_time_ms(0.0),
@@ -165,11 +154,6 @@
_num_cc_clears(0L),
#endif
- _region_num_young(0),
- _region_num_tenured(0),
- _prev_region_num_young(0),
- _prev_region_num_tenured(0),
-
_aux_num(10),
_all_aux_times_ms(new NumberSeq[_aux_num]),
_cur_aux_start_times_ms(new double[_aux_num]),
@@ -179,8 +163,6 @@
_concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
_concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
- // <NEW PREDICTION>
-
_alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
_prev_collection_pause_end_ms(0.0),
_pending_card_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
@@ -199,13 +181,10 @@
new TruncatedSeq(TruncatedSeqLength)),
_pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
- _scanned_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
_rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)),
_pause_time_target_ms((double) MaxGCPauseMillis),
- // </NEW PREDICTION>
-
_full_young_gcs(true),
_full_young_pause_num(0),
_partial_young_pause_num(0),
@@ -221,16 +200,10 @@
_recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)),
- _recent_CS_bytes_used_before(new TruncatedSeq(NumPrevPausesForHeuristics)),
- _recent_CS_bytes_surviving(new TruncatedSeq(NumPrevPausesForHeuristics)),
-
_recent_avg_pause_time_ratio(0.0),
_all_full_gc_times_ms(new NumberSeq()),
- // G1PausesBtwnConcMark defaults to -1
- // so the hack is to do the cast QQQ FIXME
- _pauses_btwn_concurrent_mark((size_t)G1PausesBtwnConcMark),
_initiate_conc_mark_if_possible(false),
_during_initial_mark_pause(false),
_should_revert_to_full_young_gcs(false),
@@ -242,22 +215,21 @@
_prev_collection_pause_used_at_end_bytes(0),
+ _eden_cset_region_length(0),
+ _survivor_cset_region_length(0),
+ _old_cset_region_length(0),
+
_collection_set(NULL),
- _collection_set_size(0),
_collection_set_bytes_used_before(0),
// Incremental CSet attributes
_inc_cset_build_state(Inactive),
_inc_cset_head(NULL),
_inc_cset_tail(NULL),
- _inc_cset_size(0),
- _inc_cset_young_index(0),
_inc_cset_bytes_used_before(0),
_inc_cset_max_finger(NULL),
- _inc_cset_recorded_young_bytes(0),
_inc_cset_recorded_rs_lengths(0),
_inc_cset_predicted_elapsed_time_ms(0.0),
- _inc_cset_predicted_bytes_to_copy(0),
#ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
#pragma warning( disable:4355 ) // 'this' : used in base member initializer list
@@ -325,8 +297,6 @@
// start conservatively
_expensive_region_limit_ms = 0.5 * (double) MaxGCPauseMillis;
- // <NEW PREDICTION>
-
int index;
if (ParallelGCThreads == 0)
index = 0;
@@ -348,8 +318,6 @@
_non_young_other_cost_per_region_ms_seq->add(
non_young_other_cost_per_region_ms_defaults[index]);
- // </NEW PREDICTION>
-
// Below, we might need to calculate the pause time target based on
// the pause interval. When we do so we are going to give G1 maximum
// flexibility and allow it to do pauses when it needs to. So, we'll
@@ -908,9 +876,6 @@
record_survivor_regions(0, NULL, NULL);
- _prev_region_num_young = _region_num_young;
- _prev_region_num_tenured = _region_num_tenured;
-
_free_regions_at_end_of_collection = _g1->free_regions();
// Reset survivors SurvRateGroup.
_survivor_surv_rate_group->reset();
@@ -982,10 +947,9 @@
_cur_aux_times_set[i] = false;
}
- // These are initialized to zero here and they are set during
+ // This is initialized to zero here and is set during
// the evacuation pause if marking is in progress.
_cur_satb_drain_time_ms = 0.0;
- _last_satb_drain_processed_buffers = 0;
_last_young_gc_full = false;
@@ -996,10 +960,6 @@
assert( verify_young_ages(), "region age verification" );
}
-void G1CollectorPolicy::record_mark_closure_time(double mark_closure_time_ms) {
- _mark_closure_time_ms = mark_closure_time_ms;
-}
-
void G1CollectorPolicy::record_concurrent_mark_init_end(double
mark_init_elapsed_time_ms) {
_during_marking = true;
@@ -1060,7 +1020,7 @@
double total = 0.0;
LineBuffer buf(level);
buf.append("[%s (ms):", str);
- for (uint i = 0; i < ParallelGCThreads; ++i) {
+ for (uint i = 0; i < no_of_gc_threads(); ++i) {
double val = data[i];
if (val < min)
min = val;
@@ -1070,7 +1030,7 @@
buf.append(" %3.1lf", val);
}
buf.append_and_print_cr("");
- double avg = total / (double) ParallelGCThreads;
+ double avg = total / (double) no_of_gc_threads();
buf.append_and_print_cr(" Avg: %5.1lf, Min: %5.1lf, Max: %5.1lf, Diff: %5.1lf]",
avg, min, max, max - min);
}
@@ -1082,7 +1042,7 @@
double total = 0.0;
LineBuffer buf(level);
buf.append("[%s :", str);
- for (uint i = 0; i < ParallelGCThreads; ++i) {
+ for (uint i = 0; i < no_of_gc_threads(); ++i) {
double val = data[i];
if (val < min)
min = val;
@@ -1092,7 +1052,7 @@
buf.append(" %d", (int) val);
}
buf.append_and_print_cr("");
- double avg = total / (double) ParallelGCThreads;
+ double avg = total / (double) no_of_gc_threads();
buf.append_and_print_cr(" Sum: %d, Avg: %d, Min: %d, Max: %d, Diff: %d]",
(int)total, (int)avg, (int)min, (int)max, (int)max - (int)min);
}
@@ -1112,10 +1072,10 @@
double G1CollectorPolicy::avg_value(double* data) {
if (G1CollectedHeap::use_parallel_gc_threads()) {
double ret = 0.0;
- for (uint i = 0; i < ParallelGCThreads; ++i) {
+ for (uint i = 0; i < no_of_gc_threads(); ++i) {
ret += data[i];
}
- return ret / (double) ParallelGCThreads;
+ return ret / (double) no_of_gc_threads();
} else {
return data[0];
}
@@ -1124,7 +1084,7 @@
double G1CollectorPolicy::max_value(double* data) {
if (G1CollectedHeap::use_parallel_gc_threads()) {
double ret = data[0];
- for (uint i = 1; i < ParallelGCThreads; ++i) {
+ for (uint i = 1; i < no_of_gc_threads(); ++i) {
if (data[i] > ret) {
ret = data[i];
}
@@ -1138,7 +1098,7 @@
double G1CollectorPolicy::sum_of_values(double* data) {
if (G1CollectedHeap::use_parallel_gc_threads()) {
double sum = 0.0;
- for (uint i = 0; i < ParallelGCThreads; i++) {
+ for (uint i = 0; i < no_of_gc_threads(); i++) {
sum += data[i];
}
return sum;
@@ -1151,7 +1111,7 @@
double ret = data1[0] + data2[0];
if (G1CollectedHeap::use_parallel_gc_threads()) {
- for (uint i = 1; i < ParallelGCThreads; ++i) {
+ for (uint i = 1; i < no_of_gc_threads(); ++i) {
double data = data1[i] + data2[i];
if (data > ret) {
ret = data;
@@ -1164,16 +1124,19 @@
// Anything below that is considered to be zero
#define MIN_TIMER_GRANULARITY 0.0000001
-void G1CollectorPolicy::record_collection_pause_end() {
+void G1CollectorPolicy::record_collection_pause_end(int no_of_gc_threads) {
double end_time_sec = os::elapsedTime();
double elapsed_ms = _last_pause_time_ms;
bool parallel = G1CollectedHeap::use_parallel_gc_threads();
+ assert(_cur_collection_pause_used_regions_at_start >= cset_region_length(),
+ "otherwise, the subtraction below does not make sense");
size_t rs_size =
- _cur_collection_pause_used_regions_at_start - collection_set_size();
+ _cur_collection_pause_used_regions_at_start - cset_region_length();
size_t cur_used_bytes = _g1->used();
assert(cur_used_bytes == _g1->recalculate_used(), "It should!");
bool last_pause_included_initial_mark = false;
bool update_stats = !_g1->evacuation_failed();
+ set_no_of_gc_threads(no_of_gc_threads);
#ifndef PRODUCT
if (G1YoungSurvRateVerbose) {
@@ -1226,10 +1189,6 @@
_mmu_tracker->add_pause(end_time_sec - elapsed_ms/1000.0,
end_time_sec, false);
- guarantee(_cur_collection_pause_used_regions_at_start >=
- collection_set_size(),
- "Negative RS size?");
-
// This assert is exempted when we're doing parallel collection pauses,
// because the fragmentation caused by the parallel GC allocation buffers
// can lead to more memory being used during collection than was used
@@ -1253,8 +1212,6 @@
(double)surviving_bytes/
(double)_collection_set_bytes_used_before;
- _n_pauses++;
-
// These values are used to update the summary information that is
// displayed when TraceGen0Time is enabled, and are output as part
// of the PrintGCDetails output, in the non-parallel case.
@@ -1291,14 +1248,15 @@
// current value of "other time"
other_time_ms -= _cur_clear_ct_time_ms;
+ // Subtract the time spent completing marking in the collection
+ // set. Note if marking is not in progress during the pause
+ // the value of _mark_closure_time_ms will be zero.
+ other_time_ms -= _mark_closure_time_ms;
+
// TraceGen0Time and TraceGen1Time summary info updating.
_all_pause_times_ms->add(elapsed_ms);
if (update_stats) {
- _recent_rs_scan_times_ms->add(scan_rs_time);
- _recent_pause_times_ms->add(elapsed_ms);
- _recent_rs_sizes->add(rs_size);
-
_summary->record_total_time_ms(elapsed_ms);
_summary->record_other_time_ms(other_time_ms);
@@ -1342,9 +1300,6 @@
|| surviving_bytes <= _collection_set_bytes_used_before,
"Or else negative collection!");
- _recent_CS_bytes_used_before->add(_collection_set_bytes_used_before);
- _recent_CS_bytes_surviving->add(surviving_bytes);
-
// this is where we update the allocation rate of the application
double app_time_ms =
(_cur_collection_start_sec * 1000.0 - _prev_collection_pause_end_ms);
@@ -1354,13 +1309,17 @@
// We'll just set it to something (arbitrarily) small.
app_time_ms = 1.0;
}
- size_t regions_allocated =
- (_region_num_young - _prev_region_num_young) +
- (_region_num_tenured - _prev_region_num_tenured);
+ // We maintain the invariant that all objects allocated by mutator
+ // threads will be allocated out of eden regions. So, we can use
+ // the eden region number allocated since the previous GC to
+ // calculate the application's allocate rate. The only exception
+ // to that is humongous objects that are allocated separately. But
+ // given that humongous object allocations do not really affect
+ // either the pause's duration nor when the next pause will take
+ // place we can safely ignore them here.
+ size_t regions_allocated = eden_cset_region_length();
double alloc_rate_ms = (double) regions_allocated / app_time_ms;
_alloc_rate_ms_seq->add(alloc_rate_ms);
- _prev_region_num_young = _region_num_young;
- _prev_region_num_tenured = _region_num_tenured;
double interval_ms =
(end_time_sec - _recent_prev_end_times_for_all_gcs_sec->oldest()) * 1000.0;
@@ -1398,33 +1357,6 @@
}
}
-
- if (G1PolicyVerbose > 1) {
- gclog_or_tty->print_cr(" Recording collection pause(%d)", _n_pauses);
- }
-
- if (G1PolicyVerbose > 1) {
- gclog_or_tty->print_cr(" ET: %10.6f ms (avg: %10.6f ms)\n"
- " ET-RS: %10.6f ms (avg: %10.6f ms)\n"
- " |RS|: " SIZE_FORMAT,
- elapsed_ms, recent_avg_time_for_pauses_ms(),
- scan_rs_time, recent_avg_time_for_rs_scan_ms(),
- rs_size);
-
- gclog_or_tty->print_cr(" Used at start: " SIZE_FORMAT"K"
- " At end " SIZE_FORMAT "K\n"
- " garbage : " SIZE_FORMAT "K"
- " of " SIZE_FORMAT "K\n"
- " survival : %6.2f%% (%6.2f%% avg)",
- _cur_collection_pause_used_at_start_bytes/K,
- _g1->used()/K, freed_bytes/K,
- _collection_set_bytes_used_before/K,
- survival_fraction*100.0,
- recent_avg_survival_fraction()*100.0);
- gclog_or_tty->print_cr(" Recent %% gc pause time: %6.2f",
- recent_avg_pause_time_ratio() * 100.0);
- }
-
// PrintGCDetails output
if (PrintGCDetails) {
bool print_marking_info =
@@ -1436,7 +1368,6 @@
if (print_marking_info) {
print_stats(1, "SATB Drain Time", _cur_satb_drain_time_ms);
- print_stats(2, "Processed Buffers", _last_satb_drain_processed_buffers);
}
if (parallel) {
@@ -1478,6 +1409,9 @@
print_stats(1, "Scan RS", scan_rs_time);
print_stats(1, "Object Copying", obj_copy_time);
}
+ if (print_marking_info) {
+ print_stats(1, "Complete CSet Marking", _mark_closure_time_ms);
+ }
print_stats(1, "Clear CT", _cur_clear_ct_time_ms);
#ifndef PRODUCT
print_stats(1, "Cur Clear CC", _cur_clear_cc_time_ms);
@@ -1489,9 +1423,14 @@
}
#endif
print_stats(1, "Other", other_time_ms);
- print_stats(2, "Choose CSet", _recorded_young_cset_choice_time_ms);
+ print_stats(2, "Choose CSet",
+ (_recorded_young_cset_choice_time_ms +
+ _recorded_non_young_cset_choice_time_ms));
print_stats(2, "Ref Proc", _cur_ref_proc_time_ms);
print_stats(2, "Ref Enq", _cur_ref_enq_time_ms);
+ print_stats(2, "Free CSet",
+ (_recorded_young_free_cset_time_ms +
+ _recorded_non_young_free_cset_time_ms));
for (int i = 0; i < _aux_num; ++i) {
if (_cur_aux_times_set[i]) {
@@ -1576,8 +1515,6 @@
_short_lived_surv_rate_group->start_adding_regions();
// do that for any other surv rate groupsx
- // <NEW PREDICTION>
-
if (update_stats) {
double pause_time_ms = elapsed_ms;
@@ -1631,21 +1568,21 @@
_mark_closure_time_ms + termination_time);
double young_other_time_ms = 0.0;
- if (_recorded_young_regions > 0) {
+ if (young_cset_region_length() > 0) {
young_other_time_ms =
_recorded_young_cset_choice_time_ms +
_recorded_young_free_cset_time_ms;
_young_other_cost_per_region_ms_seq->add(young_other_time_ms /
- (double) _recorded_young_regions);
+ (double) young_cset_region_length());
}
double non_young_other_time_ms = 0.0;
- if (_recorded_non_young_regions > 0) {
+ if (old_cset_region_length() > 0) {
non_young_other_time_ms =
_recorded_non_young_cset_choice_time_ms +
_recorded_non_young_free_cset_time_ms;
_non_young_other_cost_per_region_ms_seq->add(non_young_other_time_ms /
- (double) _recorded_non_young_regions);
+ (double) old_cset_region_length());
}
double constant_other_time_ms = all_other_time_ms -
@@ -1659,7 +1596,6 @@
}
_pending_cards_seq->add((double) _pending_cards);
- _scanned_cards_seq->add((double) cards_scanned);
_rs_lengths_seq->add((double) _max_rs_lengths);
double expensive_region_limit_ms =
@@ -1670,49 +1606,6 @@
expensive_region_limit_ms = (double) MaxGCPauseMillis;
}
_expensive_region_limit_ms = expensive_region_limit_ms;
-
- if (PREDICTIONS_VERBOSE) {
- gclog_or_tty->print_cr("");
- gclog_or_tty->print_cr("PREDICTIONS %1.4lf %d "
- "REGIONS %d %d %d "
- "PENDING_CARDS %d %d "
- "CARDS_SCANNED %d %d "
- "RS_LENGTHS %d %d "
- "RS_UPDATE %1.6lf %1.6lf RS_SCAN %1.6lf %1.6lf "
- "SURVIVAL_RATIO %1.6lf %1.6lf "
- "OBJECT_COPY %1.6lf %1.6lf OTHER_CONSTANT %1.6lf %1.6lf "
- "OTHER_YOUNG %1.6lf %1.6lf "
- "OTHER_NON_YOUNG %1.6lf %1.6lf "
- "VTIME_DIFF %1.6lf TERMINATION %1.6lf "
- "ELAPSED %1.6lf %1.6lf ",
- _cur_collection_start_sec,
- (!_last_young_gc_full) ? 2 :
- (last_pause_included_initial_mark) ? 1 : 0,
- _recorded_region_num,
- _recorded_young_regions,
- _recorded_non_young_regions,
- _predicted_pending_cards, _pending_cards,
- _predicted_cards_scanned, cards_scanned,
- _predicted_rs_lengths, _max_rs_lengths,
- _predicted_rs_update_time_ms, update_rs_time,
- _predicted_rs_scan_time_ms, scan_rs_time,
- _predicted_survival_ratio, survival_ratio,
- _predicted_object_copy_time_ms, obj_copy_time,
- _predicted_constant_other_time_ms, constant_other_time_ms,
- _predicted_young_other_time_ms, young_other_time_ms,
- _predicted_non_young_other_time_ms,
- non_young_other_time_ms,
- _vtime_diff_ms, termination_time,
- _predicted_pause_time_ms, elapsed_ms);
- }
-
- if (G1PolicyVerbose > 0) {
- gclog_or_tty->print_cr("Pause Time, predicted: %1.4lfms (predicted %s), actual: %1.4lfms",
- _predicted_pause_time_ms,
- (_within_target) ? "within" : "outside",
- elapsed_ms);
- }
-
}
_in_marking_window = new_in_marking_window;
@@ -1723,7 +1616,6 @@
// Note that _mmu_tracker->max_gc_time() returns the time in seconds.
double update_rs_time_goal_ms = _mmu_tracker->max_gc_time() * MILLIUNITS * G1RSetUpdatingPauseTimePercent / 100.0;
adjust_concurrent_refinement(update_rs_time, update_rs_processed_buffers, update_rs_time_goal_ms);
- // </NEW PREDICTION>
assert(assertMarkedBytesDataOK(), "Marked regions not OK at pause end.");
}
@@ -1768,8 +1660,6 @@
}
}
-// <NEW PREDICTION>
-
void G1CollectorPolicy::adjust_concurrent_refinement(double update_rs_time,
double update_rs_processed_buffers,
double goal_ms) {
@@ -1905,98 +1795,17 @@
}
void
-G1CollectorPolicy::start_recording_regions() {
- _recorded_rs_lengths = 0;
- _recorded_young_regions = 0;
- _recorded_non_young_regions = 0;
-
-#if PREDICTIONS_VERBOSE
- _recorded_marked_bytes = 0;
- _recorded_young_bytes = 0;
- _predicted_bytes_to_copy = 0;
- _predicted_rs_lengths = 0;
- _predicted_cards_scanned = 0;
-#endif // PREDICTIONS_VERBOSE
-}
-
-void
-G1CollectorPolicy::record_cset_region_info(HeapRegion* hr, bool young) {
-#if PREDICTIONS_VERBOSE
- if (!young) {
- _recorded_marked_bytes += hr->max_live_bytes();
- }
- _predicted_bytes_to_copy += predict_bytes_to_copy(hr);
-#endif // PREDICTIONS_VERBOSE
-
- size_t rs_length = hr->rem_set()->occupied();
- _recorded_rs_lengths += rs_length;
-}
-
-void
-G1CollectorPolicy::record_non_young_cset_region(HeapRegion* hr) {
- assert(!hr->is_young(), "should not call this");
- ++_recorded_non_young_regions;
- record_cset_region_info(hr, false);
-}
-
-void
-G1CollectorPolicy::set_recorded_young_regions(size_t n_regions) {
- _recorded_young_regions = n_regions;
-}
-
-void G1CollectorPolicy::set_recorded_young_bytes(size_t bytes) {
-#if PREDICTIONS_VERBOSE
- _recorded_young_bytes = bytes;
-#endif // PREDICTIONS_VERBOSE
+G1CollectorPolicy::init_cset_region_lengths(size_t eden_cset_region_length,
+ size_t survivor_cset_region_length) {
+ _eden_cset_region_length = eden_cset_region_length;
+ _survivor_cset_region_length = survivor_cset_region_length;
+ _old_cset_region_length = 0;
}
void G1CollectorPolicy::set_recorded_rs_lengths(size_t rs_lengths) {
_recorded_rs_lengths = rs_lengths;
}
-void G1CollectorPolicy::set_predicted_bytes_to_copy(size_t bytes) {
- _predicted_bytes_to_copy = bytes;
-}
-
-void
-G1CollectorPolicy::end_recording_regions() {
- // The _predicted_pause_time_ms field is referenced in code
- // not under PREDICTIONS_VERBOSE. Let's initialize it.
- _predicted_pause_time_ms = -1.0;
-
-#if PREDICTIONS_VERBOSE
- _predicted_pending_cards = predict_pending_cards();
- _predicted_rs_lengths = _recorded_rs_lengths + predict_rs_length_diff();
- if (full_young_gcs())
- _predicted_cards_scanned += predict_young_card_num(_predicted_rs_lengths);
- else
- _predicted_cards_scanned +=
- predict_non_young_card_num(_predicted_rs_lengths);
- _recorded_region_num = _recorded_young_regions + _recorded_non_young_regions;
-
- _predicted_rs_update_time_ms =
- predict_rs_update_time_ms(_g1->pending_card_num());
- _predicted_rs_scan_time_ms =
- predict_rs_scan_time_ms(_predicted_cards_scanned);
- _predicted_object_copy_time_ms =
- predict_object_copy_time_ms(_predicted_bytes_to_copy);
- _predicted_constant_other_time_ms =
- predict_constant_other_time_ms();
- _predicted_young_other_time_ms =
- predict_young_other_time_ms(_recorded_young_regions);
- _predicted_non_young_other_time_ms =
- predict_non_young_other_time_ms(_recorded_non_young_regions);
-
- _predicted_pause_time_ms =
- _predicted_rs_update_time_ms +
- _predicted_rs_scan_time_ms +
- _predicted_object_copy_time_ms +
- _predicted_constant_other_time_ms +
- _predicted_young_other_time_ms +
- _predicted_non_young_other_time_ms;
-#endif // PREDICTIONS_VERBOSE
-}
-
void G1CollectorPolicy::check_if_region_is_too_expensive(double
predicted_time_ms) {
// I don't think we need to do this when in young GC mode since
@@ -2013,9 +1822,6 @@
}
}
-// </NEW PREDICTION>
-
-
void G1CollectorPolicy::update_recent_gc_times(double end_time_sec,
double elapsed_ms) {
_recent_gc_times_ms->add(elapsed_ms);
@@ -2023,99 +1829,6 @@
_prev_collection_pause_end_ms = end_time_sec * 1000.0;
}
-double G1CollectorPolicy::recent_avg_time_for_pauses_ms() {
- if (_recent_pause_times_ms->num() == 0) {
- return (double) MaxGCPauseMillis;
- }
- return _recent_pause_times_ms->avg();
-}
-
-double G1CollectorPolicy::recent_avg_time_for_rs_scan_ms() {
- if (_recent_rs_scan_times_ms->num() == 0) {
- return (double)MaxGCPauseMillis/3.0;
- }
- return _recent_rs_scan_times_ms->avg();
-}
-
-int G1CollectorPolicy::number_of_recent_gcs() {
- assert(_recent_rs_scan_times_ms->num() ==
- _recent_pause_times_ms->num(), "Sequence out of sync");
- assert(_recent_pause_times_ms->num() ==
- _recent_CS_bytes_used_before->num(), "Sequence out of sync");
- assert(_recent_CS_bytes_used_before->num() ==
- _recent_CS_bytes_surviving->num(), "Sequence out of sync");
-
- return _recent_pause_times_ms->num();
-}
-
-double G1CollectorPolicy::recent_avg_survival_fraction() {
- return recent_avg_survival_fraction_work(_recent_CS_bytes_surviving,
- _recent_CS_bytes_used_before);
-}
-
-double G1CollectorPolicy::last_survival_fraction() {
- return last_survival_fraction_work(_recent_CS_bytes_surviving,
- _recent_CS_bytes_used_before);
-}
-
-double
-G1CollectorPolicy::recent_avg_survival_fraction_work(TruncatedSeq* surviving,
- TruncatedSeq* before) {
- assert(surviving->num() == before->num(), "Sequence out of sync");
- if (before->sum() > 0.0) {
- double recent_survival_rate = surviving->sum() / before->sum();
- // We exempt parallel collection from this check because Alloc Buffer
- // fragmentation can produce negative collections.
- // Further, we're now always doing parallel collection. But I'm still
- // leaving this here as a placeholder for a more precise assertion later.
- // (DLD, 10/05.)
- assert((true || G1CollectedHeap::use_parallel_gc_threads()) ||
- _g1->evacuation_failed() ||
- recent_survival_rate <= 1.0, "Or bad frac");
- return recent_survival_rate;
- } else {
- return 1.0; // Be conservative.
- }
-}
-
-double
-G1CollectorPolicy::last_survival_fraction_work(TruncatedSeq* surviving,
- TruncatedSeq* before) {
- assert(surviving->num() == before->num(), "Sequence out of sync");
- if (surviving->num() > 0 && before->last() > 0.0) {
- double last_survival_rate = surviving->last() / before->last();
- // We exempt parallel collection from this check because Alloc Buffer
- // fragmentation can produce negative collections.
- // Further, we're now always doing parallel collection. But I'm still
- // leaving this here as a placeholder for a more precise assertion later.
- // (DLD, 10/05.)
- assert((true || G1CollectedHeap::use_parallel_gc_threads()) ||
- last_survival_rate <= 1.0, "Or bad frac");
- return last_survival_rate;
- } else {
- return 1.0;
- }
-}
-
-static const int survival_min_obs = 5;
-static double survival_min_obs_limits[] = { 0.9, 0.7, 0.5, 0.3, 0.1 };
-static const double min_survival_rate = 0.1;
-
-double
-G1CollectorPolicy::conservative_avg_survival_fraction_work(double avg,
- double latest) {
- double res = avg;
- if (number_of_recent_gcs() < survival_min_obs) {
- res = MAX2(res, survival_min_obs_limits[number_of_recent_gcs()]);
- }
- res = MAX2(res, latest);
- res = MAX2(res, min_survival_rate);
- // In the parallel case, LAB fragmentation can produce "negative
- // collections"; so can evac failure. Cap at 1.0
- res = MIN2(res, 1.0);
- return res;
-}
-
size_t G1CollectorPolicy::expansion_amount() {
double recent_gc_overhead = recent_avg_pause_time_ratio() * 100.0;
double threshold = _gc_overhead_perc;
@@ -2331,15 +2044,6 @@
print_summary_sd(0, buffer, &_all_aux_times_ms[i]);
}
}
-
- size_t all_region_num = _region_num_young + _region_num_tenured;
- gclog_or_tty->print_cr(" New Regions %8d, Young %8d (%6.2lf%%), "
- "Tenured %8d (%6.2lf%%)",
- all_region_num,
- _region_num_young,
- (double) _region_num_young / (double) all_region_num * 100.0,
- _region_num_tenured,
- (double) _region_num_tenured / (double) all_region_num * 100.0);
}
if (TraceGen1Time) {
if (_all_full_gc_times_ms->num() > 0) {
@@ -2361,14 +2065,6 @@
#endif // PRODUCT
}
-void G1CollectorPolicy::update_region_num(bool young) {
- if (young) {
- ++_region_num_young;
- } else {
- ++_region_num_tenured;
- }
-}
-
#ifndef PRODUCT
// for debugging, bit of a hack...
static char*
@@ -2617,6 +2313,7 @@
ParKnownGarbageHRClosure parKnownGarbageCl(_hrSorted, _chunk_size, i);
// Back to zero for the claim value.
_g1->heap_region_par_iterate_chunked(&parKnownGarbageCl, i,
+ _g1->workers()->active_workers(),
HeapRegion::InitialClaimValue);
jint regions_added = parKnownGarbageCl.marked_regions_added();
_hrSorted->incNumMarkedHeapRegions(regions_added);
@@ -2628,7 +2325,7 @@
};
void
-G1CollectorPolicy::record_concurrent_mark_cleanup_end() {
+G1CollectorPolicy::record_concurrent_mark_cleanup_end(int no_of_gc_threads) {
double start_sec;
if (G1PrintParCleanupStats) {
start_sec = os::elapsedTime();
@@ -2644,10 +2341,27 @@
if (G1CollectedHeap::use_parallel_gc_threads()) {
const size_t OverpartitionFactor = 4;
- const size_t MinWorkUnit = 8;
- const size_t WorkUnit =
- MAX2(_g1->n_regions() / (ParallelGCThreads * OverpartitionFactor),
- MinWorkUnit);
+ size_t WorkUnit;
+ // The use of MinChunkSize = 8 in the original code
+ // causes some assertion failures when the total number of
+ // region is less than 8. The code here tries to fix that.
+ // Should the original code also be fixed?
+ if (no_of_gc_threads > 0) {
+ const size_t MinWorkUnit =
+ MAX2(_g1->n_regions() / no_of_gc_threads, (size_t) 1U);
+ WorkUnit =
+ MAX2(_g1->n_regions() / (no_of_gc_threads * OverpartitionFactor),
+ MinWorkUnit);
+ } else {
+ assert(no_of_gc_threads > 0,
+ "The active gc workers should be greater than 0");
+ // In a product build do something reasonable to avoid a crash.
+ const size_t MinWorkUnit =
+ MAX2(_g1->n_regions() / ParallelGCThreads, (size_t) 1U);
+ WorkUnit =
+ MAX2(_g1->n_regions() / (ParallelGCThreads * OverpartitionFactor),
+ MinWorkUnit);
+ }
_collectionSetChooser->prepareForAddMarkedHeapRegionsPar(_g1->n_regions(),
WorkUnit);
ParKnownGarbageTask parKnownGarbageTask(_collectionSetChooser,
@@ -2682,8 +2396,7 @@
}
// Add the heap region at the head of the non-incremental collection set
-void G1CollectorPolicy::
-add_to_collection_set(HeapRegion* hr) {
+void G1CollectorPolicy::add_old_region_to_cset(HeapRegion* hr) {
assert(_inc_cset_build_state == Active, "Precondition");
assert(!hr->is_young(), "non-incremental add of young region");
@@ -2694,9 +2407,11 @@
hr->set_in_collection_set(true);
hr->set_next_in_collection_set(_collection_set);
_collection_set = hr;
- _collection_set_size++;
_collection_set_bytes_used_before += hr->used();
_g1->register_region_with_in_cset_fast_test(hr);
+ size_t rs_length = hr->rem_set()->occupied();
+ _recorded_rs_lengths += rs_length;
+ _old_cset_region_length += 1;
}
// Initialize the per-collection-set information
@@ -2705,16 +2420,11 @@
_inc_cset_head = NULL;
_inc_cset_tail = NULL;
- _inc_cset_size = 0;
_inc_cset_bytes_used_before = 0;
- _inc_cset_young_index = 0;
-
_inc_cset_max_finger = 0;
- _inc_cset_recorded_young_bytes = 0;
_inc_cset_recorded_rs_lengths = 0;
_inc_cset_predicted_elapsed_time_ms = 0;
- _inc_cset_predicted_bytes_to_copy = 0;
_inc_cset_build_state = Active;
}
@@ -2745,20 +2455,6 @@
// rset sampling code
hr->set_recorded_rs_length(rs_length);
hr->set_predicted_elapsed_time_ms(region_elapsed_time_ms);
-
-#if PREDICTIONS_VERBOSE
- size_t bytes_to_copy = predict_bytes_to_copy(hr);
- _inc_cset_predicted_bytes_to_copy += bytes_to_copy;
-
- // Record the number of bytes used in this region
- _inc_cset_recorded_young_bytes += used_bytes;
-
- // Cache the values we have added to the aggregated informtion
- // in the heap region in case we have to remove this region from
- // the incremental collection set, or it is updated by the
- // rset sampling code
- hr->set_predicted_bytes_to_copy(bytes_to_copy);
-#endif // PREDICTIONS_VERBOSE
}
void G1CollectorPolicy::remove_from_incremental_cset_info(HeapRegion* hr) {
@@ -2784,17 +2480,6 @@
// Clear the values cached in the heap region
hr->set_recorded_rs_length(0);
hr->set_predicted_elapsed_time_ms(0);
-
-#if PREDICTIONS_VERBOSE
- size_t old_predicted_bytes_to_copy = hr->predicted_bytes_to_copy();
- _inc_cset_predicted_bytes_to_copy -= old_predicted_bytes_to_copy;
-
- // Subtract the number of bytes used in this region
- _inc_cset_recorded_young_bytes -= used_bytes;
-
- // Clear the values cached in the heap region
- hr->set_predicted_bytes_to_copy(0);
-#endif // PREDICTIONS_VERBOSE
}
void G1CollectorPolicy::update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length) {
@@ -2806,8 +2491,8 @@
}
void G1CollectorPolicy::add_region_to_incremental_cset_common(HeapRegion* hr) {
- assert( hr->is_young(), "invariant");
- assert( hr->young_index_in_cset() == -1, "invariant" );
+ assert(hr->is_young(), "invariant");
+ assert(hr->young_index_in_cset() > -1, "should have already been set");
assert(_inc_cset_build_state == Active, "Precondition");
// We need to clear and set the cached recorded/cached collection set
@@ -2827,11 +2512,7 @@
hr->set_in_collection_set(true);
assert( hr->next_in_collection_set() == NULL, "invariant");
- _inc_cset_size++;
_g1->register_region_with_in_cset_fast_test(hr);
-
- hr->set_young_index_in_cset((int) _inc_cset_young_index);
- ++_inc_cset_young_index;
}
// Add the region at the RHS of the incremental cset
@@ -2899,8 +2580,6 @@
YoungList* young_list = _g1->young_list();
- start_recording_regions();
-
guarantee(target_pause_time_ms > 0.0,
err_msg("target_pause_time_ms = %1.6lf should be positive",
target_pause_time_ms));
@@ -2923,7 +2602,6 @@
if (time_remaining_ms < threshold) {
double prev_time_remaining_ms = time_remaining_ms;
time_remaining_ms = 0.50 * target_pause_time_ms;
- _within_target = false;
ergo_verbose3(ErgoCSetConstruction,
"adjust remaining time",
ergo_format_reason("remaining time lower than threshold")
@@ -2931,8 +2609,6 @@
ergo_format_ms("threshold")
ergo_format_ms("adjusted remaining time"),
prev_time_remaining_ms, threshold, time_remaining_ms);
- } else {
- _within_target = true;
}
size_t expansion_bytes = _g1->expansion_regions() * HeapRegion::GrainBytes;
@@ -2941,8 +2617,6 @@
double young_start_time_sec = os::elapsedTime();
_collection_set_bytes_used_before = 0;
- _collection_set_size = 0;
- _young_cset_length = 0;
_last_young_gc_full = full_young_gcs() ? true : false;
if (_last_young_gc_full) {
@@ -2955,9 +2629,9 @@
// pause are appended to the RHS of the young list, i.e.
// [Newly Young Regions ++ Survivors from last pause].
- size_t survivor_region_num = young_list->survivor_length();
- size_t eden_region_num = young_list->length() - survivor_region_num;
- size_t old_region_num = 0;
+ size_t survivor_region_length = young_list->survivor_length();
+ size_t eden_region_length = young_list->length() - survivor_region_length;
+ init_cset_region_lengths(eden_region_length, survivor_region_length);
hr = young_list->first_survivor_region();
while (hr != NULL) {
assert(hr->is_survivor(), "badly formed young list");
@@ -2971,9 +2645,7 @@
if (_g1->mark_in_progress())
_g1->concurrent_mark()->register_collection_set_finger(_inc_cset_max_finger);
- _young_cset_length = _inc_cset_young_index;
_collection_set = _inc_cset_head;
- _collection_set_size = _inc_cset_size;
_collection_set_bytes_used_before = _inc_cset_bytes_used_before;
time_remaining_ms -= _inc_cset_predicted_elapsed_time_ms;
predicted_pause_time_ms += _inc_cset_predicted_elapsed_time_ms;
@@ -2983,19 +2655,12 @@
ergo_format_region("eden")
ergo_format_region("survivors")
ergo_format_ms("predicted young region time"),
- eden_region_num, survivor_region_num,
+ eden_region_length, survivor_region_length,
_inc_cset_predicted_elapsed_time_ms);
// The number of recorded young regions is the incremental
// collection set's current size
- set_recorded_young_regions(_inc_cset_size);
set_recorded_rs_lengths(_inc_cset_recorded_rs_lengths);
- set_recorded_young_bytes(_inc_cset_recorded_young_bytes);
-#if PREDICTIONS_VERBOSE
- set_predicted_bytes_to_copy(_inc_cset_predicted_bytes_to_copy);
-#endif // PREDICTIONS_VERBOSE
-
- assert(_inc_cset_size == young_list->length(), "Invariant");
double young_end_time_sec = os::elapsedTime();
_recorded_young_cset_choice_time_ms =
@@ -3009,9 +2674,16 @@
NumberSeq seq;
double avg_prediction = 100000000000000000.0; // something very large
- size_t prev_collection_set_size = _collection_set_size;
double prev_predicted_pause_time_ms = predicted_pause_time_ms;
do {
+ // Note that add_old_region_to_cset() increments the
+ // _old_cset_region_length field and cset_region_length() returns the
+ // sum of _eden_cset_region_length, _survivor_cset_region_length, and
+ // _old_cset_region_length. So, as old regions are added to the
+ // CSet, _old_cset_region_length will be incremented and
+ // cset_region_length(), which is used below, will always reflect
+ // the the total number of regions added up to this point to the CSet.
+
hr = _collectionSetChooser->getNextMarkedRegion(time_remaining_ms,
avg_prediction);
if (hr != NULL) {
@@ -3019,8 +2691,7 @@
double predicted_time_ms = predict_region_elapsed_time_ms(hr, false);
time_remaining_ms -= predicted_time_ms;
predicted_pause_time_ms += predicted_time_ms;
- add_to_collection_set(hr);
- record_non_young_cset_region(hr);
+ add_old_region_to_cset(hr);
seq.add(predicted_time_ms);
avg_prediction = seq.avg() + seq.sd();
}
@@ -3041,13 +2712,13 @@
should_continue = false;
}
} else {
- if (_collection_set_size >= _young_list_fixed_length) {
+ if (cset_region_length() >= _young_list_fixed_length) {
ergo_verbose2(ErgoCSetConstruction,
"stop adding old regions to CSet",
ergo_format_reason("CSet length reached target")
ergo_format_region("CSet")
ergo_format_region("young target"),
- _collection_set_size, _young_list_fixed_length);
+ cset_region_length(), _young_list_fixed_length);
should_continue = false;
}
}
@@ -3055,23 +2726,21 @@
} while (should_continue);
if (!adaptive_young_list_length() &&
- _collection_set_size < _young_list_fixed_length) {
+ cset_region_length() < _young_list_fixed_length) {
ergo_verbose2(ErgoCSetConstruction,
"request partially-young GCs end",
ergo_format_reason("CSet length lower than target")
ergo_format_region("CSet")
ergo_format_region("young target"),
- _collection_set_size, _young_list_fixed_length);
+ cset_region_length(), _young_list_fixed_length);
_should_revert_to_full_young_gcs = true;
}
- old_region_num = _collection_set_size - prev_collection_set_size;
-
ergo_verbose2(ErgoCSetConstruction | ErgoHigh,
"add old regions to CSet",
ergo_format_region("old")
ergo_format_ms("predicted old region time"),
- old_region_num,
+ old_cset_region_length(),
predicted_pause_time_ms - prev_predicted_pause_time_ms);
}
@@ -3079,8 +2748,6 @@
count_CS_bytes_used();
- end_recording_regions();
-
ergo_verbose5(ErgoCSetConstruction,
"finish choosing CSet",
ergo_format_region("eden")
@@ -3088,7 +2755,8 @@
ergo_format_region("old")
ergo_format_ms("predicted pause time")
ergo_format_ms("target pause time"),
- eden_region_num, survivor_region_num, old_region_num,
+ eden_region_length, survivor_region_length,
+ old_cset_region_length(),
predicted_pause_time_ms, target_pause_time_ms);
double non_young_end_time_sec = os::elapsedTime();
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -85,13 +85,13 @@
class G1CollectorPolicy: public CollectorPolicy {
private:
- // The number of pauses during the execution.
- long _n_pauses;
-
// either equal to the number of parallel threads, if ParallelGCThreads
// has been set, or 1 otherwise
int _parallel_gc_threads;
+ // The number of GC threads currently active.
+ uintx _no_of_gc_threads;
+
enum SomePrivateConstants {
NumPrevPausesForHeuristics = 10
};
@@ -127,18 +127,9 @@
jlong _num_cc_clears; // number of times the card count cache has been cleared
#endif
- // Statistics for recent GC pauses. See below for how indexed.
- TruncatedSeq* _recent_rs_scan_times_ms;
-
// These exclude marking times.
- TruncatedSeq* _recent_pause_times_ms;
TruncatedSeq* _recent_gc_times_ms;
- TruncatedSeq* _recent_CS_bytes_used_before;
- TruncatedSeq* _recent_CS_bytes_surviving;
-
- TruncatedSeq* _recent_rs_sizes;
-
TruncatedSeq* _concurrent_mark_remark_times_ms;
TruncatedSeq* _concurrent_mark_cleanup_times_ms;
@@ -150,13 +141,6 @@
NumberSeq* _all_stop_world_times_ms;
NumberSeq* _all_yield_times_ms;
- size_t _region_num_young;
- size_t _region_num_tenured;
- size_t _prev_region_num_young;
- size_t _prev_region_num_tenured;
-
- NumberSeq* _all_mod_union_times_ms;
-
int _aux_num;
NumberSeq* _all_aux_times_ms;
double* _cur_aux_start_times_ms;
@@ -194,7 +178,6 @@
// locker is active. This should be >= _young_list_target_length;
size_t _young_list_max_length;
- size_t _young_cset_length;
bool _last_young_gc_full;
unsigned _full_young_pause_num;
@@ -217,8 +200,6 @@
return _during_marking;
}
- // <NEW PREDICTION>
-
private:
enum PredictionConstants {
TruncatedSeqLength = 10
@@ -240,47 +221,32 @@
TruncatedSeq* _non_young_other_cost_per_region_ms_seq;
TruncatedSeq* _pending_cards_seq;
- TruncatedSeq* _scanned_cards_seq;
TruncatedSeq* _rs_lengths_seq;
TruncatedSeq* _cost_per_byte_ms_during_cm_seq;
TruncatedSeq* _young_gc_eff_seq;
- TruncatedSeq* _max_conc_overhead_seq;
-
bool _using_new_ratio_calculations;
size_t _min_desired_young_length; // as set on the command line or default calculations
size_t _max_desired_young_length; // as set on the command line or default calculations
- size_t _recorded_young_regions;
- size_t _recorded_non_young_regions;
- size_t _recorded_region_num;
+ size_t _eden_cset_region_length;
+ size_t _survivor_cset_region_length;
+ size_t _old_cset_region_length;
+
+ void init_cset_region_lengths(size_t eden_cset_region_length,
+ size_t survivor_cset_region_length);
+
+ size_t eden_cset_region_length() { return _eden_cset_region_length; }
+ size_t survivor_cset_region_length() { return _survivor_cset_region_length; }
+ size_t old_cset_region_length() { return _old_cset_region_length; }
size_t _free_regions_at_end_of_collection;
size_t _recorded_rs_lengths;
size_t _max_rs_lengths;
- size_t _recorded_marked_bytes;
- size_t _recorded_young_bytes;
-
- size_t _predicted_pending_cards;
- size_t _predicted_cards_scanned;
- size_t _predicted_rs_lengths;
- size_t _predicted_bytes_to_copy;
-
- double _predicted_survival_ratio;
- double _predicted_rs_update_time_ms;
- double _predicted_rs_scan_time_ms;
- double _predicted_object_copy_time_ms;
- double _predicted_constant_other_time_ms;
- double _predicted_young_other_time_ms;
- double _predicted_non_young_other_time_ms;
- double _predicted_pause_time_ms;
-
- double _vtime_diff_ms;
-
double _recorded_young_free_cset_time_ms;
double _recorded_non_young_free_cset_time_ms;
@@ -317,21 +283,28 @@
double update_rs_processed_buffers,
double goal_ms);
+ uintx no_of_gc_threads() { return _no_of_gc_threads; }
+ void set_no_of_gc_threads(uintx v) { _no_of_gc_threads = v; }
+
double _pause_time_target_ms;
double _recorded_young_cset_choice_time_ms;
double _recorded_non_young_cset_choice_time_ms;
- bool _within_target;
size_t _pending_cards;
size_t _max_pending_cards;
public:
+ // Accessors
- void set_region_short_lived(HeapRegion* hr) {
+ void set_region_eden(HeapRegion* hr, int young_index_in_cset) {
+ hr->set_young();
hr->install_surv_rate_group(_short_lived_surv_rate_group);
+ hr->set_young_index_in_cset(young_index_in_cset);
}
- void set_region_survivors(HeapRegion* hr) {
+ void set_region_survivor(HeapRegion* hr, int young_index_in_cset) {
+ assert(hr->is_young() && hr->is_survivor(), "pre-condition");
hr->install_surv_rate_group(_survivor_surv_rate_group);
+ hr->set_young_index_in_cset(young_index_in_cset);
}
#ifndef PRODUCT
@@ -343,10 +316,6 @@
seq->davg() * confidence_factor(seq->num()));
}
- size_t young_cset_length() {
- return _young_cset_length;
- }
-
void record_max_rs_lengths(size_t rs_lengths) {
_max_rs_lengths = rs_lengths;
}
@@ -465,20 +434,12 @@
size_t predict_bytes_to_copy(HeapRegion* hr);
double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);
- void start_recording_regions();
- void record_cset_region_info(HeapRegion* hr, bool young);
- void record_non_young_cset_region(HeapRegion* hr);
+ void set_recorded_rs_lengths(size_t rs_lengths);
- void set_recorded_young_regions(size_t n_regions);
- void set_recorded_young_bytes(size_t bytes);
- void set_recorded_rs_lengths(size_t rs_lengths);
- void set_predicted_bytes_to_copy(size_t bytes);
-
- void end_recording_regions();
-
- void record_vtime_diff_ms(double vtime_diff_ms) {
- _vtime_diff_ms = vtime_diff_ms;
- }
+ size_t cset_region_length() { return young_cset_region_length() +
+ old_cset_region_length(); }
+ size_t young_cset_region_length() { return eden_cset_region_length() +
+ survivor_cset_region_length(); }
void record_young_free_cset_time_ms(double time_ms) {
_recorded_young_free_cset_time_ms = time_ms;
@@ -494,8 +455,6 @@
double predict_survivor_regions_evac_time();
- // </NEW PREDICTION>
-
void cset_regions_freed() {
bool propagate = _last_young_gc_full && !_in_marking_window;
_short_lived_surv_rate_group->all_surviving_words_recorded(propagate);
@@ -575,8 +534,6 @@
double sum_of_values (double* data);
double max_sum (double* data1, double* data2);
- int _last_satb_drain_processed_buffers;
- int _last_update_rs_processed_buffers;
double _last_pause_time_ms;
size_t _bytes_in_collection_set_before_gc;
@@ -596,10 +553,6 @@
// set at the start of the pause.
HeapRegion* _collection_set;
- // The number of regions in the collection set. Set from the incrementally
- // built collection set at the start of an evacuation pause.
- size_t _collection_set_size;
-
// The number of bytes in the collection set before the pause. Set from
// the incrementally built collection set at the start of an evacuation
// pause.
@@ -622,16 +575,6 @@
// The tail of the incrementally built collection set.
HeapRegion* _inc_cset_tail;
- // The number of regions in the incrementally built collection set.
- // Used to set _collection_set_size at the start of an evacuation
- // pause.
- size_t _inc_cset_size;
-
- // Used as the index in the surving young words structure
- // which tracks the amount of space, for each young region,
- // that survives the pause.
- size_t _inc_cset_young_index;
-
// The number of bytes in the incrementally built collection set.
// Used to set _collection_set_bytes_used_before at the start of
// an evacuation pause.
@@ -640,11 +583,6 @@
// Used to record the highest end of heap region in collection set
HeapWord* _inc_cset_max_finger;
- // The number of recorded used bytes in the young regions
- // of the collection set. This is the sum of the used() bytes
- // of retired young regions in the collection set.
- size_t _inc_cset_recorded_young_bytes;
-
// The RSet lengths recorded for regions in the collection set
// (updated by the periodic sampling of the regions in the
// young list/collection set).
@@ -655,68 +593,9 @@
// regions in the young list/collection set).
double _inc_cset_predicted_elapsed_time_ms;
- // The predicted bytes to copy for the regions in the collection
- // set (updated by the periodic sampling of the regions in the
- // young list/collection set).
- size_t _inc_cset_predicted_bytes_to_copy;
-
// Stash a pointer to the g1 heap.
G1CollectedHeap* _g1;
- // The average time in ms per collection pause, averaged over recent pauses.
- double recent_avg_time_for_pauses_ms();
-
- // The average time in ms for RS scanning, per pause, averaged
- // over recent pauses. (Note the RS scanning time for a pause
- // is itself an average of the RS scanning time for each worker
- // thread.)
- double recent_avg_time_for_rs_scan_ms();
-
- // The number of "recent" GCs recorded in the number sequences
- int number_of_recent_gcs();
-
- // The average survival ratio, computed by the total number of bytes
- // suriviving / total number of bytes before collection over the last
- // several recent pauses.
- double recent_avg_survival_fraction();
- // The survival fraction of the most recent pause; if there have been no
- // pauses, returns 1.0.
- double last_survival_fraction();
-
- // Returns a "conservative" estimate of the recent survival rate, i.e.,
- // one that may be higher than "recent_avg_survival_fraction".
- // This is conservative in several ways:
- // If there have been few pauses, it will assume a potential high
- // variance, and err on the side of caution.
- // It puts a lower bound (currently 0.1) on the value it will return.
- // To try to detect phase changes, if the most recent pause ("latest") has a
- // higher-than average ("avg") survival rate, it returns that rate.
- // "work" version is a utility function; young is restricted to young regions.
- double conservative_avg_survival_fraction_work(double avg,
- double latest);
-
- // The arguments are the two sequences that keep track of the number of bytes
- // surviving and the total number of bytes before collection, resp.,
- // over the last evereal recent pauses
- // Returns the survival rate for the category in the most recent pause.
- // If there have been no pauses, returns 1.0.
- double last_survival_fraction_work(TruncatedSeq* surviving,
- TruncatedSeq* before);
-
- // The arguments are the two sequences that keep track of the number of bytes
- // surviving and the total number of bytes before collection, resp.,
- // over the last several recent pauses
- // Returns the average survival ration over the last several recent pauses
- // If there have been no pauses, return 1.0
- double recent_avg_survival_fraction_work(TruncatedSeq* surviving,
- TruncatedSeq* before);
-
- double conservative_avg_survival_fraction() {
- double avg = recent_avg_survival_fraction();
- double latest = last_survival_fraction();
- return conservative_avg_survival_fraction_work(avg, latest);
- }
-
// The ratio of gc time to elapsed time, computed over recent pauses.
double _recent_avg_pause_time_ratio;
@@ -724,9 +603,6 @@
return _recent_avg_pause_time_ratio;
}
- // Number of pauses between concurrent marking.
- size_t _pauses_btwn_concurrent_mark;
-
// At the end of a pause we check the heap occupancy and we decide
// whether we will start a marking cycle during the next pause. If
// we decide that we want to do that, we will set this parameter to
@@ -849,9 +725,6 @@
GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; }
- // The number of collection pauses so far.
- long n_pauses() const { return _n_pauses; }
-
// Update the heuristic info to record a collection pause of the given
// start time, where the given number of bytes were used at the start.
// This may involve changing the desired size of a collection set.
@@ -864,19 +737,21 @@
void record_concurrent_mark_init_end(double
mark_init_elapsed_time_ms);
- void record_mark_closure_time(double mark_closure_time_ms);
+ void record_mark_closure_time(double mark_closure_time_ms) {
+ _mark_closure_time_ms = mark_closure_time_ms;
+ }
void record_concurrent_mark_remark_start();
void record_concurrent_mark_remark_end();
void record_concurrent_mark_cleanup_start();
- void record_concurrent_mark_cleanup_end();
+ void record_concurrent_mark_cleanup_end(int no_of_gc_threads);
void record_concurrent_mark_cleanup_completed();
void record_concurrent_pause();
void record_concurrent_pause_end();
- void record_collection_pause_end();
+ void record_collection_pause_end(int no_of_gc_threads);
void print_heap_transition();
// Record the fact that a full collection occurred.
@@ -900,15 +775,6 @@
_cur_satb_drain_time_ms = ms;
}
- void record_satb_drain_processed_buffers(int processed_buffers) {
- assert(_g1->mark_in_progress(), "shouldn't be here otherwise");
- _last_satb_drain_processed_buffers = processed_buffers;
- }
-
- void record_mod_union_time(double ms) {
- _all_mod_union_times_ms->add(ms);
- }
-
void record_update_rs_time(int thread, double ms) {
_par_last_update_rs_times_ms[thread] = ms;
}
@@ -1009,11 +875,8 @@
void clear_collection_set() { _collection_set = NULL; }
- // The number of elements in the current collection set.
- size_t collection_set_size() { return _collection_set_size; }
-
- // Add "hr" to the CS.
- void add_to_collection_set(HeapRegion* hr);
+ // Add old region "hr" to the CSet.
+ void add_old_region_to_cset(HeapRegion* hr);
// Incremental CSet Support
@@ -1023,9 +886,6 @@
// The tail of the incrementally built collection set.
HeapRegion* inc_set_tail() { return _inc_cset_tail; }
- // The number of elements in the incrementally built collection set.
- size_t inc_cset_size() { return _inc_cset_size; }
-
// Initialize incremental collection set info.
void start_incremental_cset_building();
@@ -1125,8 +985,6 @@
return _young_list_max_length;
}
- void update_region_num(bool young);
-
bool full_young_gcs() {
return _full_young_gcs;
}
--- a/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -209,29 +209,9 @@
size_t cards_looked_up() { return _cards;}
};
-// We want the parallel threads to start their scanning at
-// different collection set regions to avoid contention.
-// If we have:
-// n collection set regions
-// p threads
-// Then thread t will start at region t * floor (n/p)
-
-HeapRegion* G1RemSet::calculateStartRegion(int worker_i) {
- HeapRegion* result = _g1p->collection_set();
- if (ParallelGCThreads > 0) {
- size_t cs_size = _g1p->collection_set_size();
- int n_workers = _g1->workers()->total_workers();
- size_t cs_spans = cs_size / n_workers;
- size_t ind = cs_spans * worker_i;
- for (size_t i = 0; i < ind; i++)
- result = result->next_in_collection_set();
- }
- return result;
-}
-
void G1RemSet::scanRS(OopsInHeapRegionClosure* oc, int worker_i) {
double rs_time_start = os::elapsedTime();
- HeapRegion *startRegion = calculateStartRegion(worker_i);
+ HeapRegion *startRegion = _g1->start_cset_region_for_worker(worker_i);
ScanRSClosure scanRScl(oc, worker_i);
@@ -430,8 +410,10 @@
DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
dcqs.concatenate_logs();
- if (ParallelGCThreads > 0) {
- _seq_task->set_n_threads((int)n_workers());
+ if (G1CollectedHeap::use_parallel_gc_threads()) {
+ // Don't set the number of workers here. It will be set
+ // when the task is run
+ // _seq_task->set_n_termination((int)n_workers());
}
guarantee( _cards_scanned == NULL, "invariant" );
_cards_scanned = NEW_C_HEAP_ARRAY(size_t, n_workers());
@@ -578,7 +560,10 @@
void G1RemSet::scrub_par(BitMap* region_bm, BitMap* card_bm,
int worker_num, int claim_val) {
ScrubRSClosure scrub_cl(region_bm, card_bm);
- _g1->heap_region_par_iterate_chunked(&scrub_cl, worker_num, claim_val);
+ _g1->heap_region_par_iterate_chunked(&scrub_cl,
+ worker_num,
+ (int) n_workers(),
+ claim_val);
}
--- a/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -104,8 +104,6 @@
void scanRS(OopsInHeapRegionClosure* oc, int worker_i);
void updateRS(DirtyCardQueue* into_cset_dcq, int worker_i);
- HeapRegion* calculateStartRegion(int i);
-
CardTableModRefBS* ct_bs() { return _ct_bs; }
size_t cardsScanned() { return _total_cards_scanned; }
--- a/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -39,10 +39,6 @@
develop(intx, G1MarkingOverheadPercent, 0, \
"Overhead of concurrent marking") \
\
- \
- develop(intx, G1PolicyVerbose, 0, \
- "The verbosity level on G1 policy decisions") \
- \
develop(intx, G1MarkingVerboseLevel, 0, \
"Level (0-4) of verboseness of the marking code") \
\
@@ -58,9 +54,6 @@
develop(bool, G1TraceMarkStackOverflow, false, \
"If true, extra debugging code for CM restart for ovflw.") \
\
- develop(intx, G1PausesBtwnConcMark, -1, \
- "If positive, fixed number of pauses between conc markings") \
- \
diagnostic(bool, G1SummarizeConcMark, false, \
"Summarize concurrent mark info") \
\
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -367,12 +367,13 @@
static void setup_heap_region_size(uintx min_heap_size);
enum ClaimValues {
- InitialClaimValue = 0,
- FinalCountClaimValue = 1,
- NoteEndClaimValue = 2,
- ScrubRemSetClaimValue = 3,
- ParVerifyClaimValue = 4,
- RebuildRSClaimValue = 5
+ InitialClaimValue = 0,
+ FinalCountClaimValue = 1,
+ NoteEndClaimValue = 2,
+ ScrubRemSetClaimValue = 3,
+ ParVerifyClaimValue = 4,
+ RebuildRSClaimValue = 5,
+ CompleteMarkCSetClaimValue = 6
};
inline HeapWord* par_allocate_no_bot_updates(size_t word_size) {
@@ -416,7 +417,7 @@
void add_to_marked_bytes(size_t incr_bytes) {
_next_marked_bytes = _next_marked_bytes + incr_bytes;
- guarantee( _next_marked_bytes <= used(), "invariant" );
+ assert(_next_marked_bytes <= used(), "invariant" );
}
void zero_marked_bytes() {
--- a/hotspot/src/share/vm/gc_implementation/parNew/parCardTableModRefBS.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parNew/parCardTableModRefBS.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -33,6 +33,7 @@
#include "runtime/java.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/virtualspace.hpp"
+#include "runtime/vmThread.hpp"
void CardTableModRefBS::non_clean_card_iterate_parallel_work(Space* sp, MemRegion mr,
OopsInGenClosure* cl,
@@ -42,6 +43,11 @@
assert((n_threads == 1 && ParallelGCThreads == 0) ||
n_threads <= (int)ParallelGCThreads,
"# worker threads != # requested!");
+ assert(!Thread::current()->is_VM_thread() || (n_threads == 1), "There is only 1 VM thread");
+ assert(UseDynamicNumberOfGCThreads ||
+ !FLAG_IS_DEFAULT(ParallelGCThreads) ||
+ n_threads == (int)ParallelGCThreads,
+ "# worker threads != # requested!");
// Make sure the LNC array is valid for the space.
jbyte** lowest_non_clean;
uintptr_t lowest_non_clean_base_chunk_index;
@@ -52,6 +58,8 @@
int n_strides = n_threads * ParGCStridesPerThread;
SequentialSubTasksDone* pst = sp->par_seq_tasks();
+ // Sets the condition for completion of the subtask (how many threads
+ // need to finish in order to be done).
pst->set_n_threads(n_threads);
pst->set_n_tasks(n_strides);
--- a/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -305,7 +305,7 @@
inline ParScanThreadState& thread_state(int i);
- void reset(bool promotion_failed);
+ void reset(int active_workers, bool promotion_failed);
void flush();
#if TASKQUEUE_STATS
@@ -322,6 +322,9 @@
ParallelTaskTerminator& _term;
ParNewGeneration& _gen;
Generation& _next_gen;
+ public:
+ bool is_valid(int id) const { return id < length(); }
+ ParallelTaskTerminator* terminator() { return &_term; }
};
@@ -351,9 +354,9 @@
}
-void ParScanThreadStateSet::reset(bool promotion_failed)
+void ParScanThreadStateSet::reset(int active_threads, bool promotion_failed)
{
- _term.reset_for_reuse();
+ _term.reset_for_reuse(active_threads);
if (promotion_failed) {
for (int i = 0; i < length(); ++i) {
thread_state(i).print_and_clear_promotion_failure_size();
@@ -569,6 +572,24 @@
_state_set(state_set)
{}
+// Reset the terminator for the given number of
+// active threads.
+void ParNewGenTask::set_for_termination(int active_workers) {
+ _state_set->reset(active_workers, _gen->promotion_failed());
+ // Should the heap be passed in? There's only 1 for now so
+ // grab it instead.
+ GenCollectedHeap* gch = GenCollectedHeap::heap();
+ gch->set_n_termination(active_workers);
+}
+
+// The "i" passed to this method is the part of the work for
+// this thread. It is not the worker ID. The "i" is derived
+// from _started_workers which is incremented in internal_note_start()
+// called in GangWorker loop() and which is called under the
+// which is called under the protection of the gang monitor and is
+// called after a task is started. So "i" is based on
+// first-come-first-served.
+
void ParNewGenTask::work(int i) {
GenCollectedHeap* gch = GenCollectedHeap::heap();
// Since this is being done in a separate thread, need new resource
@@ -581,6 +602,8 @@
Generation* old_gen = gch->next_gen(_gen);
ParScanThreadState& par_scan_state = _state_set->thread_state(i);
+ assert(_state_set->is_valid(i), "Should not have been called");
+
par_scan_state.set_young_old_boundary(_young_old_boundary);
par_scan_state.start_strong_roots();
@@ -733,7 +756,9 @@
private:
virtual void work(int i);
-
+ virtual void set_for_termination(int active_workers) {
+ _state_set.terminator()->reset_for_reuse(active_workers);
+ }
private:
ParNewGeneration& _gen;
ProcessTask& _task;
@@ -789,18 +814,20 @@
GenCollectedHeap* gch = GenCollectedHeap::heap();
assert(gch->kind() == CollectedHeap::GenCollectedHeap,
"not a generational heap");
- WorkGang* workers = gch->workers();
+ FlexibleWorkGang* workers = gch->workers();
assert(workers != NULL, "Need parallel worker threads.");
+ _state_set.reset(workers->active_workers(), _generation.promotion_failed());
ParNewRefProcTaskProxy rp_task(task, _generation, *_generation.next_gen(),
_generation.reserved().end(), _state_set);
workers->run_task(&rp_task);
- _state_set.reset(_generation.promotion_failed());
+ _state_set.reset(0 /* bad value in debug if not reset */,
+ _generation.promotion_failed());
}
void ParNewRefProcTaskExecutor::execute(EnqueueTask& task)
{
GenCollectedHeap* gch = GenCollectedHeap::heap();
- WorkGang* workers = gch->workers();
+ FlexibleWorkGang* workers = gch->workers();
assert(workers != NULL, "Need parallel worker threads.");
ParNewRefEnqueueTaskProxy enq_task(task);
workers->run_task(&enq_task);
@@ -856,7 +883,13 @@
assert(gch->kind() == CollectedHeap::GenCollectedHeap,
"not a CMS generational heap");
AdaptiveSizePolicy* size_policy = gch->gen_policy()->size_policy();
- WorkGang* workers = gch->workers();
+ FlexibleWorkGang* workers = gch->workers();
+ assert(workers != NULL, "Need workgang for parallel work");
+ int active_workers =
+ AdaptiveSizePolicy::calc_active_workers(workers->total_workers(),
+ workers->active_workers(),
+ Threads::number_of_non_daemon_threads());
+ workers->set_active_workers(active_workers);
_next_gen = gch->next_gen(this);
assert(_next_gen != NULL,
"This must be the youngest gen, and not the only gen");
@@ -894,13 +927,19 @@
gch->save_marks();
assert(workers != NULL, "Need parallel worker threads.");
- ParallelTaskTerminator _term(workers->total_workers(), task_queues());
- ParScanThreadStateSet thread_state_set(workers->total_workers(),
+ int n_workers = active_workers;
+
+ // Set the correct parallelism (number of queues) in the reference processor
+ ref_processor()->set_active_mt_degree(n_workers);
+
+ // Always set the terminator for the active number of workers
+ // because only those workers go through the termination protocol.
+ ParallelTaskTerminator _term(n_workers, task_queues());
+ ParScanThreadStateSet thread_state_set(workers->active_workers(),
*to(), *this, *_next_gen, *task_queues(),
_overflow_stacks, desired_plab_sz(), _term);
ParNewGenTask tsk(this, _next_gen, reserved().end(), &thread_state_set);
- int n_workers = workers->total_workers();
gch->set_par_threads(n_workers);
gch->rem_set()->prepare_for_younger_refs_iterate(true);
// It turns out that even when we're using 1 thread, doing the work in a
@@ -914,7 +953,8 @@
GenCollectedHeap::StrongRootsScope srs(gch);
tsk.work(0);
}
- thread_state_set.reset(promotion_failed());
+ thread_state_set.reset(0 /* Bad value in debug if not reset */,
+ promotion_failed());
// Process (weak) reference objects found during scavenge.
ReferenceProcessor* rp = ref_processor();
@@ -927,6 +967,8 @@
EvacuateFollowersClosureGeneral evacuate_followers(gch, _level,
&scan_without_gc_barrier, &scan_with_gc_barrier);
rp->setup_policy(clear_all_soft_refs);
+ // Can the mt_degree be set later (at run_task() time would be best)?
+ rp->set_active_mt_degree(active_workers);
if (rp->processing_is_mt()) {
ParNewRefProcTaskExecutor task_executor(*this, thread_state_set);
rp->process_discovered_references(&is_alive, &keep_alive,
--- a/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -240,6 +240,10 @@
HeapWord* young_old_boundary() { return _young_old_boundary; }
void work(int i);
+
+ // Reset the terminator in ParScanThreadStateSet for
+ // "active_workers" threads.
+ virtual void set_for_termination(int active_workers);
};
class KeepAliveClosure: public DefNewGeneration::KeepAliveClosure {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -223,7 +223,8 @@
MutableSpace* sp,
HeapWord* space_top,
PSPromotionManager* pm,
- uint stripe_number) {
+ uint stripe_number,
+ uint stripe_total) {
int ssize = 128; // Naked constant! Work unit = 64k.
int dirty_card_count = 0;
@@ -231,7 +232,11 @@
jbyte* start_card = byte_for(sp->bottom());
jbyte* end_card = byte_for(sp_top - 1) + 1;
oop* last_scanned = NULL; // Prevent scanning objects more than once
- for (jbyte* slice = start_card; slice < end_card; slice += ssize*ParallelGCThreads) {
+ // The width of the stripe ssize*stripe_total must be
+ // consistent with the number of stripes so that the complete slice
+ // is covered.
+ size_t slice_width = ssize * stripe_total;
+ for (jbyte* slice = start_card; slice < end_card; slice += slice_width) {
jbyte* worker_start_card = slice + stripe_number * ssize;
if (worker_start_card >= end_card)
return; // We're done.
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -69,7 +69,8 @@
MutableSpace* sp,
HeapWord* space_top,
PSPromotionManager* pm,
- uint stripe_number);
+ uint stripe_number,
+ uint stripe_total);
// Verification
static void verify_all_young_refs_imprecise();
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -25,6 +25,7 @@
#include "precompiled.hpp"
#include "gc_implementation/parallelScavenge/gcTaskManager.hpp"
#include "gc_implementation/parallelScavenge/gcTaskThread.hpp"
+#include "gc_implementation/shared/adaptiveSizePolicy.hpp"
#include "memory/allocation.hpp"
#include "memory/allocation.inline.hpp"
#include "runtime/mutex.hpp"
@@ -181,6 +182,7 @@
}
set_insert_end(task);
increment_length();
+ verify_length();
if (TraceGCTaskQueue) {
print("after:");
}
@@ -192,7 +194,7 @@
tty->print_cr("[" INTPTR_FORMAT "]"
" GCTaskQueue::enqueue(list: "
INTPTR_FORMAT ")",
- this);
+ this, list);
print("before:");
list->print("list:");
}
@@ -211,14 +213,15 @@
list->remove_end()->set_older(insert_end());
insert_end()->set_newer(list->remove_end());
set_insert_end(list->insert_end());
+ set_length(length() + list_length);
// empty the argument list.
}
- set_length(length() + list_length);
list->initialize();
if (TraceGCTaskQueue) {
print("after:");
list->print("list:");
}
+ verify_length();
}
// Dequeue one task.
@@ -288,6 +291,7 @@
decrement_length();
assert(result->newer() == NULL, "shouldn't be on queue");
assert(result->older() == NULL, "shouldn't be on queue");
+ verify_length();
return result;
}
@@ -311,22 +315,40 @@
result->set_newer(NULL);
result->set_older(NULL);
decrement_length();
+ verify_length();
return result;
}
NOT_PRODUCT(
+// Count the elements in the queue and verify the length against
+// that count.
+void GCTaskQueue::verify_length() const {
+ uint count = 0;
+ for (GCTask* element = insert_end();
+ element != NULL;
+ element = element->older()) {
+
+ count++;
+ }
+ assert(count == length(), "Length does not match queue");
+}
+
void GCTaskQueue::print(const char* message) const {
tty->print_cr("[" INTPTR_FORMAT "] GCTaskQueue:"
" insert_end: " INTPTR_FORMAT
" remove_end: " INTPTR_FORMAT
+ " length: %d"
" %s",
- this, insert_end(), remove_end(), message);
+ this, insert_end(), remove_end(), length(), message);
+ uint count = 0;
for (GCTask* element = insert_end();
element != NULL;
element = element->older()) {
element->print(" ");
+ count++;
tty->cr();
}
+ tty->print("Total tasks: %d", count);
}
)
@@ -351,12 +373,16 @@
//
GCTaskManager::GCTaskManager(uint workers) :
_workers(workers),
+ _active_workers(0),
+ _idle_workers(0),
_ndc(NULL) {
initialize();
}
GCTaskManager::GCTaskManager(uint workers, NotifyDoneClosure* ndc) :
_workers(workers),
+ _active_workers(0),
+ _idle_workers(0),
_ndc(ndc) {
initialize();
}
@@ -373,6 +399,7 @@
GCTaskQueue* unsynchronized_queue = GCTaskQueue::create_on_c_heap();
_queue = SynchronizedGCTaskQueue::create(unsynchronized_queue, lock());
_noop_task = NoopGCTask::create_on_c_heap();
+ _idle_inactive_task = WaitForBarrierGCTask::create_on_c_heap();
_resource_flag = NEW_C_HEAP_ARRAY(bool, workers());
{
// Set up worker threads.
@@ -418,6 +445,8 @@
assert(queue()->is_empty(), "still have queued work");
NoopGCTask::destroy(_noop_task);
_noop_task = NULL;
+ WaitForBarrierGCTask::destroy(_idle_inactive_task);
+ _idle_inactive_task = NULL;
if (_thread != NULL) {
for (uint i = 0; i < workers(); i += 1) {
GCTaskThread::destroy(thread(i));
@@ -442,6 +471,86 @@
}
}
+void GCTaskManager::set_active_gang() {
+ _active_workers =
+ AdaptiveSizePolicy::calc_active_workers(workers(),
+ active_workers(),
+ Threads::number_of_non_daemon_threads());
+
+ assert(!all_workers_active() || active_workers() == ParallelGCThreads,
+ err_msg("all_workers_active() is incorrect: "
+ "active %d ParallelGCThreads %d", active_workers(),
+ ParallelGCThreads));
+ if (TraceDynamicGCThreads) {
+ gclog_or_tty->print_cr("GCTaskManager::set_active_gang(): "
+ "all_workers_active() %d workers %d "
+ "active %d ParallelGCThreads %d ",
+ all_workers_active(), workers(), active_workers(),
+ ParallelGCThreads);
+ }
+}
+
+// Create IdleGCTasks for inactive workers.
+// Creates tasks in a ResourceArea and assumes
+// an appropriate ResourceMark.
+void GCTaskManager::task_idle_workers() {
+ {
+ int more_inactive_workers = 0;
+ {
+ // Stop any idle tasks from exiting their IdleGCTask's
+ // and get the count for additional IdleGCTask's under
+ // the GCTaskManager's monitor so that the "more_inactive_workers"
+ // count is correct.
+ MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
+ _idle_inactive_task->set_should_wait(true);
+ // active_workers are a number being requested. idle_workers
+ // are the number currently idle. If all the workers are being
+ // requested to be active but some are already idle, reduce
+ // the number of active_workers to be consistent with the
+ // number of idle_workers. The idle_workers are stuck in
+ // idle tasks and will no longer be release (since a new GC
+ // is starting). Try later to release enough idle_workers
+ // to allow the desired number of active_workers.
+ more_inactive_workers =
+ workers() - active_workers() - idle_workers();
+ if (more_inactive_workers < 0) {
+ int reduced_active_workers = active_workers() + more_inactive_workers;
+ set_active_workers(reduced_active_workers);
+ more_inactive_workers = 0;
+ }
+ if (TraceDynamicGCThreads) {
+ gclog_or_tty->print_cr("JT: %d workers %d active %d "
+ "idle %d more %d",
+ Threads::number_of_non_daemon_threads(),
+ workers(),
+ active_workers(),
+ idle_workers(),
+ more_inactive_workers);
+ }
+ }
+ GCTaskQueue* q = GCTaskQueue::create();
+ for(uint i = 0; i < (uint) more_inactive_workers; i++) {
+ q->enqueue(IdleGCTask::create_on_c_heap());
+ increment_idle_workers();
+ }
+ assert(workers() == active_workers() + idle_workers(),
+ "total workers should equal active + inactive");
+ add_list(q);
+ // GCTaskQueue* q was created in a ResourceArea so a
+ // destroy() call is not needed.
+ }
+}
+
+void GCTaskManager::release_idle_workers() {
+ {
+ MutexLockerEx ml(monitor(),
+ Mutex::_no_safepoint_check_flag);
+ _idle_inactive_task->set_should_wait(false);
+ monitor()->notify_all();
+ // Release monitor
+ }
+}
+
void GCTaskManager::print_task_time_stamps() {
for(uint i=0; i<ParallelGCThreads; i++) {
GCTaskThread* t = thread(i);
@@ -510,6 +619,13 @@
// Release monitor().
}
+// GC workers wait in get_task() for new work to be added
+// to the GCTaskManager's queue. When new work is added,
+// a notify is sent to the waiting GC workers which then
+// compete to get tasks. If a GC worker wakes up and there
+// is no work on the queue, it is given a noop_task to execute
+// and then loops to find more work.
+
GCTask* GCTaskManager::get_task(uint which) {
GCTask* result = NULL;
// Grab the queue lock.
@@ -558,8 +674,10 @@
which, result, GCTask::Kind::to_string(result->kind()));
tty->print_cr(" %s", result->name());
}
- increment_busy_workers();
- increment_delivered_tasks();
+ if (!result->is_idle_task()) {
+ increment_busy_workers();
+ increment_delivered_tasks();
+ }
return result;
// Release monitor().
}
@@ -622,6 +740,7 @@
uint GCTaskManager::decrement_busy_workers() {
assert(queue()->own_lock(), "don't own the lock");
+ assert(_busy_workers > 0, "About to make a mistake");
_busy_workers -= 1;
return _busy_workers;
}
@@ -643,11 +762,28 @@
set_resource_flag(which, false);
}
+// "list" contains tasks that are ready to execute. Those
+// tasks are added to the GCTaskManager's queue of tasks and
+// then the GC workers are notified that there is new work to
+// do.
+//
+// Typically different types of tasks can be added to the "list".
+// For example in PSScavenge OldToYoungRootsTask, SerialOldToYoungRootsTask,
+// ScavengeRootsTask, and StealTask tasks are all added to the list
+// and then the GC workers are notified of new work. The tasks are
+// handed out in the order in which they are added to the list
+// (although execution is not necessarily in that order). As long
+// as any tasks are running the GCTaskManager will wait for execution
+// to complete. GC workers that execute a stealing task remain in
+// the stealing task until all stealing tasks have completed. The load
+// balancing afforded by the stealing tasks work best if the stealing
+// tasks are added last to the list.
+
void GCTaskManager::execute_and_wait(GCTaskQueue* list) {
WaitForBarrierGCTask* fin = WaitForBarrierGCTask::create();
list->enqueue(fin);
add_list(list);
- fin->wait_for();
+ fin->wait_for(true /* reset */);
// We have to release the barrier tasks!
WaitForBarrierGCTask::destroy(fin);
}
@@ -692,6 +828,72 @@
}
//
+// IdleGCTask
+//
+
+IdleGCTask* IdleGCTask::create() {
+ IdleGCTask* result = new IdleGCTask(false);
+ return result;
+}
+
+IdleGCTask* IdleGCTask::create_on_c_heap() {
+ IdleGCTask* result = new(ResourceObj::C_HEAP) IdleGCTask(true);
+ return result;
+}
+
+void IdleGCTask::do_it(GCTaskManager* manager, uint which) {
+ WaitForBarrierGCTask* wait_for_task = manager->idle_inactive_task();
+ if (TraceGCTaskManager) {
+ tty->print_cr("[" INTPTR_FORMAT "]"
+ " IdleGCTask:::do_it()"
+ " should_wait: %s",
+ this, wait_for_task->should_wait() ? "true" : "false");
+ }
+ MutexLockerEx ml(manager->monitor(), Mutex::_no_safepoint_check_flag);
+ if (TraceDynamicGCThreads) {
+ gclog_or_tty->print_cr("--- idle %d", which);
+ }
+ // Increment has to be done when the idle tasks are created.
+ // manager->increment_idle_workers();
+ manager->monitor()->notify_all();
+ while (wait_for_task->should_wait()) {
+ if (TraceGCTaskManager) {
+ tty->print_cr("[" INTPTR_FORMAT "]"
+ " IdleGCTask::do_it()"
+ " [" INTPTR_FORMAT "] (%s)->wait()",
+ this, manager->monitor(), manager->monitor()->name());
+ }
+ manager->monitor()->wait(Mutex::_no_safepoint_check_flag, 0);
+ }
+ manager->decrement_idle_workers();
+ if (TraceDynamicGCThreads) {
+ gclog_or_tty->print_cr("--- release %d", which);
+ }
+ if (TraceGCTaskManager) {
+ tty->print_cr("[" INTPTR_FORMAT "]"
+ " IdleGCTask::do_it() returns"
+ " should_wait: %s",
+ this, wait_for_task->should_wait() ? "true" : "false");
+ }
+ // Release monitor().
+}
+
+void IdleGCTask::destroy(IdleGCTask* that) {
+ if (that != NULL) {
+ that->destruct();
+ if (that->is_c_heap_obj()) {
+ FreeHeap(that);
+ }
+ }
+}
+
+void IdleGCTask::destruct() {
+ // This has to know it's superclass structure, just like the constructor.
+ this->GCTask::destruct();
+ // Nothing else to do.
+}
+
+//
// BarrierGCTask
//
@@ -768,7 +970,8 @@
}
WaitForBarrierGCTask* WaitForBarrierGCTask::create_on_c_heap() {
- WaitForBarrierGCTask* result = new WaitForBarrierGCTask(true);
+ WaitForBarrierGCTask* result =
+ new (ResourceObj::C_HEAP) WaitForBarrierGCTask(true);
return result;
}
@@ -849,7 +1052,7 @@
}
}
-void WaitForBarrierGCTask::wait_for() {
+void WaitForBarrierGCTask::wait_for(bool reset) {
if (TraceGCTaskManager) {
tty->print_cr("[" INTPTR_FORMAT "]"
" WaitForBarrierGCTask::wait_for()"
@@ -869,7 +1072,9 @@
monitor()->wait(Mutex::_no_safepoint_check_flag, 0);
}
// Reset the flag in case someone reuses this task.
- set_should_wait(true);
+ if (reset) {
+ set_should_wait(true);
+ }
if (TraceGCTaskManager) {
tty->print_cr("[" INTPTR_FORMAT "]"
" WaitForBarrierGCTask::wait_for() returns"
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -45,6 +45,7 @@
class ReleasingBarrierGCTask;
class NotifyingBarrierGCTask;
class WaitForBarrierGCTask;
+class IdleGCTask;
// A free list of Monitor*'s.
class MonitorSupply;
@@ -64,7 +65,8 @@
unknown_task,
ordinary_task,
barrier_task,
- noop_task
+ noop_task,
+ idle_task
};
static const char* to_string(kind value);
};
@@ -108,6 +110,9 @@
bool is_noop_task() const {
return kind()==Kind::noop_task;
}
+ bool is_idle_task() const {
+ return kind()==Kind::idle_task;
+ }
void print(const char* message) const PRODUCT_RETURN;
protected:
// Constructors: Only create subclasses.
@@ -153,6 +158,7 @@
assert(((insert_end() == NULL && remove_end() == NULL) ||
(insert_end() != NULL && remove_end() != NULL)),
"insert_end and remove_end don't match");
+ assert((insert_end() != NULL) || (_length == 0), "Not empty");
return insert_end() == NULL;
}
uint length() const {
@@ -204,6 +210,8 @@
GCTask* remove(); // Remove from remove end.
GCTask* remove(GCTask* task); // Remove from the middle.
void print(const char* message) const PRODUCT_RETURN;
+ // Debug support
+ void verify_length() const PRODUCT_RETURN;
};
// A GCTaskQueue that can be synchronized.
@@ -285,12 +293,76 @@
}
};
+// Dynamic number of GC threads
+//
+// GC threads wait in get_task() for work (i.e., a task) to perform.
+// When the number of GC threads was static, the number of tasks
+// created to do a job was equal to or greater than the maximum
+// number of GC threads (ParallelGCThreads). The job might be divided
+// into a number of tasks greater than the number of GC threads for
+// load balancing (i.e., over partitioning). The last task to be
+// executed by a GC thread in a job is a work stealing task. A
+// GC thread that gets a work stealing task continues to execute
+// that task until the job is done. In the static number of GC theads
+// case, tasks are added to a queue (FIFO). The work stealing tasks are
+// the last to be added. Once the tasks are added, the GC threads grab
+// a task and go. A single thread can do all the non-work stealing tasks
+// and then execute a work stealing and wait for all the other GC threads
+// to execute their work stealing task.
+// In the dynamic number of GC threads implementation, idle-tasks are
+// created to occupy the non-participating or "inactive" threads. An
+// idle-task makes the GC thread wait on a barrier that is part of the
+// GCTaskManager. The GC threads that have been "idled" in a IdleGCTask
+// are released once all the active GC threads have finished their work
+// stealing tasks. The GCTaskManager does not wait for all the "idled"
+// GC threads to resume execution. When those GC threads do resume
+// execution in the course of the thread scheduling, they call get_tasks()
+// as all the other GC threads do. Because all the "idled" threads are
+// not required to execute in order to finish a job, it is possible for
+// a GC thread to still be "idled" when the next job is started. Such
+// a thread stays "idled" for the next job. This can result in a new
+// job not having all the expected active workers. For example if on
+// job requests 4 active workers out of a total of 10 workers so the
+// remaining 6 are "idled", if the next job requests 6 active workers
+// but all 6 of the "idled" workers are still idle, then the next job
+// will only get 4 active workers.
+// The implementation for the parallel old compaction phase has an
+// added complication. In the static case parold partitions the chunks
+// ready to be filled into stacks, one for each GC thread. A GC thread
+// executing a draining task (drains the stack of ready chunks)
+// claims a stack according to it's id (the unique ordinal value assigned
+// to each GC thread). In the dynamic case not all GC threads will
+// actively participate so stacks with ready to fill chunks can only be
+// given to the active threads. An initial implementation chose stacks
+// number 1-n to get the ready chunks and required that GC threads
+// 1-n be the active workers. This was undesirable because it required
+// certain threads to participate. In the final implementation a
+// list of stacks equal in number to the active workers are filled
+// with ready chunks. GC threads that participate get a stack from
+// the task (DrainStacksCompactionTask), empty the stack, and then add it to a
+// recycling list at the end of the task. If the same GC thread gets
+// a second task, it gets a second stack to drain and returns it. The
+// stacks are added to a recycling list so that later stealing tasks
+// for this tasks can get a stack from the recycling list. Stealing tasks
+// use the stacks in its work in a way similar to the draining tasks.
+// A thread is not guaranteed to get anything but a stealing task and
+// a thread that only gets a stealing task has to get a stack. A failed
+// implementation tried to have the GC threads keep the stack they used
+// during a draining task for later use in the stealing task but that didn't
+// work because as noted a thread is not guaranteed to get a draining task.
+//
+// For PSScavenge and ParCompactionManager the GC threads are
+// held in the GCTaskThread** _thread array in GCTaskManager.
+
+
class GCTaskManager : public CHeapObj {
friend class ParCompactionManager;
friend class PSParallelCompact;
friend class PSScavenge;
friend class PSRefProcTaskExecutor;
friend class RefProcTaskExecutor;
+ friend class GCTaskThread;
+ friend class IdleGCTask;
private:
// Instance state.
NotifyDoneClosure* _ndc; // Notify on completion.
@@ -298,6 +370,7 @@
Monitor* _monitor; // Notification of changes.
SynchronizedGCTaskQueue* _queue; // Queue of tasks.
GCTaskThread** _thread; // Array of worker threads.
+ uint _active_workers; // Number of active workers.
uint _busy_workers; // Number of busy workers.
uint _blocking_worker; // The worker that's blocking.
bool* _resource_flag; // Array of flag per threads.
@@ -307,6 +380,8 @@
uint _emptied_queue; // Times we emptied the queue.
NoopGCTask* _noop_task; // The NoopGCTask instance.
uint _noop_tasks; // Count of noop tasks.
+ WaitForBarrierGCTask* _idle_inactive_task;// Task for inactive workers
+ volatile uint _idle_workers; // Number of idled workers
public:
// Factory create and destroy methods.
static GCTaskManager* create(uint workers) {
@@ -324,6 +399,9 @@
uint busy_workers() const {
return _busy_workers;
}
+ volatile uint idle_workers() const {
+ return _idle_workers;
+ }
// Pun between Monitor* and Mutex*
Monitor* monitor() const {
return _monitor;
@@ -331,6 +409,9 @@
Monitor * lock() const {
return _monitor;
}
+ WaitForBarrierGCTask* idle_inactive_task() {
+ return _idle_inactive_task;
+ }
// Methods.
// Add the argument task to be run.
void add_task(GCTask* task);
@@ -350,6 +431,10 @@
bool should_release_resources(uint which); // Predicate.
// Note the release of resources by the argument worker.
void note_release(uint which);
+ // Create IdleGCTasks for inactive workers and start workers
+ void task_idle_workers();
+ // Release the workers in IdleGCTasks
+ void release_idle_workers();
// Constants.
// A sentinel worker identifier.
static uint sentinel_worker() {
@@ -375,6 +460,15 @@
uint workers() const {
return _workers;
}
+ void set_active_workers(uint v) {
+ assert(v <= _workers, "Trying to set more workers active than there are");
+ _active_workers = MIN2(v, _workers);
+ assert(v != 0, "Trying to set active workers to 0");
+ _active_workers = MAX2(1U, _active_workers);
+ }
+ // Sets the number of threads that will be used in a collection
+ void set_active_gang();
+
NotifyDoneClosure* notify_done_closure() const {
return _ndc;
}
@@ -457,8 +551,21 @@
void reset_noop_tasks() {
_noop_tasks = 0;
}
+ void increment_idle_workers() {
+ _idle_workers++;
+ }
+ void decrement_idle_workers() {
+ _idle_workers--;
+ }
// Other methods.
void initialize();
+
+ public:
+ // Return true if all workers are currently active.
+ bool all_workers_active() { return workers() == active_workers(); }
+ uint active_workers() const {
+ return _active_workers;
+ }
};
//
@@ -475,6 +582,8 @@
static NoopGCTask* create();
static NoopGCTask* create_on_c_heap();
static void destroy(NoopGCTask* that);
+
+ virtual char* name() { return (char *)"noop task"; }
// Methods from GCTask.
void do_it(GCTaskManager* manager, uint which) {
// Nothing to do.
@@ -518,6 +627,8 @@
}
// Destructor-like method.
void destruct();
+
+ virtual char* name() { return (char *)"barrier task"; }
// Methods.
// Wait for this to be the only task running.
void do_it_internal(GCTaskManager* manager, uint which);
@@ -586,11 +697,13 @@
// the BarrierGCTask is done.
// This may cover many of the uses of NotifyingBarrierGCTasks.
class WaitForBarrierGCTask : public BarrierGCTask {
+ friend class GCTaskManager;
+ friend class IdleGCTask;
private:
// Instance state.
- Monitor* _monitor; // Guard and notify changes.
- bool _should_wait; // true=>wait, false=>proceed.
- const bool _is_c_heap_obj; // Was allocated on the heap.
+ Monitor* _monitor; // Guard and notify changes.
+ volatile bool _should_wait; // true=>wait, false=>proceed.
+ const bool _is_c_heap_obj; // Was allocated on the heap.
public:
virtual char* name() { return (char *) "waitfor-barrier-task"; }
@@ -600,7 +713,10 @@
static void destroy(WaitForBarrierGCTask* that);
// Methods.
void do_it(GCTaskManager* manager, uint which);
- void wait_for();
+ void wait_for(bool reset);
+ void set_should_wait(bool value) {
+ _should_wait = value;
+ }
protected:
// Constructor. Clients use factory, but there might be subclasses.
WaitForBarrierGCTask(bool on_c_heap);
@@ -613,12 +729,36 @@
bool should_wait() const {
return _should_wait;
}
- void set_should_wait(bool value) {
- _should_wait = value;
+ bool is_c_heap_obj() {
+ return _is_c_heap_obj;
}
+};
+
+// Task that is used to idle a GC task when fewer than
+// the maximum workers are wanted.
+class IdleGCTask : public GCTask {
+ const bool _is_c_heap_obj; // Was allocated on the heap.
+ public:
bool is_c_heap_obj() {
return _is_c_heap_obj;
}
+ // Factory create and destroy methods.
+ static IdleGCTask* create();
+ static IdleGCTask* create_on_c_heap();
+ static void destroy(IdleGCTask* that);
+
+ virtual char* name() { return (char *)"idle task"; }
+ // Methods from GCTask.
+ virtual void do_it(GCTaskManager* manager, uint which);
+protected:
+ // Constructor.
+ IdleGCTask(bool on_c_heap) :
+ GCTask(GCTask::Kind::idle_task),
+ _is_c_heap_obj(on_c_heap) {
+ // Nothing to do.
+ }
+ // Destructor-like method.
+ void destruct();
};
class MonitorSupply : public AllStatic {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskThread.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskThread.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -93,6 +93,11 @@
st->cr();
}
+// GC workers get tasks from the GCTaskManager and execute
+// them in this method. If there are no tasks to execute,
+// the GC workers wait in the GCTaskManager's get_task()
+// for tasks to be enqueued for execution.
+
void GCTaskThread::run() {
// Set up the thread for stack overflow support
this->record_stack_base_and_size();
@@ -124,7 +129,6 @@
for (; /* break */; ) {
// This will block until there is a task to be gotten.
GCTask* task = manager()->get_task(which());
-
// In case the update is costly
if (PrintGCTaskTimeStamps) {
timer.update();
@@ -134,18 +138,28 @@
char* name = task->name();
task->do_it(manager(), which());
- manager()->note_completion(which());
+
+ if (!task->is_idle_task()) {
+ manager()->note_completion(which());
- if (PrintGCTaskTimeStamps) {
- assert(_time_stamps != NULL, "Sanity (PrintGCTaskTimeStamps set late?)");
+ if (PrintGCTaskTimeStamps) {
+ assert(_time_stamps != NULL,
+ "Sanity (PrintGCTaskTimeStamps set late?)");
+
+ timer.update();
- timer.update();
-
- GCTaskTimeStamp* time_stamp = time_stamp_at(_time_stamp_index++);
+ GCTaskTimeStamp* time_stamp = time_stamp_at(_time_stamp_index++);
- time_stamp->set_name(name);
- time_stamp->set_entry_time(entry_time);
- time_stamp->set_exit_time(timer.ticks());
+ time_stamp->set_name(name);
+ time_stamp->set_entry_time(entry_time);
+ time_stamp->set_exit_time(timer.ticks());
+ }
+ } else {
+ // idle tasks complete outside the normal accounting
+ // so that a task can complete without waiting for idle tasks.
+ // They have to be terminated separately.
+ IdleGCTask::destroy((IdleGCTask*)task);
+ set_is_working(true);
}
// Check if we should release our inner resources.
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskThread.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskThread.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -35,6 +35,7 @@
class GCTaskManager;
class GCTaskThread : public WorkerThread {
+ friend class GCTaskManager;
private:
// Instance state.
GCTaskManager* _manager; // Manager for worker.
@@ -45,6 +46,8 @@
GCTaskTimeStamp* time_stamp_at(uint index);
+ bool _is_working; // True if participating in GC tasks
+
public:
// Factory create and destroy methods.
static GCTaskThread* create(GCTaskManager* manager,
@@ -84,6 +87,7 @@
uint processor_id() const {
return _processor_id;
}
+ void set_is_working(bool v) { _is_working = v; }
};
class GCTaskTimeStamp : public CHeapObj
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/pcTasks.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/pcTasks.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -152,15 +152,16 @@
{
ParallelScavengeHeap* heap = PSParallelCompact::gc_heap();
uint parallel_gc_threads = heap->gc_task_manager()->workers();
+ uint active_gc_threads = heap->gc_task_manager()->active_workers();
RegionTaskQueueSet* qset = ParCompactionManager::region_array();
- ParallelTaskTerminator terminator(parallel_gc_threads, qset);
+ ParallelTaskTerminator terminator(active_gc_threads, qset);
GCTaskQueue* q = GCTaskQueue::create();
for(uint i=0; i<parallel_gc_threads; i++) {
q->enqueue(new RefProcTaskProxy(task, i));
}
if (task.marks_oops_alive()) {
if (parallel_gc_threads>1) {
- for (uint j=0; j<parallel_gc_threads; j++) {
+ for (uint j=0; j<active_gc_threads; j++) {
q->enqueue(new StealMarkingTask(&terminator));
}
}
@@ -216,7 +217,6 @@
// StealRegionCompactionTask
//
-
StealRegionCompactionTask::StealRegionCompactionTask(ParallelTaskTerminator* t):
_terminator(t) {}
@@ -229,6 +229,32 @@
ParCompactionManager* cm =
ParCompactionManager::gc_thread_compaction_manager(which);
+
+ // If not all threads are active, get a draining stack
+ // from the list. Else, just use this threads draining stack.
+ uint which_stack_index;
+ bool use_all_workers = manager->all_workers_active();
+ if (use_all_workers) {
+ which_stack_index = which;
+ assert(manager->active_workers() == ParallelGCThreads,
+ err_msg("all_workers_active has been incorrectly set: "
+ " active %d ParallelGCThreads %d", manager->active_workers(),
+ ParallelGCThreads));
+ } else {
+ which_stack_index = ParCompactionManager::pop_recycled_stack_index();
+ }
+
+ cm->set_region_stack_index(which_stack_index);
+ cm->set_region_stack(ParCompactionManager::region_list(which_stack_index));
+ if (TraceDynamicGCThreads) {
+ gclog_or_tty->print_cr("StealRegionCompactionTask::do_it "
+ "region_stack_index %d region_stack = 0x%x "
+ " empty (%d) use all workers %d",
+ which_stack_index, ParCompactionManager::region_list(which_stack_index),
+ cm->region_stack()->is_empty(),
+ use_all_workers);
+ }
+
// Has to drain stacks first because there may be regions on
// preloaded onto the stack and this thread may never have
// done a draining task. Are the draining tasks needed?
@@ -285,6 +311,50 @@
ParCompactionManager* cm =
ParCompactionManager::gc_thread_compaction_manager(which);
+ uint which_stack_index;
+ bool use_all_workers = manager->all_workers_active();
+ if (use_all_workers) {
+ which_stack_index = which;
+ assert(manager->active_workers() == ParallelGCThreads,
+ err_msg("all_workers_active has been incorrectly set: "
+ " active %d ParallelGCThreads %d", manager->active_workers(),
+ ParallelGCThreads));
+ } else {
+ which_stack_index = stack_index();
+ }
+
+ cm->set_region_stack(ParCompactionManager::region_list(which_stack_index));
+ if (TraceDynamicGCThreads) {
+ gclog_or_tty->print_cr("DrainStacksCompactionTask::do_it which = %d "
+ "which_stack_index = %d/empty(%d) "
+ "use all workers %d",
+ which, which_stack_index,
+ cm->region_stack()->is_empty(),
+ use_all_workers);
+ }
+
+ cm->set_region_stack_index(which_stack_index);
+
// Process any regions already in the compaction managers stacks.
cm->drain_region_stacks();
+
+ assert(cm->region_stack()->is_empty(), "Not empty");
+
+ if (!use_all_workers) {
+ // Always give up the region stack.
+ assert(cm->region_stack() ==
+ ParCompactionManager::region_list(cm->region_stack_index()),
+ "region_stack and region_stack_index are inconsistent");
+ ParCompactionManager::push_recycled_stack_index(cm->region_stack_index());
+
+ if (TraceDynamicGCThreads) {
+ void* old_region_stack = (void*) cm->region_stack();
+ int old_region_stack_index = cm->region_stack_index();
+ gclog_or_tty->print_cr("Pushing region stack 0x%x/%d",
+ old_region_stack, old_region_stack_index);
+ }
+
+ cm->set_region_stack(NULL);
+ cm->set_region_stack_index((uint)max_uintx);
+ }
}
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psCompactionManager.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psCompactionManager.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -39,6 +39,9 @@
PSOldGen* ParCompactionManager::_old_gen = NULL;
ParCompactionManager** ParCompactionManager::_manager_array = NULL;
+
+RegionTaskQueue** ParCompactionManager::_region_list = NULL;
+
OopTaskQueueSet* ParCompactionManager::_stack_array = NULL;
ParCompactionManager::ObjArrayTaskQueueSet*
ParCompactionManager::_objarray_queues = NULL;
@@ -46,8 +49,14 @@
ParMarkBitMap* ParCompactionManager::_mark_bitmap = NULL;
RegionTaskQueueSet* ParCompactionManager::_region_array = NULL;
+uint* ParCompactionManager::_recycled_stack_index = NULL;
+int ParCompactionManager::_recycled_top = -1;
+int ParCompactionManager::_recycled_bottom = -1;
+
ParCompactionManager::ParCompactionManager() :
- _action(CopyAndUpdate) {
+ _action(CopyAndUpdate),
+ _region_stack(NULL),
+ _region_stack_index((uint)max_uintx) {
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
@@ -57,7 +66,10 @@
marking_stack()->initialize();
_objarray_stack.initialize();
- region_stack()->initialize();
+}
+
+ParCompactionManager::~ParCompactionManager() {
+ delete _recycled_stack_index;
}
void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
@@ -72,6 +84,19 @@
_manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1 );
guarantee(_manager_array != NULL, "Could not allocate manager_array");
+ _region_list = NEW_C_HEAP_ARRAY(RegionTaskQueue*,
+ parallel_gc_threads+1);
+ guarantee(_region_list != NULL, "Could not initialize promotion manager");
+
+ _recycled_stack_index = NEW_C_HEAP_ARRAY(uint, parallel_gc_threads);
+
+ // parallel_gc-threads + 1 to be consistent with the number of
+ // compaction managers.
+ for(uint i=0; i<parallel_gc_threads + 1; i++) {
+ _region_list[i] = new RegionTaskQueue();
+ region_list(i)->initialize();
+ }
+
_stack_array = new OopTaskQueueSet(parallel_gc_threads);
guarantee(_stack_array != NULL, "Could not allocate stack_array");
_objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
@@ -85,7 +110,7 @@
guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");
stack_array()->register_queue(i, _manager_array[i]->marking_stack());
_objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
- region_array()->register_queue(i, _manager_array[i]->region_stack());
+ region_array()->register_queue(i, region_list(i));
}
// The VMThread gets its own ParCompactionManager, which is not available
@@ -97,6 +122,29 @@
"Not initialized?");
}
+int ParCompactionManager::pop_recycled_stack_index() {
+ assert(_recycled_bottom <= _recycled_top, "list is empty");
+ // Get the next available index
+ if (_recycled_bottom < _recycled_top) {
+ uint cur, next, last;
+ do {
+ cur = _recycled_bottom;
+ next = cur + 1;
+ last = Atomic::cmpxchg(next, &_recycled_bottom, cur);
+ } while (cur != last);
+ return _recycled_stack_index[next];
+ } else {
+ return -1;
+ }
+}
+
+void ParCompactionManager::push_recycled_stack_index(uint v) {
+ // Get the next available index
+ int cur = Atomic::add(1, &_recycled_top);
+ _recycled_stack_index[cur] = v;
+ assert(_recycled_bottom <= _recycled_top, "list top and bottom are wrong");
+}
+
bool ParCompactionManager::should_update() {
assert(action() != NotValid, "Action is not set");
return (action() == ParCompactionManager::Update) ||
@@ -111,14 +159,13 @@
(action() == ParCompactionManager::UpdateAndCopy);
}
-bool ParCompactionManager::should_verify_only() {
- assert(action() != NotValid, "Action is not set");
- return action() == ParCompactionManager::VerifyUpdate;
+void ParCompactionManager::region_list_push(uint list_index,
+ size_t region_index) {
+ region_list(list_index)->push(region_index);
}
-bool ParCompactionManager::should_reset_only() {
- assert(action() != NotValid, "Action is not set");
- return action() == ParCompactionManager::ResetObjects;
+void ParCompactionManager::verify_region_list_empty(uint list_index) {
+ assert(region_list(list_index)->is_empty(), "Not empty");
}
ParCompactionManager*
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psCompactionManager.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psCompactionManager.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -48,6 +48,7 @@
friend class StealRegionCompactionTask;
friend class UpdateAndFillClosure;
friend class RefProcTaskExecutor;
+ friend class IdleGCTask;
public:
@@ -58,8 +59,6 @@
Copy,
UpdateAndCopy,
CopyAndUpdate,
- VerifyUpdate,
- ResetObjects,
NotValid
};
// ------------------------ End don't putback if not needed
@@ -85,7 +84,31 @@
// Is there a way to reuse the _marking_stack for the
// saving empty regions? For now just create a different
// type of TaskQueue.
- RegionTaskQueue _region_stack;
+ RegionTaskQueue* _region_stack;
+
+ static RegionTaskQueue** _region_list;
+ // Index in _region_list for current _region_stack.
+ uint _region_stack_index;
+
+ // Indexes of recycled region stacks/overflow stacks
+ // Stacks of regions to be compacted are embedded in the tasks doing
+ // the compaction. A thread that executes the task extracts the
+ // region stack and drains it. These threads keep these region
+ // stacks for use during compaction task stealing. If a thread
+ // gets a second draining task, it pushed its current region stack
+ // index into the array _recycled_stack_index and gets a new
+ // region stack from the task. A thread that is executing a
+ // compaction stealing task without ever having executing a
+ // draining task, will get a region stack from _recycled_stack_index.
+ //
+ // Array of indexes into the array of region stacks.
+ static uint* _recycled_stack_index;
+ // The index into _recycled_stack_index of the last region stack index
+ // pushed. If -1, there are no entries into _recycled_stack_index.
+ static int _recycled_top;
+ // The index into _recycled_stack_index of the last region stack index
+ // popped. If -1, there has not been any entry popped.
+ static int _recycled_bottom;
Stack<Klass*> _revisit_klass_stack;
Stack<DataLayout*> _revisit_mdo_stack;
@@ -104,7 +127,6 @@
// Array of tasks. Needed by the ParallelTaskTerminator.
static RegionTaskQueueSet* region_array() { return _region_array; }
OverflowTaskQueue<oop>* marking_stack() { return &_marking_stack; }
- RegionTaskQueue* region_stack() { return &_region_stack; }
// Pushes onto the marking stack. If the marking stack is full,
// pushes onto the overflow stack.
@@ -116,10 +138,33 @@
Action action() { return _action; }
void set_action(Action v) { _action = v; }
+ RegionTaskQueue* region_stack() { return _region_stack; }
+ void set_region_stack(RegionTaskQueue* v) { _region_stack = v; }
+
inline static ParCompactionManager* manager_array(int index);
+ inline static RegionTaskQueue* region_list(int index) {
+ return _region_list[index];
+ }
+
+ uint region_stack_index() { return _region_stack_index; }
+ void set_region_stack_index(uint v) { _region_stack_index = v; }
+
+ // Pop and push unique reusable stack index
+ static int pop_recycled_stack_index();
+ static void push_recycled_stack_index(uint v);
+ static void reset_recycled_stack_index() {
+ _recycled_bottom = _recycled_top = -1;
+ }
+
ParCompactionManager();
+ ~ParCompactionManager();
+ // Pushes onto the region stack at the given index. If the
+ // region stack is full,
+ // pushes onto the region overflow stack.
+ static void region_list_push(uint stack_index, size_t region_index);
+ static void verify_region_list_empty(uint stack_index);
ParMarkBitMap* mark_bitmap() { return _mark_bitmap; }
// Take actions in preparation for a compaction.
@@ -129,8 +174,6 @@
bool should_update();
bool should_copy();
- bool should_verify_only();
- bool should_reset_only();
Stack<Klass*>* revisit_klass_stack() { return &_revisit_klass_stack; }
Stack<DataLayout*>* revisit_mdo_stack() { return &_revisit_mdo_stack; }
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweepDecorator.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweepDecorator.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -96,7 +96,8 @@
* by the MarkSweepAlwaysCompactCount parameter. This is a significant
* performance improvement!
*/
- bool skip_dead = ((PSMarkSweep::total_invocations() % MarkSweepAlwaysCompactCount) != 0);
+ bool skip_dead = (MarkSweepAlwaysCompactCount < 1)
+ || ((PSMarkSweep::total_invocations() % MarkSweepAlwaysCompactCount) != 0);
size_t allowed_deadspace = 0;
if (skip_dead) {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -2045,6 +2045,11 @@
ResourceMark rm;
HandleMark hm;
+ // Set the number of GC threads to be used in this collection
+ gc_task_manager()->set_active_gang();
+ gc_task_manager()->task_idle_workers();
+ heap->set_par_threads(gc_task_manager()->active_workers());
+
const bool is_system_gc = gc_cause == GCCause::_java_lang_system_gc;
// This is useful for debugging but don't change the output the
@@ -2197,6 +2202,7 @@
// Track memory usage and detect low memory
MemoryService::track_memory_usage();
heap->update_counters();
+ gc_task_manager()->release_idle_workers();
}
#ifdef ASSERT
@@ -2204,7 +2210,7 @@
ParCompactionManager* const cm =
ParCompactionManager::manager_array(int(i));
assert(cm->marking_stack()->is_empty(), "should be empty");
- assert(cm->region_stack()->is_empty(), "should be empty");
+ assert(ParCompactionManager::region_list(int(i))->is_empty(), "should be empty");
assert(cm->revisit_klass_stack()->is_empty(), "should be empty");
}
#endif // ASSERT
@@ -2351,8 +2357,9 @@
ParallelScavengeHeap* heap = gc_heap();
uint parallel_gc_threads = heap->gc_task_manager()->workers();
+ uint active_gc_threads = heap->gc_task_manager()->active_workers();
TaskQueueSetSuper* qset = ParCompactionManager::region_array();
- ParallelTaskTerminator terminator(parallel_gc_threads, qset);
+ ParallelTaskTerminator terminator(active_gc_threads, qset);
PSParallelCompact::MarkAndPushClosure mark_and_push_closure(cm);
PSParallelCompact::FollowStackClosure follow_stack_closure(cm);
@@ -2374,21 +2381,13 @@
q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::jvmti));
q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::code_cache));
- if (parallel_gc_threads > 1) {
- for (uint j = 0; j < parallel_gc_threads; j++) {
+ if (active_gc_threads > 1) {
+ for (uint j = 0; j < active_gc_threads; j++) {
q->enqueue(new StealMarkingTask(&terminator));
}
}
- WaitForBarrierGCTask* fin = WaitForBarrierGCTask::create();
- q->enqueue(fin);
-
- gc_task_manager()->add_list(q);
-
- fin->wait_for();
-
- // We have to release the barrier tasks!
- WaitForBarrierGCTask::destroy(fin);
+ gc_task_manager()->execute_and_wait(q);
}
// Process reference objects found during marking
@@ -2483,10 +2482,22 @@
{
TraceTime tm("drain task setup", print_phases(), true, gclog_or_tty);
- const unsigned int task_count = MAX2(parallel_gc_threads, 1U);
- for (unsigned int j = 0; j < task_count; j++) {
+ // Find the threads that are active
+ unsigned int which = 0;
+
+ const uint task_count = MAX2(parallel_gc_threads, 1U);
+ for (uint j = 0; j < task_count; j++) {
q->enqueue(new DrainStacksCompactionTask(j));
+ ParCompactionManager::verify_region_list_empty(j);
+ // Set the region stacks variables to "no" region stack values
+ // so that they will be recognized and needing a region stack
+ // in the stealing tasks if they do not get one by executing
+ // a draining stack.
+ ParCompactionManager* cm = ParCompactionManager::manager_array(j);
+ cm->set_region_stack(NULL);
+ cm->set_region_stack_index((uint)max_uintx);
}
+ ParCompactionManager::reset_recycled_stack_index();
// Find all regions that are available (can be filled immediately) and
// distribute them to the thread stacks. The iteration is done in reverse
@@ -2495,8 +2506,10 @@
const ParallelCompactData& sd = PSParallelCompact::summary_data();
size_t fillable_regions = 0; // A count for diagnostic purposes.
- unsigned int which = 0; // The worker thread number.
-
+ // A region index which corresponds to the tasks created above.
+ // "which" must be 0 <= which < task_count
+
+ which = 0;
for (unsigned int id = to_space_id; id > perm_space_id; --id) {
SpaceInfo* const space_info = _space_info + id;
MutableSpace* const space = space_info->space();
@@ -2509,8 +2522,7 @@
for (size_t cur = end_region - 1; cur >= beg_region; --cur) {
if (sd.region(cur)->claim_unsafe()) {
- ParCompactionManager* cm = ParCompactionManager::manager_array(which);
- cm->push_region(cur);
+ ParCompactionManager::region_list_push(which, cur);
if (TraceParallelOldGCCompactionPhase && Verbose) {
const size_t count_mod_8 = fillable_regions & 7;
@@ -2521,8 +2533,10 @@
NOT_PRODUCT(++fillable_regions;)
- // Assign regions to threads in round-robin fashion.
+ // Assign regions to tasks in round-robin fashion.
if (++which == task_count) {
+ assert(which <= parallel_gc_threads,
+ "Inconsistent number of workers");
which = 0;
}
}
@@ -2642,26 +2656,19 @@
PSOldGen* old_gen = heap->old_gen();
old_gen->start_array()->reset();
uint parallel_gc_threads = heap->gc_task_manager()->workers();
+ uint active_gc_threads = heap->gc_task_manager()->active_workers();
TaskQueueSetSuper* qset = ParCompactionManager::region_array();
- ParallelTaskTerminator terminator(parallel_gc_threads, qset);
+ ParallelTaskTerminator terminator(active_gc_threads, qset);
GCTaskQueue* q = GCTaskQueue::create();
- enqueue_region_draining_tasks(q, parallel_gc_threads);
- enqueue_dense_prefix_tasks(q, parallel_gc_threads);
- enqueue_region_stealing_tasks(q, &terminator, parallel_gc_threads);
+ enqueue_region_draining_tasks(q, active_gc_threads);
+ enqueue_dense_prefix_tasks(q, active_gc_threads);
+ enqueue_region_stealing_tasks(q, &terminator, active_gc_threads);
{
TraceTime tm_pc("par compact", print_phases(), true, gclog_or_tty);
- WaitForBarrierGCTask* fin = WaitForBarrierGCTask::create();
- q->enqueue(fin);
-
- gc_task_manager()->add_list(q);
-
- fin->wait_for();
-
- // We have to release the barrier tasks!
- WaitForBarrierGCTask::destroy(fin);
+ gc_task_manager()->execute_and_wait(q);
#ifdef ASSERT
// Verify that all regions have been processed before the deferred updates.
@@ -2729,6 +2736,9 @@
PSParallelCompact::follow_weak_klass_links() {
// All klasses on the revisit stack are marked at this point.
// Update and follow all subklass, sibling and implementor links.
+ // Check all the stacks here even if not all the workers are active.
+ // There is no accounting which indicates which stacks might have
+ // contents to be followed.
if (PrintRevisitStats) {
gclog_or_tty->print_cr("#classes in system dictionary = %d",
SystemDictionary::number_of_classes());
@@ -3360,20 +3370,7 @@
HeapWord* beg_addr = sp->bottom();
HeapWord* end_addr = sp->top();
-#ifdef ASSERT
assert(beg_addr <= dp_addr && dp_addr <= end_addr, "bad dense prefix");
- if (cm->should_verify_only()) {
- VerifyUpdateClosure verify_update(cm, sp);
- bitmap->iterate(&verify_update, beg_addr, end_addr);
- return;
- }
-
- if (cm->should_reset_only()) {
- ResetObjectsClosure reset_objects(cm);
- bitmap->iterate(&reset_objects, beg_addr, end_addr);
- return;
- }
-#endif
const size_t beg_region = sd.addr_to_region_idx(beg_addr);
const size_t dp_region = sd.addr_to_region_idx(dp_addr);
@@ -3492,35 +3489,6 @@
return ParMarkBitMap::incomplete;
}
-// Verify the new location using the forwarding pointer
-// from MarkSweep::mark_sweep_phase2(). Set the mark_word
-// to the initial value.
-ParMarkBitMapClosure::IterationStatus
-PSParallelCompact::VerifyUpdateClosure::do_addr(HeapWord* addr, size_t words) {
- // The second arg (words) is not used.
- oop obj = (oop) addr;
- HeapWord* forwarding_ptr = (HeapWord*) obj->mark()->decode_pointer();
- HeapWord* new_pointer = summary_data().calc_new_pointer(obj);
- if (forwarding_ptr == NULL) {
- // The object is dead or not moving.
- assert(bitmap()->is_unmarked(obj) || (new_pointer == (HeapWord*) obj),
- "Object liveness is wrong.");
- return ParMarkBitMap::incomplete;
- }
- assert(HeapMaximumCompactionInterval > 1 || MarkSweepAlwaysCompactCount > 1 ||
- forwarding_ptr == new_pointer, "new location is incorrect");
- return ParMarkBitMap::incomplete;
-}
-
-// Reset objects modified for debug checking.
-ParMarkBitMapClosure::IterationStatus
-PSParallelCompact::ResetObjectsClosure::do_addr(HeapWord* addr, size_t words) {
- // The second arg (words) is not used.
- oop obj = (oop) addr;
- obj->init_mark();
- return ParMarkBitMap::incomplete;
-}
-
// Prepare for compaction. This method is executed once
// (i.e., by a single thread) before compaction.
// Save the updated location of the intArrayKlassObj for
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -832,31 +832,6 @@
virtual void do_code_blob(CodeBlob* cb) const { }
};
- // Closure for verifying update of pointers. Does not
- // have any side effects.
- class VerifyUpdateClosure: public ParMarkBitMapClosure {
- const MutableSpace* _space; // Is this ever used?
-
- public:
- VerifyUpdateClosure(ParCompactionManager* cm, const MutableSpace* sp) :
- ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm), _space(sp)
- { }
-
- virtual IterationStatus do_addr(HeapWord* addr, size_t words);
-
- const MutableSpace* space() { return _space; }
- };
-
- // Closure for updating objects altered for debug checking
- class ResetObjectsClosure: public ParMarkBitMapClosure {
- public:
- ResetObjectsClosure(ParCompactionManager* cm):
- ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm)
- { }
-
- virtual IterationStatus do_addr(HeapWord* addr, size_t words);
- };
-
friend class KeepAliveClosure;
friend class FollowStackClosure;
friend class AdjustPointerClosure;
@@ -1183,10 +1158,6 @@
// Update the deferred objects in the space.
static void update_deferred_objects(ParCompactionManager* cm, SpaceId id);
- // Mark pointer and follow contents.
- template <class T>
- static inline void mark_and_follow(ParCompactionManager* cm, T* p);
-
static ParMarkBitMap* mark_bitmap() { return &_mark_bitmap; }
static ParallelCompactData& summary_data() { return _summary_data; }
@@ -1283,20 +1254,6 @@
}
template <class T>
-inline void PSParallelCompact::mark_and_follow(ParCompactionManager* cm,
- T* p) {
- T heap_oop = oopDesc::load_heap_oop(p);
- if (!oopDesc::is_null(heap_oop)) {
- oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
- if (mark_bitmap()->is_unmarked(obj)) {
- if (mark_obj(obj)) {
- obj->follow_contents(cm);
- }
- }
- }
-}
-
-template <class T>
inline void PSParallelCompact::mark_and_push(ParCompactionManager* cm, T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -181,28 +181,29 @@
void PSRefProcTaskExecutor::execute(ProcessTask& task)
{
GCTaskQueue* q = GCTaskQueue::create();
- for(uint i=0; i<ParallelGCThreads; i++) {
+ GCTaskManager* manager = ParallelScavengeHeap::gc_task_manager();
+ for(uint i=0; i < manager->active_workers(); i++) {
q->enqueue(new PSRefProcTaskProxy(task, i));
}
- ParallelTaskTerminator terminator(
- ParallelScavengeHeap::gc_task_manager()->workers(),
+ ParallelTaskTerminator terminator(manager->active_workers(),
(TaskQueueSetSuper*) PSPromotionManager::stack_array_depth());
- if (task.marks_oops_alive() && ParallelGCThreads > 1) {
- for (uint j=0; j<ParallelGCThreads; j++) {
+ if (task.marks_oops_alive() && manager->active_workers() > 1) {
+ for (uint j = 0; j < manager->active_workers(); j++) {
q->enqueue(new StealTask(&terminator));
}
}
- ParallelScavengeHeap::gc_task_manager()->execute_and_wait(q);
+ manager->execute_and_wait(q);
}
void PSRefProcTaskExecutor::execute(EnqueueTask& task)
{
GCTaskQueue* q = GCTaskQueue::create();
- for(uint i=0; i<ParallelGCThreads; i++) {
+ GCTaskManager* manager = ParallelScavengeHeap::gc_task_manager();
+ for(uint i=0; i < manager->active_workers(); i++) {
q->enqueue(new PSRefEnqueueTaskProxy(task, i));
}
- ParallelScavengeHeap::gc_task_manager()->execute_and_wait(q);
+ manager->execute_and_wait(q);
}
// This method contains all heap specific policy for invoking scavenge.
@@ -375,6 +376,14 @@
// Release all previously held resources
gc_task_manager()->release_all_resources();
+ // Set the number of GC threads to be used in this collection
+ gc_task_manager()->set_active_gang();
+ gc_task_manager()->task_idle_workers();
+ // Get the active number of workers here and use that value
+ // throughout the methods.
+ uint active_workers = gc_task_manager()->active_workers();
+ heap->set_par_threads(active_workers);
+
PSPromotionManager::pre_scavenge();
// We'll use the promotion manager again later.
@@ -385,8 +394,9 @@
GCTaskQueue* q = GCTaskQueue::create();
- for(uint i=0; i<ParallelGCThreads; i++) {
- q->enqueue(new OldToYoungRootsTask(old_gen, old_top, i));
+ uint stripe_total = active_workers;
+ for(uint i=0; i < stripe_total; i++) {
+ q->enqueue(new OldToYoungRootsTask(old_gen, old_top, i, stripe_total));
}
q->enqueue(new SerialOldToYoungRootsTask(perm_gen, perm_top));
@@ -403,10 +413,10 @@
q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::code_cache));
ParallelTaskTerminator terminator(
- gc_task_manager()->workers(),
+ active_workers,
(TaskQueueSetSuper*) promotion_manager->stack_array_depth());
- if (ParallelGCThreads>1) {
- for (uint j=0; j<ParallelGCThreads; j++) {
+ if (active_workers > 1) {
+ for (uint j = 0; j < active_workers; j++) {
q->enqueue(new StealTask(&terminator));
}
}
@@ -419,6 +429,7 @@
// Process reference objects discovered during scavenge
{
reference_processor()->setup_policy(false); // not always_clear
+ reference_processor()->set_active_mt_degree(active_workers);
PSKeepAliveClosure keep_alive(promotion_manager);
PSEvacuateFollowersClosure evac_followers(promotion_manager);
if (reference_processor()->processing_is_mt()) {
@@ -622,6 +633,8 @@
// Track memory usage and detect low memory
MemoryService::track_memory_usage();
heap->update_counters();
+
+ gc_task_manager()->release_idle_workers();
}
if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
@@ -804,6 +817,7 @@
// Initialize ref handling object for scavenging.
MemRegion mr = young_gen->reserved();
+
_ref_processor =
new ReferenceProcessor(mr, // span
ParallelRefProcEnabled && (ParallelGCThreads > 1), // mt processing
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psTasks.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psTasks.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -202,7 +202,8 @@
_gen->object_space(),
_gen_top,
pm,
- _stripe_number);
+ _stripe_number,
+ _stripe_total);
// Do the real work
pm->drain_stacks(false);
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psTasks.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psTasks.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -135,16 +135,63 @@
// OldToYoungRootsTask
//
// This task is used to scan old to young roots in parallel
+//
+// A GC thread executing this tasks divides the generation (old gen)
+// into slices and takes a stripe in the slice as its part of the
+// work.
+//
+// +===============+ slice 0
+// | stripe 0 |
+// +---------------+
+// | stripe 1 |
+// +---------------+
+// | stripe 2 |
+// +---------------+
+// | stripe 3 |
+// +===============+ slice 1
+// | stripe 0 |
+// +---------------+
+// | stripe 1 |
+// +---------------+
+// | stripe 2 |
+// +---------------+
+// | stripe 3 |
+// +===============+ slice 2
+// ...
+//
+// A task is created for each stripe. In this case there are 4 tasks
+// created. A GC thread first works on its stripe within slice 0
+// and then moves to its stripe in the next slice until all stripes
+// exceed the top of the generation. Note that having fewer GC threads
+// than stripes works because all the tasks are executed so all stripes
+// will be covered. In this example if 4 tasks have been created to cover
+// all the stripes and there are only 3 threads, one of the threads will
+// get the tasks with the 4th stripe. However, there is a dependence in
+// CardTableExtension::scavenge_contents_parallel() on the number
+// of tasks created. In scavenge_contents_parallel the distance
+// to the next stripe is calculated based on the number of tasks.
+// If the stripe width is ssize, a task's next stripe is at
+// ssize * number_of_tasks (= slice_stride). In this case after
+// finishing stripe 0 in slice 0, the thread finds the stripe 0 in slice1
+// by adding slice_stride to the start of stripe 0 in slice 0 to get
+// to the start of stride 0 in slice 1.
class OldToYoungRootsTask : public GCTask {
private:
PSOldGen* _gen;
HeapWord* _gen_top;
uint _stripe_number;
+ uint _stripe_total;
public:
- OldToYoungRootsTask(PSOldGen *gen, HeapWord* gen_top, uint stripe_number) :
- _gen(gen), _gen_top(gen_top), _stripe_number(stripe_number) { }
+ OldToYoungRootsTask(PSOldGen *gen,
+ HeapWord* gen_top,
+ uint stripe_number,
+ uint stripe_total) :
+ _gen(gen),
+ _gen_top(gen_top),
+ _stripe_number(stripe_number),
+ _stripe_total(stripe_total) { }
char* name() { return (char *)"old-to-young-roots-task"; }
--- a/hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -28,8 +28,10 @@
#include "memory/collectorPolicy.hpp"
#include "runtime/timer.hpp"
#include "utilities/ostream.hpp"
+#include "utilities/workgroup.hpp"
elapsedTimer AdaptiveSizePolicy::_minor_timer;
elapsedTimer AdaptiveSizePolicy::_major_timer;
+bool AdaptiveSizePolicy::_debug_perturbation = false;
// The throughput goal is implemented as
// _throughput_goal = 1 - ( 1 / (1 + gc_cost_ratio))
@@ -88,6 +90,134 @@
_young_gen_policy_is_ready = false;
}
+// If the number of GC threads was set on the command line,
+// use it.
+// Else
+// Calculate the number of GC threads based on the number of Java threads.
+// Calculate the number of GC threads based on the size of the heap.
+// Use the larger.
+
+int AdaptiveSizePolicy::calc_default_active_workers(uintx total_workers,
+ const uintx min_workers,
+ uintx active_workers,
+ uintx application_workers) {
+ // If the user has specifically set the number of
+ // GC threads, use them.
+
+ // If the user has turned off using a dynamic number of GC threads
+ // or the users has requested a specific number, set the active
+ // number of workers to all the workers.
+
+ uintx new_active_workers = total_workers;
+ uintx prev_active_workers = active_workers;
+ uintx active_workers_by_JT = 0;
+ uintx active_workers_by_heap_size = 0;
+
+ // Always use at least min_workers but use up to
+ // GCThreadsPerJavaThreads * application threads.
+ active_workers_by_JT =
+ MAX2((uintx) GCWorkersPerJavaThread * application_workers,
+ min_workers);
+
+ // Choose a number of GC threads based on the current size
+ // of the heap. This may be complicated because the size of
+ // the heap depends on factors such as the thoughput goal.
+ // Still a large heap should be collected by more GC threads.
+ active_workers_by_heap_size =
+ MAX2((size_t) 2U, Universe::heap()->capacity() / HeapSizePerGCThread);
+
+ uintx max_active_workers =
+ MAX2(active_workers_by_JT, active_workers_by_heap_size);
+
+ // Limit the number of workers to the the number created,
+ // (workers()).
+ new_active_workers = MIN2(max_active_workers,
+ (uintx) total_workers);
+
+ // Increase GC workers instantly but decrease them more
+ // slowly.
+ if (new_active_workers < prev_active_workers) {
+ new_active_workers =
+ MAX2(min_workers, (prev_active_workers + new_active_workers) / 2);
+ }
+
+ // Check once more that the number of workers is within the limits.
+ assert(min_workers <= total_workers, "Minimum workers not consistent with total workers");
+ assert(new_active_workers >= min_workers, "Minimum workers not observed");
+ assert(new_active_workers <= total_workers, "Total workers not observed");
+
+ if (ForceDynamicNumberOfGCThreads) {
+ // Assume this is debugging and jiggle the number of GC threads.
+ if (new_active_workers == prev_active_workers) {
+ if (new_active_workers < total_workers) {
+ new_active_workers++;
+ } else if (new_active_workers > min_workers) {
+ new_active_workers--;
+ }
+ }
+ if (new_active_workers == total_workers) {
+ if (_debug_perturbation) {
+ new_active_workers = min_workers;
+ }
+ _debug_perturbation = !_debug_perturbation;
+ }
+ assert((new_active_workers <= (uintx) ParallelGCThreads) &&
+ (new_active_workers >= min_workers),
+ "Jiggled active workers too much");
+ }
+
+ if (TraceDynamicGCThreads) {
+ gclog_or_tty->print_cr("GCTaskManager::calc_default_active_workers() : "
+ "active_workers(): %d new_acitve_workers: %d "
+ "prev_active_workers: %d\n"
+ " active_workers_by_JT: %d active_workers_by_heap_size: %d",
+ active_workers, new_active_workers, prev_active_workers,
+ active_workers_by_JT, active_workers_by_heap_size);
+ }
+ assert(new_active_workers > 0, "Always need at least 1");
+ return new_active_workers;
+}
+
+int AdaptiveSizePolicy::calc_active_workers(uintx total_workers,
+ uintx active_workers,
+ uintx application_workers) {
+ // If the user has specifically set the number of
+ // GC threads, use them.
+
+ // If the user has turned off using a dynamic number of GC threads
+ // or the users has requested a specific number, set the active
+ // number of workers to all the workers.
+
+ int new_active_workers;
+ if (!UseDynamicNumberOfGCThreads ||
+ (!FLAG_IS_DEFAULT(ParallelGCThreads) && !ForceDynamicNumberOfGCThreads)) {
+ new_active_workers = total_workers;
+ } else {
+ new_active_workers = calc_default_active_workers(total_workers,
+ 2, /* Minimum number of workers */
+ active_workers,
+ application_workers);
+ }
+ assert(new_active_workers > 0, "Always need at least 1");
+ return new_active_workers;
+}
+
+int AdaptiveSizePolicy::calc_active_conc_workers(uintx total_workers,
+ uintx active_workers,
+ uintx application_workers) {
+ if (!UseDynamicNumberOfGCThreads ||
+ (!FLAG_IS_DEFAULT(ConcGCThreads) && !ForceDynamicNumberOfGCThreads)) {
+ return ConcGCThreads;
+ } else {
+ int no_of_gc_threads = calc_default_active_workers(
+ total_workers,
+ 1, /* Minimum number of workers */
+ active_workers,
+ application_workers);
+ return no_of_gc_threads;
+ }
+}
+
bool AdaptiveSizePolicy::tenuring_threshold_change() const {
return decrement_tenuring_threshold_for_gc_cost() ||
increment_tenuring_threshold_for_gc_cost() ||
--- a/hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -187,6 +187,8 @@
julong _young_gen_change_for_minor_throughput;
julong _old_gen_change_for_major_throughput;
+ static const uint GCWorkersPerJavaThread = 2;
+
// Accessors
double gc_pause_goal_sec() const { return _gc_pause_goal_sec; }
@@ -331,6 +333,8 @@
// Return true if the policy suggested a change.
bool tenuring_threshold_change() const;
+ static bool _debug_perturbation;
+
public:
AdaptiveSizePolicy(size_t init_eden_size,
size_t init_promo_size,
@@ -338,6 +342,31 @@
double gc_pause_goal_sec,
uint gc_cost_ratio);
+ // Return number default GC threads to use in the next GC.
+ static int calc_default_active_workers(uintx total_workers,
+ const uintx min_workers,
+ uintx active_workers,
+ uintx application_workers);
+
+ // Return number of GC threads to use in the next GC.
+ // This is called sparingly so as not to change the
+ // number of GC workers gratuitously.
+ // For ParNew collections
+ // For PS scavenge and ParOld collections
+ // For G1 evacuation pauses (subject to update)
+ // Other collection phases inherit the number of
+ // GC workers from the calls above. For example,
+ // a CMS parallel remark uses the same number of GC
+ // workers as the most recent ParNew collection.
+ static int calc_active_workers(uintx total_workers,
+ uintx active_workers,
+ uintx application_workers);
+
+ // Return number of GC threads to use in the next concurrent GC phase.
+ static int calc_active_conc_workers(uintx total_workers,
+ uintx active_workers,
+ uintx application_workers);
+
bool is_gc_cms_adaptive_size_policy() {
return kind() == _gc_cms_adaptive_size_policy;
}
--- a/hotspot/src/share/vm/gc_implementation/shared/markSweep.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/shared/markSweep.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -196,8 +196,6 @@
static void mark_object(oop obj);
// Mark pointer and follow contents. Empty marking stack afterwards.
template <class T> static inline void follow_root(T* p);
- // Mark pointer and follow contents.
- template <class T> static inline void mark_and_follow(T* p);
// Check mark and maybe push on marking stack
template <class T> static inline void mark_and_push(T* p);
static inline void push_objarray(oop obj, size_t index);
--- a/hotspot/src/share/vm/gc_implementation/shared/markSweep.inline.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/gc_implementation/shared/markSweep.inline.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -63,18 +63,6 @@
follow_stack();
}
-template <class T> inline void MarkSweep::mark_and_follow(T* p) {
-// assert(Universe::heap()->is_in_reserved(p), "should be in object space");
- T heap_oop = oopDesc::load_heap_oop(p);
- if (!oopDesc::is_null(heap_oop)) {
- oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
- if (!obj->mark()->is_marked()) {
- mark_object(obj);
- obj->follow_contents();
- }
- }
-}
-
template <class T> inline void MarkSweep::mark_and_push(T* p) {
// assert(Universe::heap()->is_in_reserved(p), "should be in object space");
T heap_oop = oopDesc::load_heap_oop(p);
--- a/hotspot/src/share/vm/memory/cardTableModRefBS.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/memory/cardTableModRefBS.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -460,9 +460,43 @@
OopsInGenClosure* cl,
CardTableRS* ct) {
if (!mr.is_empty()) {
- int n_threads = SharedHeap::heap()->n_par_threads();
- if (n_threads > 0) {
+ // Caller (process_strong_roots()) claims that all GC threads
+ // execute this call. With UseDynamicNumberOfGCThreads now all
+ // active GC threads execute this call. The number of active GC
+ // threads needs to be passed to par_non_clean_card_iterate_work()
+ // to get proper partitioning and termination.
+ //
+ // This is an example of where n_par_threads() is used instead
+ // of workers()->active_workers(). n_par_threads can be set to 0 to
+ // turn off parallelism. For example when this code is called as
+ // part of verification and SharedHeap::process_strong_roots() is being
+ // used, then n_par_threads() may have been set to 0. active_workers
+ // is not overloaded with the meaning that it is a switch to disable
+ // parallelism and so keeps the meaning of the number of
+ // active gc workers. If parallelism has not been shut off by
+ // setting n_par_threads to 0, then n_par_threads should be
+ // equal to active_workers. When a different mechanism for shutting
+ // off parallelism is used, then active_workers can be used in
+ // place of n_par_threads.
+ // This is an example of a path where n_par_threads is
+ // set to 0 to turn off parallism.
+ // [7] CardTableModRefBS::non_clean_card_iterate()
+ // [8] CardTableRS::younger_refs_in_space_iterate()
+ // [9] Generation::younger_refs_in_space_iterate()
+ // [10] OneContigSpaceCardGeneration::younger_refs_iterate()
+ // [11] CompactingPermGenGen::younger_refs_iterate()
+ // [12] CardTableRS::younger_refs_iterate()
+ // [13] SharedHeap::process_strong_roots()
+ // [14] G1CollectedHeap::verify()
+ // [15] Universe::verify()
+ // [16] G1CollectedHeap::do_collection_pause_at_safepoint()
+ //
+ int n_threads = SharedHeap::heap()->n_par_threads();
+ bool is_par = n_threads > 0;
+ if (is_par) {
#ifndef SERIALGC
+ assert(SharedHeap::heap()->n_par_threads() ==
+ SharedHeap::heap()->workers()->active_workers(), "Mismatch");
non_clean_card_iterate_parallel_work(sp, mr, cl, ct, n_threads);
#else // SERIALGC
fatal("Parallel gc not supported here.");
@@ -489,6 +523,10 @@
// change their values in any manner.
void CardTableModRefBS::non_clean_card_iterate_serial(MemRegion mr,
MemRegionClosure* cl) {
+ bool is_par = (SharedHeap::heap()->n_par_threads() > 0);
+ assert(!is_par ||
+ (SharedHeap::heap()->n_par_threads() ==
+ SharedHeap::heap()->workers()->active_workers()), "Mismatch");
for (int i = 0; i < _cur_covered_regions; i++) {
MemRegion mri = mr.intersection(_covered[i]);
if (mri.word_size() > 0) {
@@ -624,23 +662,6 @@
return MemRegion(mr.end(), mr.end());
}
-// Set all the dirty cards in the given region to "precleaned" state.
-void CardTableModRefBS::preclean_dirty_cards(MemRegion mr) {
- for (int i = 0; i < _cur_covered_regions; i++) {
- MemRegion mri = mr.intersection(_covered[i]);
- if (!mri.is_empty()) {
- jbyte *cur_entry, *limit;
- for (cur_entry = byte_for(mri.start()), limit = byte_for(mri.last());
- cur_entry <= limit;
- cur_entry++) {
- if (*cur_entry == dirty_card) {
- *cur_entry = precleaned_card;
- }
- }
- }
- }
-}
-
uintx CardTableModRefBS::ct_max_alignment_constraint() {
return card_size * os::vm_page_size();
}
--- a/hotspot/src/share/vm/memory/cardTableModRefBS.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/memory/cardTableModRefBS.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -435,9 +435,6 @@
MemRegion dirty_card_range_after_reset(MemRegion mr, bool reset,
int reset_val);
- // Set all the dirty cards in the given region to precleaned state.
- void preclean_dirty_cards(MemRegion mr);
-
// Provide read-only access to the card table array.
const jbyte* byte_for_const(const void* p) const {
return byte_for(p);
--- a/hotspot/src/share/vm/memory/cardTableRS.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/memory/cardTableRS.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -164,7 +164,13 @@
ClearNoncleanCardWrapper::ClearNoncleanCardWrapper(
DirtyCardToOopClosure* dirty_card_closure, CardTableRS* ct) :
_dirty_card_closure(dirty_card_closure), _ct(ct) {
+ // Cannot yet substitute active_workers for n_par_threads
+ // in the case where parallelism is being turned off by
+ // setting n_par_threads to 0.
_is_par = (SharedHeap::heap()->n_par_threads() > 0);
+ assert(!_is_par ||
+ (SharedHeap::heap()->n_par_threads() ==
+ SharedHeap::heap()->workers()->active_workers()), "Mismatch");
}
void ClearNoncleanCardWrapper::do_MemRegion(MemRegion mr) {
--- a/hotspot/src/share/vm/memory/sharedHeap.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/memory/sharedHeap.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -58,7 +58,6 @@
_perm_gen(NULL), _rem_set(NULL),
_strong_roots_parity(0),
_process_strong_tasks(new SubTasksDone(SH_PS_NumElements)),
- _n_par_threads(0),
_workers(NULL)
{
if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) {
@@ -80,6 +79,14 @@
}
}
+int SharedHeap::n_termination() {
+ return _process_strong_tasks->n_threads();
+}
+
+void SharedHeap::set_n_termination(int t) {
+ _process_strong_tasks->set_n_threads(t);
+}
+
bool SharedHeap::heap_lock_held_for_gc() {
Thread* t = Thread::current();
return Heap_lock->owned_by_self()
@@ -144,6 +151,10 @@
StrongRootsScope srs(this, activate_scope);
// General strong roots.
assert(_strong_roots_parity != 0, "must have called prologue code");
+ // _n_termination for _process_strong_tasks should be set up stream
+ // in a method not running in a GC worker. Otherwise the GC worker
+ // could be trying to change the termination condition while the task
+ // is executing in another GC worker.
if (!_process_strong_tasks->is_task_claimed(SH_PS_Universe_oops_do)) {
Universe::oops_do(roots);
// Consider perm-gen discovered lists to be strong.
--- a/hotspot/src/share/vm/memory/sharedHeap.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/memory/sharedHeap.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -49,6 +49,62 @@
class CollectorPolicy;
class KlassHandle;
+// Note on use of FlexibleWorkGang's for GC.
+// There are three places where task completion is determined.
+// In
+// 1) ParallelTaskTerminator::offer_termination() where _n_threads
+// must be set to the correct value so that count of workers that
+// have offered termination will exactly match the number
+// working on the task. Tasks such as those derived from GCTask
+// use ParallelTaskTerminator's. Tasks that want load balancing
+// by work stealing use this method to gauge completion.
+// 2) SubTasksDone has a variable _n_threads that is used in
+// all_tasks_completed() to determine completion. all_tasks_complete()
+// counts the number of tasks that have been done and then reset
+// the SubTasksDone so that it can be used again. When the number of
+// tasks is set to the number of GC workers, then _n_threads must
+// be set to the number of active GC workers. G1CollectedHeap,
+// HRInto_G1RemSet, GenCollectedHeap and SharedHeap have SubTasksDone.
+// This seems too many.
+// 3) SequentialSubTasksDone has an _n_threads that is used in
+// a way similar to SubTasksDone and has the same dependency on the
+// number of active GC workers. CompactibleFreeListSpace and Space
+// have SequentialSubTasksDone's.
+// Example of using SubTasksDone and SequentialSubTasksDone
+// G1CollectedHeap::g1_process_strong_roots() calls
+// process_strong_roots(false, // no scoping; this is parallel code
+// collecting_perm_gen, so,
+// &buf_scan_non_heap_roots,
+// &eager_scan_code_roots,
+// &buf_scan_perm);
+// which delegates to SharedHeap::process_strong_roots() and uses
+// SubTasksDone* _process_strong_tasks to claim tasks.
+// process_strong_roots() calls
+// rem_set()->younger_refs_iterate(perm_gen(), perm_blk);
+// to scan the card table and which eventually calls down into
+// CardTableModRefBS::par_non_clean_card_iterate_work(). This method
+// uses SequentialSubTasksDone* _pst to claim tasks.
+// Both SubTasksDone and SequentialSubTasksDone call their method
+// all_tasks_completed() to count the number of GC workers that have
+// finished their work. That logic is "when all the workers are
+// finished the tasks are finished".
+//
+// The pattern that appears in the code is to set _n_threads
+// to a value > 1 before a task that you would like executed in parallel
+// and then to set it to 0 after that task has completed. A value of
+// 0 is a "special" value in set_n_threads() which translates to
+// setting _n_threads to 1.
+//
+// Some code uses _n_terminiation to decide if work should be done in
+// parallel. The notorious possibly_parallel_oops_do() in threads.cpp
+// is an example of such code. Look for variable "is_par" for other
+// examples.
+//
+// The active_workers is not reset to 0 after a parallel phase. It's
+// value may be used in later phases and in one instance at least
+// (the parallel remark) it has to be used (the parallel remark depends
+// on the partitioning done in the previous parallel scavenge).
+
class SharedHeap : public CollectedHeap {
friend class VMStructs;
@@ -84,11 +140,6 @@
// If we're doing parallel GC, use this gang of threads.
FlexibleWorkGang* _workers;
- // Number of parallel threads currently working on GC tasks.
- // O indicates use sequential code; 1 means use parallel code even with
- // only one thread, for performance testing purposes.
- int _n_par_threads;
-
// Full initialization is done in a concrete subtype's "initialize"
// function.
SharedHeap(CollectorPolicy* policy_);
@@ -107,6 +158,7 @@
CollectorPolicy *collector_policy() const { return _collector_policy; }
void set_barrier_set(BarrierSet* bs);
+ SubTasksDone* process_strong_tasks() { return _process_strong_tasks; }
// Does operations required after initialization has been done.
virtual void post_initialize();
@@ -198,13 +250,6 @@
FlexibleWorkGang* workers() const { return _workers; }
- // Sets the number of parallel threads that will be doing tasks
- // (such as process strong roots) subsequently.
- virtual void set_par_threads(int t);
-
- // Number of threads currently working on GC tasks.
- int n_par_threads() { return _n_par_threads; }
-
// Invoke the "do_oop" method the closure "roots" on all root locations.
// If "collecting_perm_gen" is false, then roots that may only contain
// references to permGen objects are not scanned; instead, in that case,
@@ -240,6 +285,13 @@
virtual void gc_prologue(bool full) = 0;
virtual void gc_epilogue(bool full) = 0;
+ // Sets the number of parallel threads that will be doing tasks
+ // (such as process strong roots) subsequently.
+ virtual void set_par_threads(int t);
+
+ int n_termination();
+ void set_n_termination(int t);
+
//
// New methods from CollectedHeap
//
--- a/hotspot/src/share/vm/memory/space.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/memory/space.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -533,7 +533,8 @@
* by the MarkSweepAlwaysCompactCount parameter. \
*/ \
int invocations = SharedHeap::heap()->perm_gen()->stat_record()->invocations;\
- bool skip_dead = ((invocations % MarkSweepAlwaysCompactCount) != 0); \
+ bool skip_dead = (MarkSweepAlwaysCompactCount < 1) \
+ ||((invocations % MarkSweepAlwaysCompactCount) != 0); \
\
size_t allowed_deadspace = 0; \
if (skip_dead) { \
--- a/hotspot/src/share/vm/oops/objArrayOop.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/oops/objArrayOop.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -34,7 +34,7 @@
friend class objArrayKlass;
friend class Runtime1;
friend class psPromotionManager;
- friend class CSMarkOopClosure;
+ friend class CSetMarkOopClosure;
friend class G1ParScanPartialArrayClosure;
template <class T> T* obj_at_addr(int index) const {
--- a/hotspot/src/share/vm/runtime/arguments.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/runtime/arguments.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -1394,8 +1394,8 @@
// If no heap maximum was requested explicitly, use some reasonable fraction
// of the physical memory, up to a maximum of 1GB.
if (UseParallelGC) {
- FLAG_SET_ERGO(uintx, ParallelGCThreads,
- Abstract_VM_Version::parallel_worker_threads());
+ FLAG_SET_DEFAULT(ParallelGCThreads,
+ Abstract_VM_Version::parallel_worker_threads());
// If InitialSurvivorRatio or MinSurvivorRatio were not specified, but the
// SurvivorRatio has been set, reset their default values to SurvivorRatio +
--- a/hotspot/src/share/vm/runtime/globals.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/runtime/globals.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -1416,6 +1416,21 @@
product(uintx, ParallelGCThreads, 0, \
"Number of parallel threads parallel gc will use") \
\
+ product(bool, UseDynamicNumberOfGCThreads, false, \
+ "Dynamically choose the number of parallel threads " \
+ "parallel gc will use") \
+ \
+ diagnostic(bool, ForceDynamicNumberOfGCThreads, false, \
+ "Force dynamic selection of the number of" \
+ "parallel threads parallel gc will use to aid debugging") \
+ \
+ product(uintx, HeapSizePerGCThread, ScaleForWordSize(64*M), \
+ "Size of heap (bytes) per GC thread used in calculating the " \
+ "number of GC threads") \
+ \
+ product(bool, TraceDynamicGCThreads, false, \
+ "Trace the dynamic GC thread usage") \
+ \
develop(bool, ParallelOldGCSplitALot, false, \
"Provoke splitting (copying data from a young gen space to" \
"multiple destination spaces)") \
@@ -2357,7 +2372,7 @@
develop(bool, TraceGCTaskQueue, false, \
"Trace actions of the GC task queues") \
\
- develop(bool, TraceGCTaskThread, false, \
+ diagnostic(bool, TraceGCTaskThread, false, \
"Trace actions of the GC task threads") \
\
product(bool, PrintParallelOldGCPhaseTimes, false, \
--- a/hotspot/src/share/vm/runtime/thread.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/runtime/thread.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -778,12 +778,12 @@
return true;
} else {
guarantee(res == strong_roots_parity, "Or else what?");
- assert(SharedHeap::heap()->n_par_threads() > 0,
- "Should only fail when parallel.");
+ assert(SharedHeap::heap()->workers()->active_workers() > 0,
+ "Should only fail when parallel.");
return false;
}
}
- assert(SharedHeap::heap()->n_par_threads() > 0,
+ assert(SharedHeap::heap()->workers()->active_workers() > 0,
"Should only fail when parallel.");
return false;
}
@@ -3939,7 +3939,15 @@
// root groups. Overhead should be small enough to use all the time,
// even in sequential code.
SharedHeap* sh = SharedHeap::heap();
- bool is_par = (sh->n_par_threads() > 0);
+ // Cannot yet substitute active_workers for n_par_threads
+ // because of G1CollectedHeap::verify() use of
+ // SharedHeap::process_strong_roots(). n_par_threads == 0 will
+ // turn off parallelism in process_strong_roots while active_workers
+ // is being used for parallelism elsewhere.
+ bool is_par = sh->n_par_threads() > 0;
+ assert(!is_par ||
+ (SharedHeap::heap()->n_par_threads() ==
+ SharedHeap::heap()->workers()->active_workers()), "Mismatch");
int cp = SharedHeap::heap()->strong_roots_parity();
ALL_JAVA_THREADS(p) {
if (p->claim_oops_do(is_par, cp)) {
--- a/hotspot/src/share/vm/services/memoryManager.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/services/memoryManager.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -168,10 +168,8 @@
// initialize the arrays for memory usage
_before_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
_after_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
- size_t len = num_pools * sizeof(MemoryUsage);
- memset(_before_gc_usage_array, 0, len);
- memset(_after_gc_usage_array, 0, len);
_usage_array_size = num_pools;
+ clear();
}
GCStatInfo::~GCStatInfo() {
@@ -304,12 +302,8 @@
pool->set_last_collection_usage(usage);
LowMemoryDetector::detect_after_gc_memory(pool);
}
- if(is_notification_enabled()) {
- bool isMajorGC = this == MemoryService::get_major_gc_manager();
- GCNotifier::pushNotification(this, isMajorGC ? "end of major GC" : "end of minor GC",
- GCCause::to_string(cause));
- }
}
+
if (countCollection) {
_num_collections++;
// alternately update two objects making one public when complete
@@ -321,6 +315,12 @@
// reset the current stat for diagnosability purposes
_current_gc_stat->clear();
}
+
+ if (is_notification_enabled()) {
+ bool isMajorGC = this == MemoryService::get_major_gc_manager();
+ GCNotifier::pushNotification(this, isMajorGC ? "end of major GC" : "end of minor GC",
+ GCCause::to_string(cause));
+ }
}
}
--- a/hotspot/src/share/vm/utilities/workgroup.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/utilities/workgroup.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -57,7 +57,6 @@
bool are_GC_task_threads,
bool are_ConcurrentGC_threads) :
AbstractWorkGang(name, are_GC_task_threads, are_ConcurrentGC_threads) {
- // Save arguments.
_total_workers = workers;
}
@@ -127,6 +126,12 @@
}
void WorkGang::run_task(AbstractGangTask* task) {
+ run_task(task, total_workers());
+}
+
+void WorkGang::run_task(AbstractGangTask* task, uint no_of_parallel_workers) {
+ task->set_for_termination(no_of_parallel_workers);
+
// This thread is executed by the VM thread which does not block
// on ordinary MutexLocker's.
MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
@@ -143,22 +148,32 @@
// Tell the workers to get to work.
monitor()->notify_all();
// Wait for them to be finished
- while (finished_workers() < total_workers()) {
+ while (finished_workers() < (int) no_of_parallel_workers) {
if (TraceWorkGang) {
tty->print_cr("Waiting in work gang %s: %d/%d finished sequence %d",
- name(), finished_workers(), total_workers(),
+ name(), finished_workers(), no_of_parallel_workers,
_sequence_number);
}
monitor()->wait(/* no_safepoint_check */ true);
}
_task = NULL;
if (TraceWorkGang) {
- tty->print_cr("/nFinished work gang %s: %d/%d sequence %d",
- name(), finished_workers(), total_workers(),
+ tty->print_cr("\nFinished work gang %s: %d/%d sequence %d",
+ name(), finished_workers(), no_of_parallel_workers,
_sequence_number);
+ Thread* me = Thread::current();
+ tty->print_cr(" T: 0x%x VM_thread: %d", me, me->is_VM_thread());
}
}
+void FlexibleWorkGang::run_task(AbstractGangTask* task) {
+ // If active_workers() is passed, _finished_workers
+ // must only be incremented for workers that find non_null
+ // work (as opposed to all those that just check that the
+ // task is not null).
+ WorkGang::run_task(task, (uint) active_workers());
+}
+
void AbstractWorkGang::stop() {
// Tell all workers to terminate, then wait for them to become inactive.
MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
@@ -168,10 +183,10 @@
_task = NULL;
_terminate = true;
monitor()->notify_all();
- while (finished_workers() < total_workers()) {
+ while (finished_workers() < active_workers()) {
if (TraceWorkGang) {
tty->print_cr("Waiting in work gang %s: %d/%d finished",
- name(), finished_workers(), total_workers());
+ name(), finished_workers(), active_workers());
}
monitor()->wait(/* no_safepoint_check */ true);
}
@@ -275,10 +290,12 @@
// Check for new work.
if ((data.task() != NULL) &&
(data.sequence_number() != previous_sequence_number)) {
- gang()->internal_note_start();
- gang_monitor->notify_all();
- part = gang()->started_workers() - 1;
- break;
+ if (gang()->needs_more_workers()) {
+ gang()->internal_note_start();
+ gang_monitor->notify_all();
+ part = gang()->started_workers() - 1;
+ break;
+ }
}
// Nothing to do.
gang_monitor->wait(/* no_safepoint_check */ true);
@@ -350,6 +367,9 @@
#endif /* PRODUCT */
+// FlexibleWorkGang
+
+
// *** WorkGangBarrierSync
WorkGangBarrierSync::WorkGangBarrierSync()
@@ -411,10 +431,8 @@
}
void SubTasksDone::set_n_threads(int t) {
-#ifdef ASSERT
assert(_claimed == 0 || _threads_completed == _n_threads,
"should not be called while tasks are being processed!");
-#endif
_n_threads = (t == 0 ? 1 : t);
}
--- a/hotspot/src/share/vm/utilities/workgroup.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/utilities/workgroup.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -96,11 +96,14 @@
protected:
// Constructor and desctructor: only construct subclasses.
- AbstractGangTask(const char* name) {
+ AbstractGangTask(const char* name)
+ {
NOT_PRODUCT(_name = name);
_counter = 0;
}
virtual ~AbstractGangTask() { }
+
+public:
};
class AbstractGangTaskWOopQueues : public AbstractGangTask {
@@ -116,6 +119,7 @@
OopTaskQueueSet* queues() { return _queues; }
};
+
// Class AbstractWorkGang:
// An abstract class representing a gang of workers.
// You subclass this to supply an implementation of run_task().
@@ -130,6 +134,8 @@
virtual void run_task(AbstractGangTask* task) = 0;
// Stop and terminate all workers.
virtual void stop();
+ // Return true if more workers should be applied to the task.
+ virtual bool needs_more_workers() const { return true; }
public:
// Debugging.
const char* name() const;
@@ -287,20 +293,62 @@
AbstractWorkGang* gang() const { return _gang; }
};
+// Dynamic number of worker threads
+//
+// This type of work gang is used to run different numbers of
+// worker threads at different times. The
+// number of workers run for a task is "_active_workers"
+// instead of "_total_workers" in a WorkGang. The method
+// "needs_more_workers()" returns true until "_active_workers"
+// have been started and returns false afterwards. The
+// implementation of "needs_more_workers()" in WorkGang always
+// returns true so that all workers are started. The method
+// "loop()" in GangWorker was modified to ask "needs_more_workers()"
+// in its loop to decide if it should start working on a task.
+// A worker in "loop()" waits for notification on the WorkGang
+// monitor and execution of each worker as it checks for work
+// is serialized via the same monitor. The "needs_more_workers()"
+// call is serialized and additionally the calculation for the
+// "part" (effectively the worker id for executing the task) is
+// serialized to give each worker a unique "part". Workers that
+// are not needed for this tasks (i.e., "_active_workers" have
+// been started before it, continue to wait for work.
+
class FlexibleWorkGang: public WorkGang {
+ // The currently active workers in this gang.
+ // This is a number that is dynamically adjusted
+ // and checked in the run_task() method at each invocation.
+ // As described above _active_workers determines the number
+ // of threads started on a task. It must also be used to
+ // determine completion.
+
protected:
int _active_workers;
public:
// Constructor and destructor.
+ // Initialize active_workers to a minimum value. Setting it to
+ // the parameter "workers" will initialize it to a maximum
+ // value which is not desirable.
FlexibleWorkGang(const char* name, int workers,
bool are_GC_task_threads,
bool are_ConcurrentGC_threads) :
- WorkGang(name, workers, are_GC_task_threads, are_ConcurrentGC_threads) {
- _active_workers = ParallelGCThreads;
- };
+ WorkGang(name, workers, are_GC_task_threads, are_ConcurrentGC_threads),
+ _active_workers(UseDynamicNumberOfGCThreads ? 1 : ParallelGCThreads) {};
// Accessors for fields
virtual int active_workers() const { return _active_workers; }
- void set_active_workers(int v) { _active_workers = v; }
+ void set_active_workers(int v) {
+ assert(v <= _total_workers,
+ "Trying to set more workers active than there are");
+ _active_workers = MIN2(v, _total_workers);
+ assert(v != 0, "Trying to set active workers to 0");
+ _active_workers = MAX2(1, _active_workers);
+ assert(UseDynamicNumberOfGCThreads || _active_workers == _total_workers,
+ "Unless dynamic should use total workers");
+ }
+ virtual void run_task(AbstractGangTask* task);
+ virtual bool needs_more_workers() const {
+ return _started_workers < _active_workers;
+ }
};
// Work gangs in garbage collectors: 2009-06-10
@@ -357,6 +405,11 @@
class SubTasksDone: public CHeapObj {
jint* _tasks;
int _n_tasks;
+ // _n_threads is used to determine when a sub task is done.
+ // It does not control how many threads will execute the subtask
+ // but must be initialized to the number that do execute the task
+ // in order to correctly decide when the subtask is done (all the
+ // threads working on the task have finished).
int _n_threads;
jint _threads_completed;
#ifdef ASSERT
--- a/hotspot/src/share/vm/utilities/yieldingWorkgroup.cpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/utilities/yieldingWorkgroup.cpp Fri Dec 02 15:11:18 2011 -0800
@@ -125,7 +125,7 @@
if (requested_size != 0) {
_active_workers = MIN2(requested_size, total_workers());
} else {
- _active_workers = total_workers();
+ _active_workers = active_workers();
}
new_task->set_actual_size(_active_workers);
new_task->set_for_termination(_active_workers);
@@ -148,22 +148,22 @@
for (Status status = yielding_task()->status();
status != COMPLETED && status != YIELDED && status != ABORTED;
status = yielding_task()->status()) {
- assert(started_workers() <= total_workers(), "invariant");
- assert(finished_workers() <= total_workers(), "invariant");
- assert(yielded_workers() <= total_workers(), "invariant");
+ assert(started_workers() <= active_workers(), "invariant");
+ assert(finished_workers() <= active_workers(), "invariant");
+ assert(yielded_workers() <= active_workers(), "invariant");
monitor()->wait(Mutex::_no_safepoint_check_flag);
}
switch (yielding_task()->status()) {
case COMPLETED:
case ABORTED: {
- assert(finished_workers() == total_workers(), "Inconsistent status");
+ assert(finished_workers() == active_workers(), "Inconsistent status");
assert(yielded_workers() == 0, "Invariant");
reset(); // for next task; gang<->task binding released
break;
}
case YIELDED: {
assert(yielded_workers() > 0, "Invariant");
- assert(yielded_workers() + finished_workers() == total_workers(),
+ assert(yielded_workers() + finished_workers() == active_workers(),
"Inconsistent counts");
break;
}
@@ -182,7 +182,6 @@
MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
assert(task() != NULL && task() == gang_task, "Incorrect usage");
- // assert(_active_workers == total_workers(), "For now");
assert(_started_workers == _active_workers, "Precondition");
assert(_yielded_workers > 0 && yielding_task()->status() == YIELDED,
"Else why are we calling continue_task()");
@@ -202,7 +201,7 @@
void YieldingFlexibleWorkGang::yield() {
assert(task() != NULL, "Inconsistency; should have task binding");
MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
- assert(yielded_workers() < total_workers(), "Consistency check");
+ assert(yielded_workers() < active_workers(), "Consistency check");
if (yielding_task()->status() == ABORTING) {
// Do not yield; we need to abort as soon as possible
// XXX NOTE: This can cause a performance pathology in the
@@ -213,7 +212,7 @@
// us to return at each potential yield point.
return;
}
- if (++_yielded_workers + finished_workers() == total_workers()) {
+ if (++_yielded_workers + finished_workers() == active_workers()) {
yielding_task()->set_status(YIELDED);
monitor()->notify_all();
} else {
--- a/hotspot/src/share/vm/utilities/yieldingWorkgroup.hpp Wed Jul 05 17:57:09 2017 +0200
+++ b/hotspot/src/share/vm/utilities/yieldingWorkgroup.hpp Fri Dec 02 15:11:18 2011 -0800
@@ -199,17 +199,11 @@
void abort();
private:
- int _active_workers;
int _yielded_workers;
void wait_for_gang();
public:
// Accessors for fields
- int active_workers() const {
- return _active_workers;
- }
-
- // Accessors for fields
int yielded_workers() const {
return _yielded_workers;
}