--- a/hotspot/src/os/linux/vm/globals_linux.hpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/os/linux/vm/globals_linux.hpp Mon May 02 07:08:53 2011 -0700
@@ -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
@@ -47,7 +47,7 @@
// Defines Linux-specific default values. The flags are available on all
// platforms, but they may have different default values on other platforms.
//
-define_pd_global(bool, UseLargePages, false);
+define_pd_global(bool, UseLargePages, true);
define_pd_global(bool, UseLargePagesIndividualAllocation, false);
define_pd_global(bool, UseOSErrorReporting, false);
define_pd_global(bool, UseThreadPriorities, true) ;
--- a/hotspot/src/os/linux/vm/os_linux.cpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/os/linux/vm/os_linux.cpp Mon May 02 07:08:53 2011 -0700
@@ -2914,16 +2914,21 @@
static size_t _large_page_size = 0;
-bool os::large_page_init() {
+void os::large_page_init() {
if (!UseLargePages) {
UseHugeTLBFS = false;
UseSHM = false;
- return false;
+ return;
}
if (FLAG_IS_DEFAULT(UseHugeTLBFS) && FLAG_IS_DEFAULT(UseSHM)) {
- // Our user has not expressed a preference, so we'll try both.
- UseHugeTLBFS = UseSHM = true;
+ // If UseLargePages is specified on the command line try both methods,
+ // if it's default, then try only HugeTLBFS.
+ if (FLAG_IS_DEFAULT(UseLargePages)) {
+ UseHugeTLBFS = true;
+ } else {
+ UseHugeTLBFS = UseSHM = true;
+ }
}
if (LargePageSizeInBytes) {
@@ -2978,7 +2983,6 @@
_page_sizes[1] = default_page_size;
_page_sizes[2] = 0;
}
-
UseHugeTLBFS = UseHugeTLBFS &&
Linux::hugetlbfs_sanity_check(warn_on_failure, _large_page_size);
@@ -2988,12 +2992,6 @@
UseLargePages = UseHugeTLBFS || UseSHM;
set_coredump_filter();
-
- // Large page support is available on 2.6 or newer kernel, some vendors
- // (e.g. Redhat) have backported it to their 2.4 based distributions.
- // We optimistically assume the support is available. If later it turns out
- // not true, VM will automatically switch to use regular page size.
- return true;
}
#ifndef SHM_HUGETLB
@@ -4118,7 +4116,7 @@
#endif
}
- FLAG_SET_DEFAULT(UseLargePages, os::large_page_init());
+ os::large_page_init();
// initialize suspend/resume support - must do this before signal_sets_init()
if (SR_initialize() != 0) {
--- a/hotspot/src/os/solaris/vm/os_solaris.cpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/os/solaris/vm/os_solaris.cpp Mon May 02 07:08:53 2011 -0700
@@ -3336,11 +3336,11 @@
return true;
}
-bool os::large_page_init() {
+void os::large_page_init() {
if (!UseLargePages) {
UseISM = false;
UseMPSS = false;
- return false;
+ return;
}
// print a warning if any large page related flag is specified on command line
@@ -3361,7 +3361,6 @@
Solaris::mpss_sanity_check(warn_on_failure, &_large_page_size);
UseLargePages = UseISM || UseMPSS;
- return UseLargePages;
}
bool os::Solaris::set_mpss_range(caddr_t start, size_t bytes, size_t align) {
@@ -4992,7 +4991,7 @@
#endif
}
- FLAG_SET_DEFAULT(UseLargePages, os::large_page_init());
+ os::large_page_init();
// Check minimum allowable stack size for thread creation and to initialize
// the java system classes, including StackOverflowError - depends on page
--- a/hotspot/src/os/windows/vm/os_windows.cpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/os/windows/vm/os_windows.cpp Mon May 02 07:08:53 2011 -0700
@@ -2762,8 +2762,8 @@
_hToken = NULL;
}
-bool os::large_page_init() {
- if (!UseLargePages) return false;
+void os::large_page_init() {
+ if (!UseLargePages) return;
// print a warning if any large page related flag is specified on command line
bool warn_on_failure = !FLAG_IS_DEFAULT(UseLargePages) ||
@@ -2808,7 +2808,7 @@
}
cleanup_after_large_page_init();
- return success;
+ UseLargePages = success;
}
// On win32, one cannot release just a part of reserved memory, it's an
@@ -3561,7 +3561,7 @@
#endif
}
- FLAG_SET_DEFAULT(UseLargePages, os::large_page_init());
+ os::large_page_init();
// Setup Windows Exceptions
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Mon May 02 07:08:53 2011 -0700
@@ -826,6 +826,14 @@
void ConcurrentMark::checkpointRootsInitialPost() {
G1CollectedHeap* g1h = G1CollectedHeap::heap();
+ // If we force an overflow during remark, the remark operation will
+ // actually abort and we'll restart concurrent marking. If we always
+ // force an oveflow during remark we'll never actually complete the
+ // marking phase. So, we initilize this here, at the start of the
+ // cycle, so that at the remaining overflow number will decrease at
+ // every remark and we'll eventually not need to cause one.
+ force_overflow_stw()->init();
+
// For each region note start of marking.
NoteStartOfMarkHRClosure startcl;
g1h->heap_region_iterate(&startcl);
@@ -893,27 +901,37 @@
}
/*
- Notice that in the next two methods, we actually leave the STS
- during the barrier sync and join it immediately afterwards. If we
- do not do this, this then the following deadlock can occur: one
- thread could be in the barrier sync code, waiting for the other
- thread to also sync up, whereas another one could be trying to
- yield, while also waiting for the other threads to sync up too.
-
- Because the thread that does the sync barrier has left the STS, it
- is possible to be suspended for a Full GC or an evacuation pause
- could occur. This is actually safe, since the entering the sync
- barrier is one of the last things do_marking_step() does, and it
- doesn't manipulate any data structures afterwards.
-*/
+ * Notice that in the next two methods, we actually leave the STS
+ * during the barrier sync and join it immediately afterwards. If we
+ * do not do this, the following deadlock can occur: one thread could
+ * be in the barrier sync code, waiting for the other thread to also
+ * sync up, whereas another one could be trying to yield, while also
+ * waiting for the other threads to sync up too.
+ *
+ * Note, however, that this code is also used during remark and in
+ * this case we should not attempt to leave / enter the STS, otherwise
+ * we'll either hit an asseert (debug / fastdebug) or deadlock
+ * (product). So we should only leave / enter the STS if we are
+ * operating concurrently.
+ *
+ * Because the thread that does the sync barrier has left the STS, it
+ * is possible to be suspended for a Full GC or an evacuation pause
+ * could occur. This is actually safe, since the entering the sync
+ * barrier is one of the last things do_marking_step() does, and it
+ * doesn't manipulate any data structures afterwards.
+ */
void ConcurrentMark::enter_first_sync_barrier(int task_num) {
if (verbose_low())
gclog_or_tty->print_cr("[%d] entering first barrier", task_num);
- ConcurrentGCThread::stsLeave();
+ if (concurrent()) {
+ ConcurrentGCThread::stsLeave();
+ }
_first_overflow_barrier_sync.enter();
- ConcurrentGCThread::stsJoin();
+ if (concurrent()) {
+ ConcurrentGCThread::stsJoin();
+ }
// at this point everyone should have synced up and not be doing any
// more work
@@ -923,7 +941,12 @@
// let task 0 do this
if (task_num == 0) {
// task 0 is responsible for clearing the global data structures
- clear_marking_state();
+ // We should be here because of an overflow. During STW we should
+ // not clear the overflow flag since we rely on it being true when
+ // we exit this method to abort the pause and restart concurent
+ // marking.
+ clear_marking_state(concurrent() /* clear_overflow */);
+ force_overflow()->update();
if (PrintGC) {
gclog_or_tty->date_stamp(PrintGCDateStamps);
@@ -940,15 +963,45 @@
if (verbose_low())
gclog_or_tty->print_cr("[%d] entering second barrier", task_num);
- ConcurrentGCThread::stsLeave();
+ if (concurrent()) {
+ ConcurrentGCThread::stsLeave();
+ }
_second_overflow_barrier_sync.enter();
- ConcurrentGCThread::stsJoin();
+ if (concurrent()) {
+ ConcurrentGCThread::stsJoin();
+ }
// at this point everything should be re-initialised and ready to go
if (verbose_low())
gclog_or_tty->print_cr("[%d] leaving second barrier", task_num);
}
+#ifndef PRODUCT
+void ForceOverflowSettings::init() {
+ _num_remaining = G1ConcMarkForceOverflow;
+ _force = false;
+ update();
+}
+
+void ForceOverflowSettings::update() {
+ if (_num_remaining > 0) {
+ _num_remaining -= 1;
+ _force = true;
+ } else {
+ _force = false;
+ }
+}
+
+bool ForceOverflowSettings::should_force() {
+ if (_force) {
+ _force = false;
+ return true;
+ } else {
+ return false;
+ }
+}
+#endif // !PRODUCT
+
void ConcurrentMark::grayRoot(oop p) {
HeapWord* addr = (HeapWord*) p;
// We can't really check against _heap_start and _heap_end, since it
@@ -1117,6 +1170,7 @@
_restart_for_overflow = false;
size_t active_workers = MAX2((size_t) 1, parallel_marking_threads());
+ force_overflow_conc()->init();
set_phase(active_workers, true /* concurrent */);
CMConcurrentMarkingTask markingTask(this, cmThread());
@@ -1845,7 +1899,7 @@
while (!_cleanup_list.is_empty()) {
HeapRegion* hr = _cleanup_list.remove_head();
assert(hr != NULL, "the list was not empty");
- hr->rem_set()->clear();
+ hr->par_clear();
tmp_free_list.add_as_tail(hr);
// Instead of adding one region at a time to the secondary_free_list,
@@ -2703,12 +2757,16 @@
}
-void ConcurrentMark::clear_marking_state() {
+void ConcurrentMark::clear_marking_state(bool clear_overflow) {
_markStack.setEmpty();
_markStack.clear_overflow();
_regionStack.setEmpty();
_regionStack.clear_overflow();
- clear_has_overflown();
+ if (clear_overflow) {
+ clear_has_overflown();
+ } else {
+ assert(has_overflown(), "pre-condition");
+ }
_finger = _heap_start;
for (int i = 0; i < (int)_max_task_num; ++i) {
@@ -4279,6 +4337,15 @@
}
}
+ // If we are about to wrap up and go into termination, check if we
+ // should raise the overflow flag.
+ if (do_termination && !has_aborted()) {
+ if (_cm->force_overflow()->should_force()) {
+ _cm->set_has_overflown();
+ regular_clock_call();
+ }
+ }
+
// We still haven't aborted. Now, let's try to get into the
// termination protocol.
if (do_termination && !has_aborted()) {
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp Mon May 02 07:08:53 2011 -0700
@@ -316,6 +316,19 @@
void setEmpty() { _index = 0; clear_overflow(); }
};
+class ForceOverflowSettings VALUE_OBJ_CLASS_SPEC {
+private:
+#ifndef PRODUCT
+ uintx _num_remaining;
+ bool _force;
+#endif // !defined(PRODUCT)
+
+public:
+ void init() PRODUCT_RETURN;
+ void update() PRODUCT_RETURN;
+ bool should_force() PRODUCT_RETURN_( return false; );
+};
+
// this will enable a variety of different statistics per GC task
#define _MARKING_STATS_ 0
// this will enable the higher verbose levels
@@ -462,6 +475,9 @@
WorkGang* _parallel_workers;
+ ForceOverflowSettings _force_overflow_conc;
+ ForceOverflowSettings _force_overflow_stw;
+
void weakRefsWork(bool clear_all_soft_refs);
void swapMarkBitMaps();
@@ -470,7 +486,7 @@
// task local ones; should be called during initial mark.
void reset();
// It resets all the marking data structures.
- void clear_marking_state();
+ void clear_marking_state(bool clear_overflow = true);
// It should be called to indicate which phase we're in (concurrent
// mark or remark) and how many threads are currently active.
@@ -547,6 +563,22 @@
void enter_first_sync_barrier(int task_num);
void enter_second_sync_barrier(int task_num);
+ ForceOverflowSettings* force_overflow_conc() {
+ return &_force_overflow_conc;
+ }
+
+ ForceOverflowSettings* force_overflow_stw() {
+ return &_force_overflow_stw;
+ }
+
+ ForceOverflowSettings* force_overflow() {
+ if (concurrent()) {
+ return force_overflow_conc();
+ } else {
+ return force_overflow_stw();
+ }
+ }
+
public:
// Manipulation of the global mark stack.
// Notice that the first mark_stack_push is CAS-based, whereas the
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Mon May 02 07:08:53 2011 -0700
@@ -4961,36 +4961,45 @@
#ifndef PRODUCT
class G1VerifyCardTableCleanup: public HeapRegionClosure {
+ G1CollectedHeap* _g1h;
CardTableModRefBS* _ct_bs;
public:
- G1VerifyCardTableCleanup(CardTableModRefBS* ct_bs)
- : _ct_bs(ct_bs) { }
+ G1VerifyCardTableCleanup(G1CollectedHeap* g1h, CardTableModRefBS* ct_bs)
+ : _g1h(g1h), _ct_bs(ct_bs) { }
virtual bool doHeapRegion(HeapRegion* r) {
- MemRegion mr(r->bottom(), r->end());
if (r->is_survivor()) {
- _ct_bs->verify_dirty_region(mr);
+ _g1h->verify_dirty_region(r);
} else {
- _ct_bs->verify_clean_region(mr);
+ _g1h->verify_not_dirty_region(r);
}
return false;
}
};
+void G1CollectedHeap::verify_not_dirty_region(HeapRegion* hr) {
+ // All of the region should be clean.
+ CardTableModRefBS* ct_bs = (CardTableModRefBS*)barrier_set();
+ MemRegion mr(hr->bottom(), hr->end());
+ ct_bs->verify_not_dirty_region(mr);
+}
+
+void G1CollectedHeap::verify_dirty_region(HeapRegion* hr) {
+ // We cannot guarantee that [bottom(),end()] is dirty. Threads
+ // dirty allocated blocks as they allocate them. The thread that
+ // retires each region and replaces it with a new one will do a
+ // maximal allocation to fill in [pre_dummy_top(),end()] but will
+ // not dirty that area (one less thing to have to do while holding
+ // a lock). So we can only verify that [bottom(),pre_dummy_top()]
+ // is dirty.
+ CardTableModRefBS* ct_bs = (CardTableModRefBS*) barrier_set();
+ MemRegion mr(hr->bottom(), hr->pre_dummy_top());
+ ct_bs->verify_dirty_region(mr);
+}
+
void G1CollectedHeap::verify_dirty_young_list(HeapRegion* head) {
- CardTableModRefBS* ct_bs = (CardTableModRefBS*) (barrier_set());
+ CardTableModRefBS* ct_bs = (CardTableModRefBS*) barrier_set();
for (HeapRegion* hr = head; hr != NULL; hr = hr->get_next_young_region()) {
- // We cannot guarantee that [bottom(),end()] is dirty. Threads
- // dirty allocated blocks as they allocate them. The thread that
- // retires each region and replaces it with a new one will do a
- // maximal allocation to fill in [pre_dummy_top(),end()] but will
- // not dirty that area (one less thing to have to do while holding
- // a lock). So we can only verify that [bottom(),pre_dummy_top()]
- // is dirty. Also note that verify_dirty_region() requires
- // mr.start() and mr.end() to be card aligned and pre_dummy_top()
- // is not guaranteed to be.
- MemRegion mr(hr->bottom(),
- ct_bs->align_to_card_boundary(hr->pre_dummy_top()));
- ct_bs->verify_dirty_region(mr);
+ verify_dirty_region(hr);
}
}
@@ -5033,7 +5042,7 @@
g1_policy()->record_clear_ct_time( elapsed * 1000.0);
#ifndef PRODUCT
if (G1VerifyCTCleanup || VerifyAfterGC) {
- G1VerifyCardTableCleanup cleanup_verifier(ct_bs);
+ G1VerifyCardTableCleanup cleanup_verifier(this, ct_bs);
heap_region_iterate(&cleanup_verifier);
}
#endif
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Mon May 02 07:08:53 2011 -0700
@@ -970,6 +970,8 @@
// The number of regions available for "regular" expansion.
size_t expansion_regions() { return _expansion_regions; }
+ void verify_not_dirty_region(HeapRegion* hr) PRODUCT_RETURN;
+ void verify_dirty_region(HeapRegion* hr) PRODUCT_RETURN;
void verify_dirty_young_list(HeapRegion* head) PRODUCT_RETURN;
void verify_dirty_young_regions() PRODUCT_RETURN;
--- a/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.cpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.cpp Mon May 02 07:08:53 2011 -0700
@@ -157,7 +157,6 @@
void set_try_claimed() { _try_claimed = true; }
void scanCard(size_t index, HeapRegion *r) {
- _cards_done++;
DirtyCardToOopClosure* cl =
r->new_dcto_closure(_oc,
CardTableModRefBS::Precise,
@@ -168,17 +167,14 @@
HeapWord* card_start = _bot_shared->address_for_index(index);
HeapWord* card_end = card_start + G1BlockOffsetSharedArray::N_words;
Space *sp = SharedHeap::heap()->space_containing(card_start);
- MemRegion sm_region;
- if (ParallelGCThreads > 0) {
- // first find the used area
- sm_region = sp->used_region_at_save_marks();
- } else {
- // The closure is not idempotent. We shouldn't look at objects
- // allocated during the GC.
- sm_region = sp->used_region_at_save_marks();
- }
+ MemRegion sm_region = sp->used_region_at_save_marks();
MemRegion mr = sm_region.intersection(MemRegion(card_start,card_end));
- if (!mr.is_empty()) {
+ if (!mr.is_empty() && !_ct_bs->is_card_claimed(index)) {
+ // We make the card as "claimed" lazily (so races are possible
+ // but they're benign), which reduces the number of duplicate
+ // scans (the rsets of the regions in the cset can intersect).
+ _ct_bs->set_card_claimed(index);
+ _cards_done++;
cl->do_MemRegion(mr);
}
}
@@ -199,6 +195,9 @@
HeapRegionRemSet* hrrs = r->rem_set();
if (hrrs->iter_is_complete()) return false; // All done.
if (!_try_claimed && !hrrs->claim_iter()) return false;
+ // If we ever free the collection set concurrently, we should also
+ // clear the card table concurrently therefore we won't need to
+ // add regions of the collection set to the dirty cards region.
_g1h->push_dirty_cards_region(r);
// If we didn't return above, then
// _try_claimed || r->claim_iter()
@@ -230,15 +229,10 @@
_g1h->push_dirty_cards_region(card_region);
}
- // If the card is dirty, then we will scan it during updateRS.
- if (!card_region->in_collection_set() && !_ct_bs->is_card_dirty(card_index)) {
- // We make the card as "claimed" lazily (so races are possible but they're benign),
- // which reduces the number of duplicate scans (the rsets of the regions in the cset
- // can intersect).
- if (!_ct_bs->is_card_claimed(card_index)) {
- _ct_bs->set_card_claimed(card_index);
- scanCard(card_index, card_region);
- }
+ // If the card is dirty, then we will scan it during updateRS.
+ if (!card_region->in_collection_set() &&
+ !_ct_bs->is_card_dirty(card_index)) {
+ scanCard(card_index, card_region);
}
}
if (!_try_claimed) {
@@ -246,8 +240,6 @@
}
return false;
}
- // Set all cards back to clean.
- void cleanup() {_g1h->cleanUpCardTable();}
size_t cards_done() { return _cards_done;}
size_t cards_looked_up() { return _cards;}
};
@@ -566,8 +558,9 @@
update_rs_cl.set_region(r);
HeapWord* stop_point =
r->oops_on_card_seq_iterate_careful(scanRegion,
- &filter_then_update_rs_cset_oop_cl,
- false /* filter_young */);
+ &filter_then_update_rs_cset_oop_cl,
+ false /* filter_young */,
+ NULL /* card_ptr */);
// Since this is performed in the event of an evacuation failure, we
// we shouldn't see a non-null stop point
@@ -735,12 +728,6 @@
(OopClosure*)&mux :
(OopClosure*)&update_rs_oop_cl));
- // Undirty the card.
- *card_ptr = CardTableModRefBS::clean_card_val();
- // We must complete this write before we do any of the reads below.
- OrderAccess::storeload();
- // And process it, being careful of unallocated portions of TLAB's.
-
// The region for the current card may be a young region. The
// current card may have been a card that was evicted from the
// card cache. When the card was inserted into the cache, we had
@@ -749,7 +736,7 @@
// and tagged as young.
//
// We wish to filter out cards for such a region but the current
- // thread, if we're running conucrrently, may "see" the young type
+ // thread, if we're running concurrently, may "see" the young type
// change at any time (so an earlier "is_young" check may pass or
// fail arbitrarily). We tell the iteration code to perform this
// filtering when it has been determined that there has been an actual
@@ -759,7 +746,8 @@
HeapWord* stop_point =
r->oops_on_card_seq_iterate_careful(dirtyRegion,
&filter_then_update_rs_oop_cl,
- filter_young);
+ filter_young,
+ card_ptr);
// If stop_point is non-null, then we encountered an unallocated region
// (perhaps the unfilled portion of a TLAB.) For now, we'll dirty the
--- a/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp Mon May 02 07:08:53 2011 -0700
@@ -311,7 +311,11 @@
\
develop(bool, G1ExitOnExpansionFailure, false, \
"Raise a fatal VM exit out of memory failure in the event " \
- " that heap expansion fails due to running out of swap.")
+ " that heap expansion fails due to running out of swap.") \
+ \
+ develop(uintx, G1ConcMarkForceOverflow, 0, \
+ "The number of times we'll force an overflow during " \
+ "concurrent marking")
G1_FLAGS(DECLARE_DEVELOPER_FLAG, DECLARE_PD_DEVELOPER_FLAG, DECLARE_PRODUCT_FLAG, DECLARE_PD_PRODUCT_FLAG, DECLARE_DIAGNOSTIC_FLAG, DECLARE_EXPERIMENTAL_FLAG, DECLARE_NOTPRODUCT_FLAG, DECLARE_MANAGEABLE_FLAG, DECLARE_PRODUCT_RW_FLAG)
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Mon May 02 07:08:53 2011 -0700
@@ -376,6 +376,17 @@
if (clear_space) clear(SpaceDecorator::Mangle);
}
+void HeapRegion::par_clear() {
+ assert(used() == 0, "the region should have been already cleared");
+ assert(capacity() == (size_t) HeapRegion::GrainBytes,
+ "should be back to normal");
+ HeapRegionRemSet* hrrs = rem_set();
+ hrrs->clear();
+ CardTableModRefBS* ct_bs =
+ (CardTableModRefBS*)G1CollectedHeap::heap()->barrier_set();
+ ct_bs->clear(MemRegion(bottom(), end()));
+}
+
// <PREDICTION>
void HeapRegion::calc_gc_efficiency() {
G1CollectedHeap* g1h = G1CollectedHeap::heap();
@@ -600,7 +611,15 @@
HeapRegion::
oops_on_card_seq_iterate_careful(MemRegion mr,
FilterOutOfRegionClosure* cl,
- bool filter_young) {
+ bool filter_young,
+ jbyte* card_ptr) {
+ // Currently, we should only have to clean the card if filter_young
+ // is true and vice versa.
+ if (filter_young) {
+ assert(card_ptr != NULL, "pre-condition");
+ } else {
+ assert(card_ptr == NULL, "pre-condition");
+ }
G1CollectedHeap* g1h = G1CollectedHeap::heap();
// If we're within a stop-world GC, then we might look at a card in a
@@ -626,6 +645,15 @@
assert(!is_young(), "check value of filter_young");
+ // We can only clean the card here, after we make the decision that
+ // the card is not young. And we only clean the card if we have been
+ // asked to (i.e., card_ptr != NULL).
+ if (card_ptr != NULL) {
+ *card_ptr = CardTableModRefBS::clean_card_val();
+ // We must complete this write before we do any of the reads below.
+ OrderAccess::storeload();
+ }
+
// We used to use "block_start_careful" here. But we're actually happy
// to update the BOT while we do this...
HeapWord* cur = block_start(mr.start());
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Mon May 02 07:08:53 2011 -0700
@@ -584,6 +584,7 @@
// Reset HR stuff to default values.
void hr_clear(bool par, bool clear_space);
+ void par_clear();
void initialize(MemRegion mr, bool clear_space, bool mangle_space);
@@ -802,12 +803,16 @@
HeapWord*
object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl);
- // In this version - if filter_young is true and the region
- // is a young region then we skip the iteration.
+ // filter_young: if true and the region is a young region then we
+ // skip the iteration.
+ // card_ptr: if not NULL, and we decide that the card is not young
+ // and we iterate over it, we'll clean the card before we start the
+ // iteration.
HeapWord*
oops_on_card_seq_iterate_careful(MemRegion mr,
FilterOutOfRegionClosure* cl,
- bool filter_young);
+ bool filter_young,
+ jbyte* card_ptr);
// A version of block start that is guaranteed to find *some* block
// boundary at or before "p", but does not object iteration, and may
--- a/hotspot/src/share/vm/memory/cardTableModRefBS.cpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/memory/cardTableModRefBS.cpp Mon May 02 07:08:53 2011 -0700
@@ -652,43 +652,37 @@
}
#ifndef PRODUCT
-class GuaranteeNotModClosure: public MemRegionClosure {
- CardTableModRefBS* _ct;
-public:
- GuaranteeNotModClosure(CardTableModRefBS* ct) : _ct(ct) {}
- void do_MemRegion(MemRegion mr) {
- jbyte* entry = _ct->byte_for(mr.start());
- guarantee(*entry != CardTableModRefBS::clean_card,
- "Dirty card in region that should be clean");
+void CardTableModRefBS::verify_region(MemRegion mr,
+ jbyte val, bool val_equals) {
+ jbyte* start = byte_for(mr.start());
+ jbyte* end = byte_for(mr.last());
+ bool failures = false;
+ for (jbyte* curr = start; curr <= end; ++curr) {
+ jbyte curr_val = *curr;
+ bool failed = (val_equals) ? (curr_val != val) : (curr_val == val);
+ if (failed) {
+ if (!failures) {
+ tty->cr();
+ tty->print_cr("== CT verification failed: ["PTR_FORMAT","PTR_FORMAT"]");
+ tty->print_cr("== %sexpecting value: %d",
+ (val_equals) ? "" : "not ", val);
+ failures = true;
+ }
+ tty->print_cr("== card "PTR_FORMAT" ["PTR_FORMAT","PTR_FORMAT"], "
+ "val: %d", curr, addr_for(curr),
+ (HeapWord*) (((size_t) addr_for(curr)) + card_size),
+ (int) curr_val);
+ }
}
-};
-
-void CardTableModRefBS::verify_clean_region(MemRegion mr) {
- GuaranteeNotModClosure blk(this);
- non_clean_card_iterate_serial(mr, &blk);
+ guarantee(!failures, "there should not have been any failures");
}
-// To verify a MemRegion is entirely dirty this closure is passed to
-// dirty_card_iterate. If the region is dirty do_MemRegion will be
-// invoked only once with a MemRegion equal to the one being
-// verified.
-class GuaranteeDirtyClosure: public MemRegionClosure {
- CardTableModRefBS* _ct;
- MemRegion _mr;
- bool _result;
-public:
- GuaranteeDirtyClosure(CardTableModRefBS* ct, MemRegion mr)
- : _ct(ct), _mr(mr), _result(false) {}
- void do_MemRegion(MemRegion mr) {
- _result = _mr.equals(mr);
- }
- bool result() const { return _result; }
-};
+void CardTableModRefBS::verify_not_dirty_region(MemRegion mr) {
+ verify_region(mr, dirty_card, false /* val_equals */);
+}
void CardTableModRefBS::verify_dirty_region(MemRegion mr) {
- GuaranteeDirtyClosure blk(this, mr);
- dirty_card_iterate(mr, &blk);
- guarantee(blk.result(), "Non-dirty cards in region that should be dirty");
+ verify_region(mr, dirty_card, true /* val_equals */);
}
#endif
--- a/hotspot/src/share/vm/memory/cardTableModRefBS.hpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/memory/cardTableModRefBS.hpp Mon May 02 07:08:53 2011 -0700
@@ -475,7 +475,10 @@
void verify();
void verify_guard();
- void verify_clean_region(MemRegion mr) PRODUCT_RETURN;
+ // val_equals -> it will check that all cards covered by mr equal val
+ // !val_equals -> it will check that all cards covered by mr do not equal val
+ void verify_region(MemRegion mr, jbyte val, bool val_equals) PRODUCT_RETURN;
+ void verify_not_dirty_region(MemRegion mr) PRODUCT_RETURN;
void verify_dirty_region(MemRegion mr) PRODUCT_RETURN;
static size_t par_chunk_heapword_alignment() {
--- a/hotspot/src/share/vm/memory/modRefBarrierSet.hpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/memory/modRefBarrierSet.hpp Mon May 02 07:08:53 2011 -0700
@@ -100,12 +100,6 @@
// Pass along the argument to the superclass.
ModRefBarrierSet(int max_covered_regions) :
BarrierSet(max_covered_regions) {}
-
-#ifndef PRODUCT
- // Verifies that the given region contains no modified references.
- virtual void verify_clean_region(MemRegion mr) = 0;
-#endif
-
};
#endif // SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
--- a/hotspot/src/share/vm/runtime/arguments.cpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/runtime/arguments.cpp Mon May 02 07:08:53 2011 -0700
@@ -2376,7 +2376,6 @@
_gc_log_filename = strdup(tail);
FLAG_SET_CMDLINE(bool, PrintGC, true);
FLAG_SET_CMDLINE(bool, PrintGCTimeStamps, true);
- FLAG_SET_CMDLINE(bool, TraceClassUnloading, true);
// JNI hooks
} else if (match_option(option, "-Xcheck", &tail)) {
--- a/hotspot/src/share/vm/runtime/os.hpp Fri Apr 29 12:33:39 2011 -0700
+++ b/hotspot/src/share/vm/runtime/os.hpp Mon May 02 07:08:53 2011 -0700
@@ -274,7 +274,7 @@
static char* reserve_memory_special(size_t size, char* addr = NULL,
bool executable = false);
static bool release_memory_special(char* addr, size_t bytes);
- static bool large_page_init();
+ static void large_page_init();
static size_t large_page_size();
static bool can_commit_large_page_memory();
static bool can_execute_large_page_memory();