--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2007 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2007-2010 Sun Microsystems, Inc. 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
@@ -32,11 +32,10 @@
ConcurrentMarkSweepPolicy* as_concurrent_mark_sweep_policy() { return this; }
void initialize_gc_policy_counters();
-#if 1
+
virtual void initialize_size_policy(size_t init_eden_size,
size_t init_promo_size,
size_t init_survivor_size);
-#endif
// Returns true if the incremental mode is enabled.
virtual bool has_soft_ended_eden();
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -1815,8 +1815,19 @@
do_compaction_work(clear_all_soft_refs);
// Has the GC time limit been exceeded?
- check_gc_time_limit();
-
+ DefNewGeneration* young_gen = _young_gen->as_DefNewGeneration();
+ size_t max_eden_size = young_gen->max_capacity() -
+ young_gen->to()->capacity() -
+ young_gen->from()->capacity();
+ GenCollectedHeap* gch = GenCollectedHeap::heap();
+ GCCause::Cause gc_cause = gch->gc_cause();
+ size_policy()->check_gc_overhead_limit(_young_gen->used(),
+ young_gen->eden()->used(),
+ _cmsGen->max_capacity(),
+ max_eden_size,
+ full,
+ gc_cause,
+ gch->collector_policy());
} else {
do_mark_sweep_work(clear_all_soft_refs, first_state,
should_start_over);
@@ -1828,55 +1839,6 @@
return;
}
-void CMSCollector::check_gc_time_limit() {
-
- // Ignore explicit GC's. Exiting here does not set the flag and
- // does not reset the count. Updating of the averages for system
- // GC's is still controlled by UseAdaptiveSizePolicyWithSystemGC.
- GCCause::Cause gc_cause = GenCollectedHeap::heap()->gc_cause();
- if (GCCause::is_user_requested_gc(gc_cause) ||
- GCCause::is_serviceability_requested_gc(gc_cause)) {
- return;
- }
-
- // Calculate the fraction of the CMS generation was freed during
- // the last collection.
- // Only consider the STW compacting cost for now.
- //
- // Note that the gc time limit test only works for the collections
- // of the young gen + tenured gen and not for collections of the
- // permanent gen. That is because the calculation of the space
- // freed by the collection is the free space in the young gen +
- // tenured gen.
-
- double fraction_free =
- ((double)_cmsGen->free())/((double)_cmsGen->max_capacity());
- if ((100.0 * size_policy()->compacting_gc_cost()) >
- ((double) GCTimeLimit) &&
- ((fraction_free * 100) < GCHeapFreeLimit)) {
- size_policy()->inc_gc_time_limit_count();
- if (UseGCOverheadLimit &&
- (size_policy()->gc_time_limit_count() >
- AdaptiveSizePolicyGCTimeLimitThreshold)) {
- size_policy()->set_gc_time_limit_exceeded(true);
- // Avoid consecutive OOM due to the gc time limit by resetting
- // the counter.
- size_policy()->reset_gc_time_limit_count();
- if (PrintGCDetails) {
- gclog_or_tty->print_cr(" GC is exceeding overhead limit "
- "of %d%%", GCTimeLimit);
- }
- } else {
- if (PrintGCDetails) {
- gclog_or_tty->print_cr(" GC would exceed overhead limit "
- "of %d%%", GCTimeLimit);
- }
- }
- } else {
- size_policy()->reset_gc_time_limit_count();
- }
-}
-
// Resize the perm generation and the tenured generation
// after obtaining the free list locks for the
// two generations.
@@ -6182,6 +6144,11 @@
}
curAddr = chunk.end();
}
+ // A successful mostly concurrent collection has been done.
+ // Because only the full (i.e., concurrent mode failure) collections
+ // are being measured for gc overhead limits, clean the "near" flag
+ // and count.
+ sp->reset_gc_overhead_limit_count();
_collectorState = Idling;
} else {
// already have the lock
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -570,10 +570,6 @@
ConcurrentMarkSweepPolicy* _collector_policy;
ConcurrentMarkSweepPolicy* collector_policy() { return _collector_policy; }
- // Check whether the gc time limit has been
- // exceeded and set the size policy flag
- // appropriately.
- void check_gc_time_limit();
// XXX Move these to CMSStats ??? FIX ME !!!
elapsedTimer _inter_sweep_timer; // time between sweeps
elapsedTimer _intra_sweep_timer; // time _in_ sweeps
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -69,9 +69,9 @@
G1CollectorPolicy* g1p = g1h->g1_policy();
if (g1p->adaptive_young_list_length()) {
int regions_visited = 0;
- g1h->young_list_rs_length_sampling_init();
- while (g1h->young_list_rs_length_sampling_more()) {
- g1h->young_list_rs_length_sampling_next();
+ g1h->young_list()->rs_length_sampling_init();
+ while (g1h->young_list()->rs_length_sampling_more()) {
+ g1h->young_list()->rs_length_sampling_next();
++regions_visited;
// we try to yield every time we visit 10 regions
@@ -162,6 +162,7 @@
if (_worker_id >= cg1r()->worker_thread_num()) {
run_young_rs_sampling();
terminate();
+ return;
}
_vtime_start = os::elapsedVTime();
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -767,7 +767,8 @@
_has_aborted = false;
if (G1PrintReachableAtInitialMark) {
- print_reachable(true, "before");
+ print_reachable("at-cycle-start",
+ true /* use_prev_marking */, true /* all */);
}
// Initialise marking structures. This has to be done in a STW phase.
@@ -1979,19 +1980,21 @@
#ifndef PRODUCT
-class ReachablePrinterOopClosure: public OopClosure {
+class PrintReachableOopClosure: public OopClosure {
private:
G1CollectedHeap* _g1h;
CMBitMapRO* _bitmap;
outputStream* _out;
bool _use_prev_marking;
+ bool _all;
public:
- ReachablePrinterOopClosure(CMBitMapRO* bitmap,
- outputStream* out,
- bool use_prev_marking) :
+ PrintReachableOopClosure(CMBitMapRO* bitmap,
+ outputStream* out,
+ bool use_prev_marking,
+ bool all) :
_g1h(G1CollectedHeap::heap()),
- _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
+ _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking), _all(all) { }
void do_oop(narrowOop* p) { do_oop_work(p); }
void do_oop( oop* p) { do_oop_work(p); }
@@ -2001,9 +2004,11 @@
const char* str = NULL;
const char* str2 = "";
- if (!_g1h->is_in_g1_reserved(obj))
- str = "outside G1 reserved";
- else {
+ if (obj == NULL) {
+ str = "";
+ } else if (!_g1h->is_in_g1_reserved(obj)) {
+ str = " O";
+ } else {
HeapRegion* hr = _g1h->heap_region_containing(obj);
guarantee(hr != NULL, "invariant");
bool over_tams = false;
@@ -2012,74 +2017,67 @@
} else {
over_tams = hr->obj_allocated_since_next_marking(obj);
}
+ bool marked = _bitmap->isMarked((HeapWord*) obj);
if (over_tams) {
- str = "over TAMS";
- if (_bitmap->isMarked((HeapWord*) obj)) {
+ str = " >";
+ if (marked) {
str2 = " AND MARKED";
}
- } else if (_bitmap->isMarked((HeapWord*) obj)) {
- str = "marked";
+ } else if (marked) {
+ str = " M";
} else {
- str = "#### NOT MARKED ####";
+ str = " NOT";
}
}
- _out->print_cr(" "PTR_FORMAT" contains "PTR_FORMAT" %s%s",
+ _out->print_cr(" "PTR_FORMAT": "PTR_FORMAT"%s%s",
p, (void*) obj, str, str2);
}
};
-class ReachablePrinterClosure: public BitMapClosure {
+class PrintReachableObjectClosure : public ObjectClosure {
private:
CMBitMapRO* _bitmap;
outputStream* _out;
bool _use_prev_marking;
+ bool _all;
+ HeapRegion* _hr;
public:
- ReachablePrinterClosure(CMBitMapRO* bitmap,
- outputStream* out,
- bool use_prev_marking) :
- _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
-
- bool do_bit(size_t offset) {
- HeapWord* addr = _bitmap->offsetToHeapWord(offset);
- ReachablePrinterOopClosure oopCl(_bitmap, _out, _use_prev_marking);
-
- _out->print_cr(" obj "PTR_FORMAT", offset %10d (marked)", addr, offset);
- oop(addr)->oop_iterate(&oopCl);
- _out->print_cr("");
-
- return true;
+ PrintReachableObjectClosure(CMBitMapRO* bitmap,
+ outputStream* out,
+ bool use_prev_marking,
+ bool all,
+ HeapRegion* hr) :
+ _bitmap(bitmap), _out(out),
+ _use_prev_marking(use_prev_marking), _all(all), _hr(hr) { }
+
+ void do_object(oop o) {
+ bool over_tams;
+ if (_use_prev_marking) {
+ over_tams = _hr->obj_allocated_since_prev_marking(o);
+ } else {
+ over_tams = _hr->obj_allocated_since_next_marking(o);
+ }
+ bool marked = _bitmap->isMarked((HeapWord*) o);
+ bool print_it = _all || over_tams || marked;
+
+ if (print_it) {
+ _out->print_cr(" "PTR_FORMAT"%s",
+ o, (over_tams) ? " >" : (marked) ? " M" : "");
+ PrintReachableOopClosure oopCl(_bitmap, _out, _use_prev_marking, _all);
+ o->oop_iterate(&oopCl);
+ }
}
};
-class ObjInRegionReachablePrinterClosure : public ObjectClosure {
+class PrintReachableRegionClosure : public HeapRegionClosure {
private:
CMBitMapRO* _bitmap;
outputStream* _out;
bool _use_prev_marking;
-
-public:
- ObjInRegionReachablePrinterClosure(CMBitMapRO* bitmap,
- outputStream* out,
- bool use_prev_marking) :
- _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
-
- void do_object(oop o) {
- ReachablePrinterOopClosure oopCl(_bitmap, _out, _use_prev_marking);
-
- _out->print_cr(" obj "PTR_FORMAT" (over TAMS)", (void*) o);
- o->oop_iterate(&oopCl);
- _out->print_cr("");
- }
-};
-
-class RegionReachablePrinterClosure : public HeapRegionClosure {
-private:
- CMBitMapRO* _bitmap;
- outputStream* _out;
- bool _use_prev_marking;
+ bool _all;
public:
bool doHeapRegion(HeapRegion* hr) {
@@ -2094,22 +2092,35 @@
}
_out->print_cr("** ["PTR_FORMAT", "PTR_FORMAT"] top: "PTR_FORMAT" "
"TAMS: "PTR_FORMAT, b, e, t, p);
- _out->print_cr("");
-
- ObjInRegionReachablePrinterClosure ocl(_bitmap, _out, _use_prev_marking);
- hr->object_iterate_mem_careful(MemRegion(p, t), &ocl);
+ _out->cr();
+
+ HeapWord* from = b;
+ HeapWord* to = t;
+
+ if (to > from) {
+ _out->print_cr("Objects in ["PTR_FORMAT", "PTR_FORMAT"]", from, to);
+ _out->cr();
+ PrintReachableObjectClosure ocl(_bitmap, _out,
+ _use_prev_marking, _all, hr);
+ hr->object_iterate_mem_careful(MemRegion(from, to), &ocl);
+ _out->cr();
+ }
return false;
}
- RegionReachablePrinterClosure(CMBitMapRO* bitmap,
- outputStream* out,
- bool use_prev_marking) :
- _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
+ PrintReachableRegionClosure(CMBitMapRO* bitmap,
+ outputStream* out,
+ bool use_prev_marking,
+ bool all) :
+ _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking), _all(all) { }
};
-void ConcurrentMark::print_reachable(bool use_prev_marking, const char* str) {
- gclog_or_tty->print_cr("== Doing reachable object dump... ");
+void ConcurrentMark::print_reachable(const char* str,
+ bool use_prev_marking,
+ bool all) {
+ gclog_or_tty->cr();
+ gclog_or_tty->print_cr("== Doing heap dump... ");
if (G1PrintReachableBaseFile == NULL) {
gclog_or_tty->print_cr(" #### error: no base file defined");
@@ -2144,19 +2155,14 @@
out->print_cr("-- USING %s", (use_prev_marking) ? "PTAMS" : "NTAMS");
out->cr();
- RegionReachablePrinterClosure rcl(bitmap, out, use_prev_marking);
- out->print_cr("--- ITERATING OVER REGIONS WITH TAMS < TOP");
- out->cr();
- _g1h->heap_region_iterate(&rcl);
+ out->print_cr("--- ITERATING OVER REGIONS");
out->cr();
-
- ReachablePrinterClosure cl(bitmap, out, use_prev_marking);
- out->print_cr("--- ITERATING OVER MARKED OBJECTS ON THE BITMAP");
- out->cr();
- bitmap->iterate(&cl);
+ PrintReachableRegionClosure rcl(bitmap, out, use_prev_marking, all);
+ _g1h->heap_region_iterate(&rcl);
out->cr();
gclog_or_tty->print_cr(" done");
+ gclog_or_tty->flush();
}
#endif // PRODUCT
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -652,11 +652,24 @@
// we do nothing.
void markAndGrayObjectIfNecessary(oop p);
- // This iterates over the marking bitmap (either prev or next) and
- // prints out all objects that are marked on the bitmap and indicates
- // whether what they point to is also marked or not. It also iterates
- // the objects over TAMS (either prev or next).
- void print_reachable(bool use_prev_marking, const char* str);
+ // It iterates over the heap and for each object it comes across it
+ // will dump the contents of its reference fields, as well as
+ // liveness information for the object and its referents. The dump
+ // will be written to a file with the following name:
+ // G1PrintReachableBaseFile + "." + str. use_prev_marking decides
+ // whether the prev (use_prev_marking == true) or next
+ // (use_prev_marking == false) marking information will be used to
+ // determine the liveness of each object / referent. If all is true,
+ // all objects in the heap will be dumped, otherwise only the live
+ // ones. In the dump the following symbols / abbreviations are used:
+ // M : an explicitly live object (its bitmap bit is set)
+ // > : an implicitly live object (over tams)
+ // O : an object outside the G1 heap (typically: in the perm gen)
+ // NOT : a reference field whose referent is not live
+ // AND MARKED : indicates that an object is both explicitly and
+ // implicitly live (it should be one or the other, not both)
+ void print_reachable(const char* str,
+ bool use_prev_marking, bool all) PRODUCT_RETURN;
// Clear the next marking bitmap (will be called concurrently).
void clearNextBitmap();
@@ -720,6 +733,19 @@
// to determine whether any heap regions are located above the finger.
void registerCSetRegion(HeapRegion* hr);
+ // Registers the maximum region-end associated with a set of
+ // regions with CM. Again this is used to determine whether any
+ // heap regions are located above the finger.
+ void register_collection_set_finger(HeapWord* max_finger) {
+ // max_finger is the highest heap region end of the regions currently
+ // contained in the collection set. If this value is larger than
+ // _min_finger then we need to gray objects.
+ // This routine is like registerCSetRegion but for an entire
+ // collection of regions.
+ if (max_finger > _min_finger)
+ _should_gray_objects = true;
+ }
+
// Returns "true" if at least one mark has been completed.
bool at_least_one_mark_complete() { return _at_least_one_mark_complete; }
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -30,7 +30,7 @@
// turn it on so that the contents of the young list (scan-only /
// to-be-collected) are printed at "strategic" points before / during
// / after the collection --- this is useful for debugging
-#define SCAN_ONLY_VERBOSE 0
+#define YOUNG_LIST_VERBOSE 0
// CURRENT STATUS
// This file is under construction. Search for "FIXME".
@@ -133,8 +133,7 @@
YoungList::YoungList(G1CollectedHeap* g1h)
: _g1h(g1h), _head(NULL),
- _scan_only_head(NULL), _scan_only_tail(NULL), _curr_scan_only(NULL),
- _length(0), _scan_only_length(0),
+ _length(0),
_last_sampled_rs_lengths(0),
_survivor_head(NULL), _survivor_tail(NULL), _survivor_length(0)
{
@@ -166,48 +165,6 @@
++_survivor_length;
}
-HeapRegion* YoungList::pop_region() {
- while (_head != NULL) {
- assert( length() > 0, "list should not be empty" );
- HeapRegion* ret = _head;
- _head = ret->get_next_young_region();
- ret->set_next_young_region(NULL);
- --_length;
- assert(ret->is_young(), "region should be very young");
-
- // Replace 'Survivor' region type with 'Young'. So the region will
- // be treated as a young region and will not be 'confused' with
- // newly created survivor regions.
- if (ret->is_survivor()) {
- ret->set_young();
- }
-
- if (!ret->is_scan_only()) {
- return ret;
- }
-
- // scan-only, we'll add it to the scan-only list
- if (_scan_only_tail == NULL) {
- guarantee( _scan_only_head == NULL, "invariant" );
-
- _scan_only_head = ret;
- _curr_scan_only = ret;
- } else {
- guarantee( _scan_only_head != NULL, "invariant" );
- _scan_only_tail->set_next_young_region(ret);
- }
- guarantee( ret->get_next_young_region() == NULL, "invariant" );
- _scan_only_tail = ret;
-
- // no need to be tagged as scan-only any more
- ret->set_young();
-
- ++_scan_only_length;
- }
- assert( length() == 0, "list should be empty" );
- return NULL;
-}
-
void YoungList::empty_list(HeapRegion* list) {
while (list != NULL) {
HeapRegion* next = list->get_next_young_region();
@@ -225,12 +182,6 @@
_head = NULL;
_length = 0;
- empty_list(_scan_only_head);
- _scan_only_head = NULL;
- _scan_only_tail = NULL;
- _scan_only_length = 0;
- _curr_scan_only = NULL;
-
empty_list(_survivor_head);
_survivor_head = NULL;
_survivor_tail = NULL;
@@ -248,11 +199,11 @@
HeapRegion* curr = _head;
HeapRegion* last = NULL;
while (curr != NULL) {
- if (!curr->is_young() || curr->is_scan_only()) {
+ if (!curr->is_young()) {
gclog_or_tty->print_cr("### YOUNG REGION "PTR_FORMAT"-"PTR_FORMAT" "
- "incorrectly tagged (%d, %d)",
+ "incorrectly tagged (y: %d, surv: %d)",
curr->bottom(), curr->end(),
- curr->is_young(), curr->is_scan_only());
+ curr->is_young(), curr->is_survivor());
ret = false;
}
++length;
@@ -267,47 +218,10 @@
length, _length);
}
- bool scan_only_ret = true;
- length = 0;
- curr = _scan_only_head;
- last = NULL;
- while (curr != NULL) {
- if (!curr->is_young() || curr->is_scan_only()) {
- gclog_or_tty->print_cr("### SCAN-ONLY REGION "PTR_FORMAT"-"PTR_FORMAT" "
- "incorrectly tagged (%d, %d)",
- curr->bottom(), curr->end(),
- curr->is_young(), curr->is_scan_only());
- scan_only_ret = false;
- }
- ++length;
- last = curr;
- curr = curr->get_next_young_region();
- }
- scan_only_ret = scan_only_ret && (length == _scan_only_length);
-
- if ( (last != _scan_only_tail) ||
- (_scan_only_head == NULL && _scan_only_tail != NULL) ||
- (_scan_only_head != NULL && _scan_only_tail == NULL) ) {
- gclog_or_tty->print_cr("## _scan_only_tail is set incorrectly");
- scan_only_ret = false;
- }
-
- if (_curr_scan_only != NULL && _curr_scan_only != _scan_only_head) {
- gclog_or_tty->print_cr("### _curr_scan_only is set incorrectly");
- scan_only_ret = false;
- }
-
- if (!scan_only_ret) {
- gclog_or_tty->print_cr("### SCAN-ONLY LIST seems not well formed!");
- gclog_or_tty->print_cr("### list has %d entries, _scan_only_length is %d",
- length, _scan_only_length);
- }
-
- return ret && scan_only_ret;
+ return ret;
}
-bool YoungList::check_list_empty(bool ignore_scan_only_list,
- bool check_sample) {
+bool YoungList::check_list_empty(bool check_sample) {
bool ret = true;
if (_length != 0) {
@@ -327,28 +241,7 @@
gclog_or_tty->print_cr("### YOUNG LIST does not seem empty");
}
- if (ignore_scan_only_list)
- return ret;
-
- bool scan_only_ret = true;
- if (_scan_only_length != 0) {
- gclog_or_tty->print_cr("### SCAN-ONLY LIST should have 0 length, not %d",
- _scan_only_length);
- scan_only_ret = false;
- }
- if (_scan_only_head != NULL) {
- gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL head");
- scan_only_ret = false;
- }
- if (_scan_only_tail != NULL) {
- gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL tail");
- scan_only_ret = false;
- }
- if (!scan_only_ret) {
- gclog_or_tty->print_cr("### SCAN-ONLY LIST does not seem empty");
- }
-
- return ret && scan_only_ret;
+ return ret;
}
void
@@ -365,7 +258,18 @@
void
YoungList::rs_length_sampling_next() {
assert( _curr != NULL, "invariant" );
- _sampled_rs_lengths += _curr->rem_set()->occupied();
+ size_t rs_length = _curr->rem_set()->occupied();
+
+ _sampled_rs_lengths += rs_length;
+
+ // The current region may not yet have been added to the
+ // incremental collection set (it gets added when it is
+ // retired as the current allocation region).
+ if (_curr->in_collection_set()) {
+ // Update the collection set policy information for this region
+ _g1h->g1_policy()->update_incremental_cset_info(_curr, rs_length);
+ }
+
_curr = _curr->get_next_young_region();
if (_curr == NULL) {
_last_sampled_rs_lengths = _sampled_rs_lengths;
@@ -375,54 +279,46 @@
void
YoungList::reset_auxilary_lists() {
- // We could have just "moved" the scan-only list to the young list.
- // However, the scan-only list is ordered according to the region
- // age in descending order, so, by moving one entry at a time, we
- // ensure that it is recreated in ascending order.
-
guarantee( is_empty(), "young list should be empty" );
assert(check_list_well_formed(), "young list should be well formed");
// Add survivor regions to SurvRateGroup.
_g1h->g1_policy()->note_start_adding_survivor_regions();
_g1h->g1_policy()->finished_recalculating_age_indexes(true /* is_survivors */);
+
for (HeapRegion* curr = _survivor_head;
curr != NULL;
curr = curr->get_next_young_region()) {
_g1h->g1_policy()->set_region_survivors(curr);
+
+ // 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);
}
_g1h->g1_policy()->note_stop_adding_survivor_regions();
+ _head = _survivor_head;
+ _length = _survivor_length;
if (_survivor_head != NULL) {
- _head = _survivor_head;
- _length = _survivor_length + _scan_only_length;
- _survivor_tail->set_next_young_region(_scan_only_head);
- } else {
- _head = _scan_only_head;
- _length = _scan_only_length;
- }
-
- for (HeapRegion* curr = _scan_only_head;
- curr != NULL;
- curr = curr->get_next_young_region()) {
- curr->recalculate_age_in_surv_rate_group();
- }
- _scan_only_head = NULL;
- _scan_only_tail = NULL;
- _scan_only_length = 0;
- _curr_scan_only = NULL;
-
- _survivor_head = NULL;
- _survivor_tail = NULL;
- _survivor_length = 0;
+ assert(_survivor_tail != NULL, "cause it shouldn't be");
+ assert(_survivor_length > 0, "invariant");
+ _survivor_tail->set_next_young_region(NULL);
+ }
+
+ // Don't clear the survivor list handles until the start of
+ // the next evacuation pause - we need it in order to re-tag
+ // the survivor regions from this evacuation pause as 'young'
+ // at the start of the next.
+
_g1h->g1_policy()->finished_recalculating_age_indexes(false /* is_survivors */);
assert(check_list_well_formed(), "young list should be well formed");
}
void YoungList::print() {
- HeapRegion* lists[] = {_head, _scan_only_head, _survivor_head};
- const char* names[] = {"YOUNG", "SCAN-ONLY", "SURVIVOR"};
+ HeapRegion* lists[] = {_head, _survivor_head};
+ const char* names[] = {"YOUNG", "SURVIVOR"};
for (unsigned int list = 0; list < ARRAY_SIZE(lists); ++list) {
gclog_or_tty->print_cr("%s LIST CONTENTS", names[list]);
@@ -431,7 +327,7 @@
gclog_or_tty->print_cr(" empty");
while (curr != NULL) {
gclog_or_tty->print_cr(" [%08x-%08x], t: %08x, P: %08x, N: %08x, C: %08x, "
- "age: %4d, y: %d, s-o: %d, surv: %d",
+ "age: %4d, y: %d, surv: %d",
curr->bottom(), curr->end(),
curr->top(),
curr->prev_top_at_mark_start(),
@@ -439,7 +335,6 @@
curr->top_at_conc_mark_count(),
curr->age_in_surv_rate_group_cond(),
curr->is_young(),
- curr->is_scan_only(),
curr->is_survivor());
curr = curr->get_next_young_region();
}
@@ -707,6 +602,12 @@
// region below.
if (_cur_alloc_region != NULL) {
// We're finished with the _cur_alloc_region.
+ // As we're builing (at least the young portion) of the collection
+ // set incrementally we'll add the current allocation region to
+ // the collection set here.
+ if (_cur_alloc_region->is_young()) {
+ g1_policy()->add_region_to_incremental_cset_lhs(_cur_alloc_region);
+ }
_summary_bytes_used += _cur_alloc_region->used();
_cur_alloc_region = NULL;
}
@@ -820,6 +721,12 @@
_free_regions++;
free_region(_cur_alloc_region);
} else {
+ // As we're builing (at least the young portion) of the collection
+ // set incrementally we'll add the current allocation region to
+ // the collection set here.
+ if (_cur_alloc_region->is_young()) {
+ g1_policy()->add_region_to_incremental_cset_lhs(_cur_alloc_region);
+ }
_summary_bytes_used += _cur_alloc_region->used();
}
_cur_alloc_region = NULL;
@@ -913,20 +820,25 @@
}
if (full && DisableExplicitGC) {
- gclog_or_tty->print("\n\n\nDisabling Explicit GC\n\n\n");
return;
}
assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
assert(Thread::current() == VMThread::vm_thread(), "should be in vm thread");
+ const bool do_clear_all_soft_refs = clear_all_soft_refs ||
+ collector_policy()->should_clear_all_soft_refs();
+
+ ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
+
{
IsGCActiveMark x;
// Timing
gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
- TraceTime t(full ? "Full GC (System.gc())" : "Full GC", PrintGC, true, gclog_or_tty);
+ TraceTime t(full ? "Full GC (System.gc())" : "Full GC",
+ PrintGC, true, gclog_or_tty);
TraceMemoryManagerStats tms(true /* fullGC */);
@@ -970,6 +882,15 @@
g1_rem_set()->as_HRInto_G1RemSet()->cleanupHRRS();
tear_down_region_lists();
set_used_regions_to_need_zero_fill();
+
+ // We may have added regions to the current incremental collection
+ // set between the last GC or pause and now. We need to clear the
+ // incremental collection set and then start rebuilding it afresh
+ // after this full GC.
+ abandon_collection_set(g1_policy()->inc_cset_head());
+ g1_policy()->clear_incremental_cset();
+ g1_policy()->stop_incremental_cset_building();
+
if (g1_policy()->in_young_gc_mode()) {
empty_young_list();
g1_policy()->set_full_young_gcs(true);
@@ -985,12 +906,12 @@
ReferenceProcessorIsAliveMutator rp_is_alive_null(ref_processor(), NULL);
ref_processor()->enable_discovery();
- ref_processor()->setup_policy(clear_all_soft_refs);
+ ref_processor()->setup_policy(do_clear_all_soft_refs);
// Do collection work
{
HandleMark hm; // Discard invalid handles created during gc
- G1MarkSweep::invoke_at_safepoint(ref_processor(), clear_all_soft_refs);
+ G1MarkSweep::invoke_at_safepoint(ref_processor(), do_clear_all_soft_refs);
}
// Because freeing humongous regions may have added some unclean
// regions, it is necessary to tear down again before rebuilding.
@@ -1053,6 +974,15 @@
perm()->compute_new_size();
}
+ // Start a new incremental collection set for the next pause
+ assert(g1_policy()->collection_set() == NULL, "must be");
+ g1_policy()->start_incremental_cset_building();
+
+ // Clear the _cset_fast_test bitmap in anticipation of adding
+ // regions to the incremental collection set for the next
+ // evacuation pause.
+ clear_cset_fast_test();
+
double end = os::elapsedTime();
g1_policy()->record_full_collection_end();
@@ -1071,7 +1001,9 @@
if (g1_policy()->in_young_gc_mode()) {
_young_list->reset_sampled_info();
- assert( check_young_list_empty(false, false),
+ // At this point there should be no regions in the
+ // entire heap tagged as young.
+ assert( check_young_list_empty(true /* check_heap */),
"young list should be empty at this point");
}
@@ -1208,6 +1140,9 @@
return result;
}
+ assert(!collector_policy()->should_clear_all_soft_refs(),
+ "Flag should have been handled and cleared prior to this point");
+
// What else? We might try synchronous finalization later. If the total
// space available is large enough for the allocation, then a more
// complete compaction phase than we've tried so far might be
@@ -1565,6 +1500,20 @@
_g1h = this;
+ _in_cset_fast_test_length = max_regions();
+ _in_cset_fast_test_base = NEW_C_HEAP_ARRAY(bool, _in_cset_fast_test_length);
+
+ // We're biasing _in_cset_fast_test to avoid subtracting the
+ // beginning of the heap every time we want to index; basically
+ // it's the same with what we do with the card table.
+ _in_cset_fast_test = _in_cset_fast_test_base -
+ ((size_t) _g1_reserved.start() >> HeapRegion::LogOfHRGrainBytes);
+
+ // Clear the _cset_fast_test bitmap in anticipation of adding
+ // regions to the incremental collection set for the first
+ // evacuation pause.
+ clear_cset_fast_test();
+
// Create the ConcurrentMark data structure and thread.
// (Must do this late, so that "max_regions" is defined.)
_cm = new ConcurrentMark(heap_rs, (int) max_regions());
@@ -2185,8 +2134,10 @@
assert(o != NULL, "Huh?");
if (!_g1h->is_obj_dead_cond(o, _use_prev_marking)) {
o->oop_iterate(&isLive);
- if (!_hr->obj_allocated_since_prev_marking(o))
- _live_bytes += (o->size() * HeapWordSize);
+ if (!_hr->obj_allocated_since_prev_marking(o)) {
+ size_t obj_size = o->size(); // Make sure we don't overflow
+ _live_bytes += (obj_size * HeapWordSize);
+ }
}
}
size_t live_bytes() { return _live_bytes; }
@@ -2388,8 +2339,8 @@
print_on(gclog_or_tty, true /* extended */);
gclog_or_tty->print_cr("");
if (VerifyDuringGC && G1VerifyDuringGCPrintReachable) {
- concurrent_mark()->print_reachable(use_prev_marking,
- "failed-verification");
+ concurrent_mark()->print_reachable("at-verification-failure",
+ use_prev_marking, false /* all */);
}
gclog_or_tty->flush();
}
@@ -2741,25 +2692,19 @@
double start_time_sec = os::elapsedTime();
size_t start_used_bytes = used();
+#if YOUNG_LIST_VERBOSE
+ gclog_or_tty->print_cr("\nBefore recording pause start.\nYoung_list:");
+ _young_list->print();
+ g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
+#endif // YOUNG_LIST_VERBOSE
+
g1_policy()->record_collection_pause_start(start_time_sec,
start_used_bytes);
- guarantee(_in_cset_fast_test == NULL, "invariant");
- guarantee(_in_cset_fast_test_base == NULL, "invariant");
- _in_cset_fast_test_length = max_regions();
- _in_cset_fast_test_base =
- NEW_C_HEAP_ARRAY(bool, _in_cset_fast_test_length);
- memset(_in_cset_fast_test_base, false,
- _in_cset_fast_test_length * sizeof(bool));
- // We're biasing _in_cset_fast_test to avoid subtracting the
- // beginning of the heap every time we want to index; basically
- // it's the same with what we do with the card table.
- _in_cset_fast_test = _in_cset_fast_test_base -
- ((size_t) _g1_reserved.start() >> HeapRegion::LogOfHRGrainBytes);
-
-#if SCAN_ONLY_VERBOSE
+#if YOUNG_LIST_VERBOSE
+ gclog_or_tty->print_cr("\nAfter recording pause start.\nYoung_list:");
_young_list->print();
-#endif // SCAN_ONLY_VERBOSE
+#endif // YOUNG_LIST_VERBOSE
if (g1_policy()->during_initial_mark_pause()) {
concurrent_mark()->checkpointRootsInitialPre();
@@ -2786,12 +2731,15 @@
if (mark_in_progress())
concurrent_mark()->newCSet();
- // Now choose the CS.
- g1_policy()->choose_collection_set();
-
- // We may abandon a pause if we find no region that will fit in the MMU
- // pause.
- bool abandoned = (g1_policy()->collection_set() == NULL);
+#if YOUNG_LIST_VERBOSE
+ gclog_or_tty->print_cr("\nBefore choosing collection set.\nYoung_list:");
+ _young_list->print();
+ g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
+#endif // YOUNG_LIST_VERBOSE
+
+ // Now choose the CS. We may abandon a pause if we find no
+ // region that will fit in the MMU pause.
+ bool abandoned = g1_policy()->choose_collection_set();
// Nothing to do if we were unable to choose a collection set.
if (!abandoned) {
@@ -2809,40 +2757,64 @@
// Actually do the work...
evacuate_collection_set();
+
free_collection_set(g1_policy()->collection_set());
g1_policy()->clear_collection_set();
- FREE_C_HEAP_ARRAY(bool, _in_cset_fast_test_base);
- // this is more for peace of mind; we're nulling them here and
- // we're expecting them to be null at the beginning of the next GC
- _in_cset_fast_test = NULL;
- _in_cset_fast_test_base = NULL;
-
cleanup_surviving_young_words();
+ // Start a new incremental collection set for the next pause.
+ g1_policy()->start_incremental_cset_building();
+
+ // Clear the _cset_fast_test bitmap in anticipation of adding
+ // regions to the incremental collection set for the next
+ // evacuation pause.
+ clear_cset_fast_test();
+
if (g1_policy()->in_young_gc_mode()) {
_young_list->reset_sampled_info();
- assert(check_young_list_empty(true),
- "young list should be empty");
-
-#if SCAN_ONLY_VERBOSE
+
+ // Don't check the whole heap at this point as the
+ // GC alloc regions from this pause have been tagged
+ // as survivors and moved on to the survivor list.
+ // Survivor regions will fail the !is_young() check.
+ assert(check_young_list_empty(false /* check_heap */),
+ "young list should be empty");
+
+#if YOUNG_LIST_VERBOSE
+ gclog_or_tty->print_cr("Before recording survivors.\nYoung List:");
_young_list->print();
-#endif // SCAN_ONLY_VERBOSE
+#endif // YOUNG_LIST_VERBOSE
g1_policy()->record_survivor_regions(_young_list->survivor_length(),
_young_list->first_survivor_region(),
_young_list->last_survivor_region());
+
_young_list->reset_auxilary_lists();
}
} else {
- if (_in_cset_fast_test != NULL) {
- assert(_in_cset_fast_test_base != NULL, "Since _in_cset_fast_test isn't");
- FREE_C_HEAP_ARRAY(bool, _in_cset_fast_test_base);
- // this is more for peace of mind; we're nulling them here and
- // we're expecting them to be null at the beginning of the next GC
- _in_cset_fast_test = NULL;
- _in_cset_fast_test_base = NULL;
- }
+ // We have abandoned the current collection. This can only happen
+ // if we're not doing young or partially young collections, and
+ // we didn't find an old region that we're able to collect within
+ // the allowed time.
+
+ assert(g1_policy()->collection_set() == NULL, "should be");
+ assert(_young_list->length() == 0, "because it should be");
+
+ // This should be a no-op.
+ abandon_collection_set(g1_policy()->inc_cset_head());
+
+ g1_policy()->clear_incremental_cset();
+ g1_policy()->stop_incremental_cset_building();
+
+ // Start a new incremental collection set for the next pause.
+ g1_policy()->start_incremental_cset_building();
+
+ // Clear the _cset_fast_test bitmap in anticipation of adding
+ // regions to the incremental collection set for the next
+ // evacuation pause.
+ clear_cset_fast_test();
+
// This looks confusing, because the DPT should really be empty
// at this point -- since we have not done any collection work,
// there should not be any derived pointers in the table to update;
@@ -2876,9 +2848,11 @@
doConcurrentMark();
}
-#if SCAN_ONLY_VERBOSE
+#if YOUNG_LIST_VERBOSE
+ gclog_or_tty->print_cr("\nEnd of the pause.\nYoung_list:");
_young_list->print();
-#endif // SCAN_ONLY_VERBOSE
+ g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
+#endif // YOUNG_LIST_VERBOSE
double end_time_sec = os::elapsedTime();
double pause_time_ms = (end_time_sec - start_time_sec) * MILLIUNITS;
@@ -2936,6 +2910,25 @@
}
}
+size_t G1CollectedHeap::desired_plab_sz(GCAllocPurpose purpose)
+{
+ size_t gclab_word_size;
+ switch (purpose) {
+ case GCAllocForSurvived:
+ gclab_word_size = YoungPLABSize;
+ break;
+ case GCAllocForTenured:
+ gclab_word_size = OldPLABSize;
+ break;
+ default:
+ assert(false, "unknown GCAllocPurpose");
+ gclab_word_size = OldPLABSize;
+ break;
+ }
+ return gclab_word_size;
+}
+
+
void G1CollectedHeap::set_gc_alloc_region(int purpose, HeapRegion* r) {
assert(purpose >= 0 && purpose < GCAllocPurposeCount, "invalid purpose");
// make sure we don't call set_gc_alloc_region() multiple times on
@@ -3109,6 +3102,11 @@
} else {
// the region was retained from the last collection
++_gc_alloc_region_counts[ap];
+ if (G1PrintHeapRegions) {
+ gclog_or_tty->print_cr("new alloc region %d:["PTR_FORMAT", "PTR_FORMAT"], "
+ "top "PTR_FORMAT,
+ alloc_region->hrs_index(), alloc_region->bottom(), alloc_region->end(), alloc_region->top());
+ }
}
if (alloc_region != NULL) {
@@ -3665,6 +3663,8 @@
_g1_rem(g1h->g1_rem_set()),
_hash_seed(17), _queue_num(queue_num),
_term_attempts(0),
+ _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
+ _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
_age_table(false),
#if G1_DETAILED_STATS
_pushes(0), _pops(0), _steals(0),
@@ -3691,6 +3691,9 @@
_overflowed_refs = new OverflowQueue(10);
+ _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
+ _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer;
+
_start = os::elapsedTime();
}
@@ -3988,16 +3991,13 @@
OopsInHeapRegionClosure *scan_root_cl;
OopsInHeapRegionClosure *scan_perm_cl;
- OopsInHeapRegionClosure *scan_so_cl;
if (_g1h->g1_policy()->during_initial_mark_pause()) {
scan_root_cl = &scan_mark_root_cl;
scan_perm_cl = &scan_mark_perm_cl;
- scan_so_cl = &scan_mark_heap_rs_cl;
} else {
scan_root_cl = &only_scan_root_cl;
scan_perm_cl = &only_scan_perm_cl;
- scan_so_cl = &only_scan_heap_rs_cl;
}
pss.start_strong_roots();
@@ -4005,7 +4005,6 @@
SharedHeap::SO_AllClasses,
scan_root_cl,
&push_heap_rs_cl,
- scan_so_cl,
scan_perm_cl,
i);
pss.end_strong_roots();
@@ -4067,7 +4066,6 @@
SharedHeap::ScanningOption so,
OopClosure* scan_non_heap_roots,
OopsInHeapRegionClosure* scan_rs,
- OopsInHeapRegionClosure* scan_so,
OopsInGenClosure* scan_perm,
int worker_i) {
// First scan the strong roots, including the perm gen.
@@ -4087,6 +4085,7 @@
&buf_scan_non_heap_roots,
&eager_scan_code_roots,
&buf_scan_perm);
+
// Finish up any enqueued closure apps.
buf_scan_non_heap_roots.done();
buf_scan_perm.done();
@@ -4109,9 +4108,6 @@
// XXX What should this be doing in the parallel case?
g1_policy()->record_collection_pause_end_CH_strong_roots();
- if (scan_so != NULL) {
- scan_scan_only_set(scan_so, worker_i);
- }
// Now scan the complement of the collection set.
if (scan_rs != NULL) {
g1_rem_set()->oops_into_collection_set_do(scan_rs, worker_i);
@@ -4125,54 +4121,6 @@
}
void
-G1CollectedHeap::scan_scan_only_region(HeapRegion* r,
- OopsInHeapRegionClosure* oc,
- int worker_i) {
- HeapWord* startAddr = r->bottom();
- HeapWord* endAddr = r->used_region().end();
-
- oc->set_region(r);
-
- HeapWord* p = r->bottom();
- HeapWord* t = r->top();
- guarantee( p == r->next_top_at_mark_start(), "invariant" );
- while (p < t) {
- oop obj = oop(p);
- p += obj->oop_iterate(oc);
- }
-}
-
-void
-G1CollectedHeap::scan_scan_only_set(OopsInHeapRegionClosure* oc,
- int worker_i) {
- double start = os::elapsedTime();
-
- BufferingOopsInHeapRegionClosure boc(oc);
-
- FilterInHeapRegionAndIntoCSClosure scan_only(this, &boc);
- FilterAndMarkInHeapRegionAndIntoCSClosure scan_and_mark(this, &boc, concurrent_mark());
-
- OopsInHeapRegionClosure *foc;
- if (g1_policy()->during_initial_mark_pause())
- foc = &scan_and_mark;
- else
- foc = &scan_only;
-
- HeapRegion* hr;
- int n = 0;
- while ((hr = _young_list->par_get_next_scan_only_region()) != NULL) {
- scan_scan_only_region(hr, foc, worker_i);
- ++n;
- }
- boc.done();
-
- double closure_app_s = boc.closure_app_seconds();
- g1_policy()->record_obj_copy_time(worker_i, closure_app_s * 1000.0);
- double ms = (os::elapsedTime() - start - closure_app_s)*1000.0;
- g1_policy()->record_scan_only_time(worker_i, ms, n);
-}
-
-void
G1CollectedHeap::g1_process_weak_roots(OopClosure* root_closure,
OopClosure* non_root_closure) {
CodeBlobToOopClosure roots_in_blobs(root_closure, /*do_marking=*/ false);
@@ -4370,17 +4318,14 @@
class G1ParCleanupCTTask : public AbstractGangTask {
CardTableModRefBS* _ct_bs;
G1CollectedHeap* _g1h;
- HeapRegion* volatile _so_head;
HeapRegion* volatile _su_head;
public:
G1ParCleanupCTTask(CardTableModRefBS* ct_bs,
G1CollectedHeap* g1h,
- HeapRegion* scan_only_list,
HeapRegion* survivor_list) :
AbstractGangTask("G1 Par Cleanup CT Task"),
_ct_bs(ct_bs),
_g1h(g1h),
- _so_head(scan_only_list),
_su_head(survivor_list)
{ }
@@ -4389,14 +4334,13 @@
while (r = _g1h->pop_dirty_cards_region()) {
clear_cards(r);
}
- // Redirty the cards of the scan-only and survivor regions.
- dirty_list(&this->_so_head);
+ // Redirty the cards of the survivor regions.
dirty_list(&this->_su_head);
}
void clear_cards(HeapRegion* r) {
- // Cards for Survivor and Scan-Only regions will be dirtied later.
- if (!r->is_scan_only() && !r->is_survivor()) {
+ // Cards for Survivor regions will be dirtied later.
+ if (!r->is_survivor()) {
_ct_bs->clear(MemRegion(r->bottom(), r->end()));
}
}
@@ -4429,7 +4373,7 @@
virtual bool doHeapRegion(HeapRegion* r)
{
MemRegion mr(r->bottom(), r->end());
- if (r->is_scan_only() || r->is_survivor()) {
+ if (r->is_survivor()) {
_ct_bs->verify_dirty_region(mr);
} else {
_ct_bs->verify_clean_region(mr);
@@ -4445,8 +4389,8 @@
// Iterate over the dirty cards region list.
G1ParCleanupCTTask cleanup_task(ct_bs, this,
- _young_list->first_scan_only_region(),
_young_list->first_survivor_region());
+
if (ParallelGCThreads > 0) {
set_par_threads(workers()->total_workers());
workers()->run_task(&cleanup_task);
@@ -4462,12 +4406,12 @@
}
r->set_next_dirty_cards_region(NULL);
}
- // now, redirty the cards of the scan-only and survivor regions
+ // now, redirty the cards of the survivor regions
// (it seemed faster to do it this way, instead of iterating over
// all regions and then clearing / dirtying as appropriate)
- dirtyCardsForYoungRegions(ct_bs, _young_list->first_scan_only_region());
dirtyCardsForYoungRegions(ct_bs, _young_list->first_survivor_region());
}
+
double elapsed = os::elapsedTime() - start;
g1_policy()->record_clear_ct_time( elapsed * 1000.0);
#ifndef PRODUCT
@@ -4488,6 +4432,11 @@
double young_time_ms = 0.0;
double non_young_time_ms = 0.0;
+ // Since the collection set is a superset of the the young list,
+ // all we need to do to clear the young list is clear its
+ // head and length, and unlink any young regions in the code below
+ _young_list->clear();
+
G1CollectorPolicy* policy = g1_policy();
double start_sec = os::elapsedTime();
@@ -4531,6 +4480,12 @@
guarantee( (size_t)index < policy->young_cset_length(), "invariant" );
size_t words_survived = _surviving_young_words[index];
cur->record_surv_words_in_group(words_survived);
+
+ // At this point the we have 'popped' cur from the collection set
+ // (linked via next_in_collection_set()) but it is still in the
+ // young list (linked via next_young_region()). Clear the
+ // _next_young_region field.
+ cur->set_next_young_region(NULL);
} else {
int index = cur->young_index_in_cset();
guarantee( index == -1, "invariant" );
@@ -4546,7 +4501,6 @@
"Should not have empty regions in a CS.");
free_region(cur);
} else {
- guarantee( !cur->is_scan_only(), "should not be scan only" );
cur->uninstall_surv_rate_group();
if (cur->is_young())
cur->set_young_index_in_cset(-1);
@@ -4570,6 +4524,27 @@
policy->record_non_young_free_cset_time_ms(non_young_time_ms);
}
+// This routine is similar to the above but does not record
+// any policy statistics or update free lists; we are abandoning
+// the current incremental collection set in preparation of a
+// full collection. After the full GC we will start to build up
+// the incremental collection set again.
+// This is only called when we're doing a full collection
+// and is immediately followed by the tearing down of the young list.
+
+void G1CollectedHeap::abandon_collection_set(HeapRegion* cs_head) {
+ HeapRegion* cur = cs_head;
+
+ while (cur != NULL) {
+ HeapRegion* next = cur->next_in_collection_set();
+ assert(cur->in_collection_set(), "bad CS");
+ cur->set_next_in_collection_set(NULL);
+ cur->set_in_collection_set(false);
+ cur->set_young_index_in_cset(-1);
+ cur = next;
+ }
+}
+
HeapRegion*
G1CollectedHeap::alloc_region_from_unclean_list_locked(bool zero_filled) {
assert(ZF_mon->owned_by_self(), "Precondition");
@@ -4936,12 +4911,10 @@
bool success() { return _success; }
};
-bool G1CollectedHeap::check_young_list_empty(bool ignore_scan_only_list,
- bool check_sample) {
- bool ret = true;
-
- ret = _young_list->check_list_empty(ignore_scan_only_list, check_sample);
- if (!ignore_scan_only_list) {
+bool G1CollectedHeap::check_young_list_empty(bool check_heap, bool check_sample) {
+ bool ret = _young_list->check_list_empty(check_sample);
+
+ if (check_heap) {
NoYoungRegionsClosure closure;
heap_region_iterate(&closure);
ret = ret && closure.success();
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -81,33 +81,29 @@
HeapRegion* _head;
- HeapRegion* _scan_only_head;
- HeapRegion* _scan_only_tail;
+ HeapRegion* _survivor_head;
+ HeapRegion* _survivor_tail;
+
+ HeapRegion* _curr;
+
size_t _length;
- size_t _scan_only_length;
+ size_t _survivor_length;
size_t _last_sampled_rs_lengths;
size_t _sampled_rs_lengths;
- HeapRegion* _curr;
- HeapRegion* _curr_scan_only;
- HeapRegion* _survivor_head;
- HeapRegion* _survivor_tail;
- size_t _survivor_length;
-
- void empty_list(HeapRegion* list);
+ void empty_list(HeapRegion* list);
public:
YoungList(G1CollectedHeap* g1h);
- void push_region(HeapRegion* hr);
- void add_survivor_region(HeapRegion* hr);
- HeapRegion* pop_region();
- void empty_list();
- bool is_empty() { return _length == 0; }
- size_t length() { return _length; }
- size_t scan_only_length() { return _scan_only_length; }
- size_t survivor_length() { return _survivor_length; }
+ void push_region(HeapRegion* hr);
+ void add_survivor_region(HeapRegion* hr);
+
+ void empty_list();
+ bool is_empty() { return _length == 0; }
+ size_t length() { return _length; }
+ size_t survivor_length() { return _survivor_length; }
void rs_length_sampling_init();
bool rs_length_sampling_more();
@@ -120,22 +116,21 @@
// for development purposes
void reset_auxilary_lists();
+ void clear() { _head = NULL; _length = 0; }
+
+ void clear_survivors() {
+ _survivor_head = NULL;
+ _survivor_tail = NULL;
+ _survivor_length = 0;
+ }
+
HeapRegion* first_region() { return _head; }
- HeapRegion* first_scan_only_region() { return _scan_only_head; }
HeapRegion* first_survivor_region() { return _survivor_head; }
HeapRegion* last_survivor_region() { return _survivor_tail; }
- HeapRegion* par_get_next_scan_only_region() {
- MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
- HeapRegion* ret = _curr_scan_only;
- if (ret != NULL)
- _curr_scan_only = ret->get_next_young_region();
- return ret;
- }
// debugging
bool check_list_well_formed();
- bool check_list_empty(bool ignore_scan_only_list,
- bool check_sample = true);
+ bool check_list_empty(bool check_sample = true);
void print();
};
@@ -232,6 +227,9 @@
// current collection.
HeapRegion* _gc_alloc_region_list;
+ // Determines PLAB size for a particular allocation purpose.
+ static size_t desired_plab_sz(GCAllocPurpose purpose);
+
// When called by par thread, require par_alloc_during_gc_lock() to be held.
void push_gc_alloc_region(HeapRegion* hr);
@@ -402,8 +400,7 @@
assert(_in_cset_fast_test_base != NULL, "sanity");
assert(r->in_collection_set(), "invariant");
int index = r->hrs_index();
- assert(0 <= (size_t) index && (size_t) index < _in_cset_fast_test_length,
- "invariant");
+ assert(0 <= index && (size_t) index < _in_cset_fast_test_length, "invariant");
assert(!_in_cset_fast_test_base[index], "invariant");
_in_cset_fast_test_base[index] = true;
}
@@ -428,6 +425,12 @@
}
}
+ void clear_cset_fast_test() {
+ assert(_in_cset_fast_test_base != NULL, "sanity");
+ memset(_in_cset_fast_test_base, false,
+ _in_cset_fast_test_length * sizeof(bool));
+ }
+
protected:
// Shrink the garbage-first heap by at most the given size (in bytes!).
@@ -473,6 +476,10 @@
// regions.
void free_collection_set(HeapRegion* cs_head);
+ // Abandon the current collection set without recording policy
+ // statistics or updating free lists.
+ void abandon_collection_set(HeapRegion* cs_head);
+
// Applies "scan_non_heap_roots" to roots outside the heap,
// "scan_rs" to roots inside the heap (having done "set_region" to
// indicate the region in which the root resides), and does "scan_perm"
@@ -485,16 +492,9 @@
SharedHeap::ScanningOption so,
OopClosure* scan_non_heap_roots,
OopsInHeapRegionClosure* scan_rs,
- OopsInHeapRegionClosure* scan_so,
OopsInGenClosure* scan_perm,
int worker_i);
- void scan_scan_only_set(OopsInHeapRegionClosure* oc,
- int worker_i);
- void scan_scan_only_region(HeapRegion* hr,
- OopsInHeapRegionClosure* oc,
- int worker_i);
-
// Apply "blk" to all the weak roots of the system. These include
// JNI weak roots, the code cache, system dictionary, symbol table,
// string table, and referents of reachable weak refs.
@@ -1133,36 +1133,14 @@
void set_region_short_lived_locked(HeapRegion* hr);
// add appropriate methods for any other surv rate groups
- void young_list_rs_length_sampling_init() {
- _young_list->rs_length_sampling_init();
- }
- bool young_list_rs_length_sampling_more() {
- return _young_list->rs_length_sampling_more();
- }
- void young_list_rs_length_sampling_next() {
- _young_list->rs_length_sampling_next();
- }
- size_t young_list_sampled_rs_lengths() {
- return _young_list->sampled_rs_lengths();
- }
-
- size_t young_list_length() { return _young_list->length(); }
- size_t young_list_scan_only_length() {
- return _young_list->scan_only_length(); }
-
- HeapRegion* pop_region_from_young_list() {
- return _young_list->pop_region();
- }
-
- HeapRegion* young_list_first_region() {
- return _young_list->first_region();
- }
+ YoungList* young_list() { return _young_list; }
// debugging
bool check_young_list_well_formed() {
return _young_list->check_list_well_formed();
}
- bool check_young_list_empty(bool ignore_scan_only_list,
+
+ bool check_young_list_empty(bool check_heap,
bool check_sample = true);
// *** Stuff related to concurrent marking. It's not clear to me that so
@@ -1367,12 +1345,18 @@
return BitsPerWord << shifter();
}
- static size_t gclab_word_size() {
- return G1ParallelGCAllocBufferSize / HeapWordSize;
+ size_t gclab_word_size() const {
+ return _gclab_word_size;
}
- static size_t bitmap_size_in_bits() {
- size_t bits_in_bitmap = gclab_word_size() >> shifter();
+ // Calculates actual GCLab size in words
+ size_t gclab_real_word_size() const {
+ return bitmap_size_in_bits(pointer_delta(_real_end_word, _start_word))
+ / BitsPerWord;
+ }
+
+ static size_t bitmap_size_in_bits(size_t gclab_word_size) {
+ size_t bits_in_bitmap = gclab_word_size >> shifter();
// We are going to ensure that the beginning of a word in this
// bitmap also corresponds to the beginning of a word in the
// global marking bitmap. To handle the case where a GCLab
@@ -1382,13 +1366,13 @@
return bits_in_bitmap + BitsPerWord - 1;
}
public:
- GCLabBitMap(HeapWord* heap_start)
- : BitMap(bitmap_size_in_bits()),
+ GCLabBitMap(HeapWord* heap_start, size_t gclab_word_size)
+ : BitMap(bitmap_size_in_bits(gclab_word_size)),
_cm(G1CollectedHeap::heap()->concurrent_mark()),
_shifter(shifter()),
_bitmap_word_covers_words(bitmap_word_covers_words()),
_heap_start(heap_start),
- _gclab_word_size(gclab_word_size()),
+ _gclab_word_size(gclab_word_size),
_real_start_word(NULL),
_real_end_word(NULL),
_start_word(NULL)
@@ -1483,7 +1467,7 @@
mark_bitmap->mostly_disjoint_range_union(this,
0, // always start from the start of the bitmap
_start_word,
- size_in_words());
+ gclab_real_word_size());
_cm->grayRegionIfNecessary(MemRegion(_real_start_word, _real_end_word));
#ifndef PRODUCT
@@ -1495,9 +1479,10 @@
}
}
- static size_t bitmap_size_in_words() {
- return (bitmap_size_in_bits() + BitsPerWord - 1) / BitsPerWord;
+ size_t bitmap_size_in_words() const {
+ return (bitmap_size_in_bits(gclab_word_size()) + BitsPerWord - 1) / BitsPerWord;
}
+
};
class G1ParGCAllocBuffer: public ParGCAllocBuffer {
@@ -1507,10 +1492,10 @@
GCLabBitMap _bitmap;
public:
- G1ParGCAllocBuffer() :
- ParGCAllocBuffer(G1ParallelGCAllocBufferSize / HeapWordSize),
+ G1ParGCAllocBuffer(size_t gclab_word_size) :
+ ParGCAllocBuffer(gclab_word_size),
_during_marking(G1CollectedHeap::heap()->mark_in_progress()),
- _bitmap(G1CollectedHeap::heap()->reserved_region().start()),
+ _bitmap(G1CollectedHeap::heap()->reserved_region().start(), gclab_word_size),
_retired(false)
{ }
@@ -1549,8 +1534,10 @@
typedef GrowableArray<StarTask> OverflowQueue;
OverflowQueue* _overflowed_refs;
- G1ParGCAllocBuffer _alloc_buffers[GCAllocPurposeCount];
- ageTable _age_table;
+ G1ParGCAllocBuffer _surviving_alloc_buffer;
+ G1ParGCAllocBuffer _tenured_alloc_buffer;
+ G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
+ ageTable _age_table;
size_t _alloc_buffer_waste;
size_t _undo_waste;
@@ -1619,7 +1606,7 @@
ageTable* age_table() { return &_age_table; }
G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
- return &_alloc_buffers[purpose];
+ return _alloc_buffers[purpose];
}
size_t alloc_buffer_waste() { return _alloc_buffer_waste; }
@@ -1684,15 +1671,15 @@
HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) {
HeapWord* obj = NULL;
- if (word_sz * 100 <
- (size_t)(G1ParallelGCAllocBufferSize / HeapWordSize) *
- ParallelGCBufferWastePct) {
+ size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
+ if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
+ assert(gclab_word_size == alloc_buf->word_sz(),
+ "dynamic resizing is not supported");
add_to_alloc_buffer_waste(alloc_buf->words_remaining());
alloc_buf->retire(false, false);
- HeapWord* buf =
- _g1h->par_allocate_during_gc(purpose, G1ParallelGCAllocBufferSize / HeapWordSize);
+ HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size);
if (buf == NULL) return NULL; // Let caller handle allocation failure.
// Otherwise.
alloc_buf->set_buf(buf);
@@ -1786,9 +1773,9 @@
void retire_alloc_buffers() {
for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
- size_t waste = _alloc_buffers[ap].words_remaining();
+ size_t waste = _alloc_buffers[ap]->words_remaining();
add_to_alloc_buffer_waste(waste);
- _alloc_buffers[ap].retire(true, false);
+ _alloc_buffers[ap]->retire(true, false);
}
}
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -42,10 +42,6 @@
0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
};
-static double cost_per_scan_only_region_ms_defaults[] = {
- 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
-};
-
// all the same
static double fully_young_cards_per_entry_ratio_defaults[] = {
1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
@@ -125,7 +121,6 @@
_pending_card_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
_rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
_cost_per_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
- _cost_per_scan_only_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
_fully_young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
_partially_young_cards_per_entry_ratio_seq(
new TruncatedSeq(TruncatedSeqLength)),
@@ -133,7 +128,6 @@
_partially_young_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
_cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
_cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
- _cost_per_scan_only_region_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
_constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
_young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
_non_young_other_cost_per_region_ms_seq(
@@ -186,6 +180,22 @@
_prev_collection_pause_used_at_end_bytes(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
#endif // _MSC_VER
@@ -209,13 +219,20 @@
HeapRegion::setup_heap_region_size(Arguments::min_heap_size());
HeapRegionRemSet::setup_remset_size();
+ // Verify PLAB sizes
+ const uint region_size = HeapRegion::GrainWords;
+ if (YoungPLABSize > region_size || OldPLABSize > region_size) {
+ char buffer[128];
+ jio_snprintf(buffer, sizeof(buffer), "%sPLABSize should be at most %u",
+ OldPLABSize > region_size ? "Old" : "Young", region_size);
+ vm_exit_during_initialization(buffer);
+ }
+
_recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
_prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
_par_last_ext_root_scan_times_ms = new double[_parallel_gc_threads];
_par_last_mark_stack_scan_times_ms = new double[_parallel_gc_threads];
- _par_last_scan_only_times_ms = new double[_parallel_gc_threads];
- _par_last_scan_only_regions_scanned = new double[_parallel_gc_threads];
_par_last_update_rs_start_times_ms = new double[_parallel_gc_threads];
_par_last_update_rs_times_ms = new double[_parallel_gc_threads];
@@ -245,8 +262,6 @@
_pending_card_diff_seq->add(0.0);
_rs_length_diff_seq->add(rs_length_diff_defaults[index]);
_cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]);
- _cost_per_scan_only_region_ms_seq->add(
- cost_per_scan_only_region_ms_defaults[index]);
_fully_young_cards_per_entry_ratio_seq->add(
fully_young_cards_per_entry_ratio_defaults[index]);
_cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]);
@@ -274,7 +289,7 @@
// if G1FixedSurvivorSpaceSize is 0 which means the size is not
// fixed, then _max_survivor_regions will be calculated at
- // calculate_young_list_target_config during initialization
+ // calculate_young_list_target_length during initialization
_max_survivor_regions = G1FixedSurvivorSpaceSize / HeapRegion::GrainBytes;
assert(GCTimeRatio > 0,
@@ -348,15 +363,18 @@
set_adaptive_young_list_length(false);
_young_list_fixed_length = initial_region_num;
}
- _free_regions_at_end_of_collection = _g1->free_regions();
- _scan_only_regions_at_end_of_collection = 0;
- calculate_young_list_min_length();
- guarantee( _young_list_min_length == 0, "invariant, not enough info" );
- calculate_young_list_target_config();
- } else {
+ _free_regions_at_end_of_collection = _g1->free_regions();
+ calculate_young_list_min_length();
+ guarantee( _young_list_min_length == 0, "invariant, not enough info" );
+ calculate_young_list_target_length();
+ } else {
_young_list_fixed_length = 0;
_in_young_gc_mode = false;
}
+
+ // We may immediately start allocating regions and placing them on the
+ // collection set list. Initialize the per-collection set info
+ start_incremental_cset_building();
}
// Create the jstat counters for the policy.
@@ -376,112 +394,29 @@
double when_ms = _mmu_tracker->when_max_gc_sec(now_sec) * 1000.0;
double alloc_rate_ms = predict_alloc_rate_ms();
int min_regions = (int) ceil(alloc_rate_ms * when_ms);
- int current_region_num = (int) _g1->young_list_length();
+ int current_region_num = (int) _g1->young_list()->length();
_young_list_min_length = min_regions + current_region_num;
}
}
-void G1CollectorPolicy::calculate_young_list_target_config() {
+void G1CollectorPolicy::calculate_young_list_target_length() {
if (adaptive_young_list_length()) {
size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
- calculate_young_list_target_config(rs_lengths);
+ calculate_young_list_target_length(rs_lengths);
} else {
if (full_young_gcs())
_young_list_target_length = _young_list_fixed_length;
else
_young_list_target_length = _young_list_fixed_length / 2;
+
_young_list_target_length = MAX2(_young_list_target_length, (size_t)1);
- size_t so_length = calculate_optimal_so_length(_young_list_target_length);
- guarantee( so_length < _young_list_target_length, "invariant" );
- _young_list_so_prefix_length = so_length;
}
calculate_survivors_policy();
}
-// This method calculate the optimal scan-only set for a fixed young
-// gen size. I couldn't work out how to reuse the more elaborate one,
-// i.e. calculate_young_list_target_config(rs_length), as the loops are
-// fundamentally different (the other one finds a config for different
-// S-O lengths, whereas here we need to do the opposite).
-size_t G1CollectorPolicy::calculate_optimal_so_length(
- size_t young_list_length) {
- if (!G1UseScanOnlyPrefix)
- return 0;
-
- if (_all_pause_times_ms->num() < 3) {
- // we won't use a scan-only set at the beginning to allow the rest
- // of the predictors to warm up
- return 0;
- }
-
- if (_cost_per_scan_only_region_ms_seq->num() < 3) {
- // then, we'll only set the S-O set to 1 for a little bit of time,
- // to get enough information on the scanning cost
- return 1;
- }
-
- size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
- size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
- size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
- size_t scanned_cards;
- if (full_young_gcs())
- scanned_cards = predict_young_card_num(adj_rs_lengths);
- else
- scanned_cards = predict_non_young_card_num(adj_rs_lengths);
- double base_time_ms = predict_base_elapsed_time_ms(pending_cards,
- scanned_cards);
-
- size_t so_length = 0;
- double max_gc_eff = 0.0;
- for (size_t i = 0; i < young_list_length; ++i) {
- double gc_eff = 0.0;
- double pause_time_ms = 0.0;
- predict_gc_eff(young_list_length, i, base_time_ms,
- &gc_eff, &pause_time_ms);
- if (gc_eff > max_gc_eff) {
- max_gc_eff = gc_eff;
- so_length = i;
- }
- }
-
- // set it to 95% of the optimal to make sure we sample the "area"
- // around the optimal length to get up-to-date survival rate data
- return so_length * 950 / 1000;
-}
-
-// This is a really cool piece of code! It finds the best
-// target configuration (young length / scan-only prefix length) so
-// that GC efficiency is maximized and that we also meet a pause
-// time. It's a triple nested loop. These loops are explained below
-// from the inside-out :-)
-//
-// (a) The innermost loop will try to find the optimal young length
-// for a fixed S-O length. It uses a binary search to speed up the
-// process. We assume that, for a fixed S-O length, as we add more
-// young regions to the CSet, the GC efficiency will only go up (I'll
-// skip the proof). So, using a binary search to optimize this process
-// makes perfect sense.
-//
-// (b) The middle loop will fix the S-O length before calling the
-// innermost one. It will vary it between two parameters, increasing
-// it by a given increment.
-//
-// (c) The outermost loop will call the middle loop three times.
-// (1) The first time it will explore all possible S-O length values
-// from 0 to as large as it can get, using a coarse increment (to
-// quickly "home in" to where the optimal seems to be).
-// (2) The second time it will explore the values around the optimal
-// that was found by the first iteration using a fine increment.
-// (3) Once the optimal config has been determined by the second
-// iteration, we'll redo the calculation, but setting the S-O length
-// to 95% of the optimal to make sure we sample the "area"
-// around the optimal length to get up-to-date survival rate data
-//
-// Termination conditions for the iterations are several: the pause
-// time is over the limit, we do not have enough to-space, etc.
-
-void G1CollectorPolicy::calculate_young_list_target_config(size_t rs_lengths) {
+void G1CollectorPolicy::calculate_young_list_target_length(size_t rs_lengths) {
guarantee( adaptive_young_list_length(), "pre-condition" );
+ guarantee( !_in_marking_window || !_last_full_young_gc, "invariant" );
double start_time_sec = os::elapsedTime();
size_t min_reserve_perc = MAX2((size_t)2, (size_t)G1ReservePercent);
@@ -495,285 +430,80 @@
double survivor_regions_evac_time =
predict_survivor_regions_evac_time();
- size_t min_so_length = 0;
- size_t max_so_length = 0;
-
- if (G1UseScanOnlyPrefix) {
- if (_all_pause_times_ms->num() < 3) {
- // we won't use a scan-only set at the beginning to allow the rest
- // of the predictors to warm up
- min_so_length = 0;
- max_so_length = 0;
- } else if (_cost_per_scan_only_region_ms_seq->num() < 3) {
- // then, we'll only set the S-O set to 1 for a little bit of time,
- // to get enough information on the scanning cost
- min_so_length = 1;
- max_so_length = 1;
- } else if (_in_marking_window || _last_full_young_gc) {
- // no S-O prefix during a marking phase either, as at the end
- // of the marking phase we'll have to use a very small young
- // length target to fill up the rest of the CSet with
- // non-young regions and, if we have lots of scan-only regions
- // left-over, we will not be able to add any more non-young
- // regions.
- min_so_length = 0;
- max_so_length = 0;
- } else {
- // this is the common case; we'll never reach the maximum, we
- // one of the end conditions will fire well before that
- // (hopefully!)
- min_so_length = 0;
- max_so_length = _free_regions_at_end_of_collection - 1;
- }
- } else {
- // no S-O prefix, as the switch is not set, but we still need to
- // do one iteration to calculate the best young target that
- // meets the pause time; this way we reuse the same code instead
- // of replicating it
- min_so_length = 0;
- max_so_length = 0;
- }
-
double target_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
- size_t scanned_cards;
- if (full_young_gcs())
- scanned_cards = predict_young_card_num(adj_rs_lengths);
- else
- scanned_cards = predict_non_young_card_num(adj_rs_lengths);
- // calculate this once, so that we don't have to recalculate it in
- // the innermost loop
+ size_t scanned_cards = predict_young_card_num(adj_rs_lengths);
double base_time_ms = predict_base_elapsed_time_ms(pending_cards, scanned_cards)
+ survivor_regions_evac_time;
+
// the result
size_t final_young_length = 0;
- size_t final_so_length = 0;
- double final_gc_eff = 0.0;
- // we'll also keep track of how many times we go into the inner loop
- // this is for profiling reasons
- size_t calculations = 0;
-
- // this determines which of the three iterations the outer loop is in
- typedef enum {
- pass_type_coarse,
- pass_type_fine,
- pass_type_final
- } pass_type_t;
-
- // range of the outer loop's iteration
- size_t from_so_length = min_so_length;
- size_t to_so_length = max_so_length;
- guarantee( from_so_length <= to_so_length, "invariant" );
-
- // this will keep the S-O length that's found by the second
- // iteration of the outer loop; we'll keep it just in case the third
- // iteration fails to find something
- size_t fine_so_length = 0;
-
- // the increment step for the coarse (first) iteration
- size_t so_coarse_increments = 5;
-
- // the common case, we'll start with the coarse iteration
- pass_type_t pass = pass_type_coarse;
- size_t so_length_incr = so_coarse_increments;
-
- if (from_so_length == to_so_length) {
- // not point in doing the coarse iteration, we'll go directly into
- // the fine one (we essentially trying to find the optimal young
- // length for a fixed S-O length).
- so_length_incr = 1;
- pass = pass_type_final;
- } else if (to_so_length - from_so_length < 3 * so_coarse_increments) {
- // again, the range is too short so no point in foind the coarse
- // iteration either
- so_length_incr = 1;
- pass = pass_type_fine;
- }
-
- bool done = false;
- // this is the outermost loop
- while (!done) {
-#ifdef TRACE_CALC_YOUNG_CONFIG
- // leave this in for debugging, just in case
- gclog_or_tty->print_cr("searching between " SIZE_FORMAT " and " SIZE_FORMAT
- ", incr " SIZE_FORMAT ", pass %s",
- from_so_length, to_so_length, so_length_incr,
- (pass == pass_type_coarse) ? "coarse" :
- (pass == pass_type_fine) ? "fine" : "final");
-#endif // TRACE_CALC_YOUNG_CONFIG
-
- size_t so_length = from_so_length;
- size_t init_free_regions =
- MAX2((size_t)0,
- _free_regions_at_end_of_collection +
- _scan_only_regions_at_end_of_collection - reserve_regions);
-
- // this determines whether a configuration was found
- bool gc_eff_set = false;
- // this is the middle loop
- while (so_length <= to_so_length) {
- // base time, which excludes region-related time; again we
- // calculate it once to avoid recalculating it in the
- // innermost loop
- double base_time_with_so_ms =
- base_time_ms + predict_scan_only_time_ms(so_length);
- // it's already over the pause target, go around
- if (base_time_with_so_ms > target_pause_time_ms)
- break;
-
- size_t starting_young_length = so_length+1;
-
- // we make sure that the short young length that makes sense
- // (one more than the S-O length) is feasible
- size_t min_young_length = starting_young_length;
- double min_gc_eff;
- bool min_ok;
- ++calculations;
- min_ok = predict_gc_eff(min_young_length, so_length,
- base_time_with_so_ms,
- init_free_regions, target_pause_time_ms,
- &min_gc_eff);
-
- if (min_ok) {
- // the shortest young length is indeed feasible; we'll know
- // set up the max young length and we'll do a binary search
- // between min_young_length and max_young_length
- size_t max_young_length = _free_regions_at_end_of_collection - 1;
- double max_gc_eff = 0.0;
- bool max_ok = false;
-
- // the innermost loop! (finally!)
- while (max_young_length > min_young_length) {
- // we'll make sure that min_young_length is always at a
- // feasible config
- guarantee( min_ok, "invariant" );
-
- ++calculations;
- max_ok = predict_gc_eff(max_young_length, so_length,
- base_time_with_so_ms,
- init_free_regions, target_pause_time_ms,
- &max_gc_eff);
+
+ size_t init_free_regions =
+ MAX2((size_t)0, _free_regions_at_end_of_collection - reserve_regions);
+
+ // if we're still under the pause target...
+ if (base_time_ms <= target_pause_time_ms) {
+ // We make sure that the shortest young length that makes sense
+ // fits within the target pause time.
+ size_t min_young_length = 1;
+
+ if (predict_will_fit(min_young_length, base_time_ms,
+ init_free_regions, target_pause_time_ms)) {
+ // The shortest young length will fit within the target pause time;
+ // we'll now check whether the absolute maximum number of young
+ // regions will fit in the target pause time. If not, we'll do
+ // a binary search between min_young_length and max_young_length
+ size_t abs_max_young_length = _free_regions_at_end_of_collection - 1;
+ size_t max_young_length = abs_max_young_length;
+
+ if (max_young_length > min_young_length) {
+ // Let's check if the initial max young length will fit within the
+ // target pause. If so then there is no need to search for a maximal
+ // young length - we'll return the initial maximum
+
+ if (predict_will_fit(max_young_length, base_time_ms,
+ init_free_regions, target_pause_time_ms)) {
+ // The maximum young length will satisfy the target pause time.
+ // We are done so set min young length to this maximum length.
+ // The code after the loop will then set final_young_length using
+ // the value cached in the minimum length.
+ min_young_length = max_young_length;
+ } else {
+ // The maximum possible number of young regions will not fit within
+ // the target pause time so let's search....
size_t diff = (max_young_length - min_young_length) / 2;
- if (max_ok) {
- min_young_length = max_young_length;
- min_gc_eff = max_gc_eff;
- min_ok = true;
+ max_young_length = min_young_length + diff;
+
+ while (max_young_length > min_young_length) {
+ if (predict_will_fit(max_young_length, base_time_ms,
+ init_free_regions, target_pause_time_ms)) {
+
+ // The current max young length will fit within the target
+ // pause time. Note we do not exit the loop here. By setting
+ // min = max, and then increasing the max below means that
+ // we will continue searching for an upper bound in the
+ // range [max..max+diff]
+ min_young_length = max_young_length;
+ }
+ diff = (max_young_length - min_young_length) / 2;
+ max_young_length = min_young_length + diff;
}
- max_young_length = min_young_length + diff;
+ // the above loop found a maximal young length that will fit
+ // within the target pause time.
}
-
- // the innermost loop found a config
- guarantee( min_ok, "invariant" );
- if (min_gc_eff > final_gc_eff) {
- // it's the best config so far, so we'll keep it
- final_gc_eff = min_gc_eff;
- final_young_length = min_young_length;
- final_so_length = so_length;
- gc_eff_set = true;
- }
+ assert(min_young_length <= abs_max_young_length, "just checking");
}
-
- // incremental the fixed S-O length and go around
- so_length += so_length_incr;
+ final_young_length = min_young_length;
}
-
- // this is the end of the outermost loop and we need to decide
- // what to do during the next iteration
- if (pass == pass_type_coarse) {
- // we just did the coarse pass (first iteration)
-
- if (!gc_eff_set)
- // we didn't find a feasible config so we'll just bail out; of
- // course, it might be the case that we missed it; but I'd say
- // it's a bit unlikely
- done = true;
- else {
- // We did find a feasible config with optimal GC eff during
- // the first pass. So the second pass we'll only consider the
- // S-O lengths around that config with a fine increment.
-
- guarantee( so_length_incr == so_coarse_increments, "invariant" );
- guarantee( final_so_length >= min_so_length, "invariant" );
-
-#ifdef TRACE_CALC_YOUNG_CONFIG
- // leave this in for debugging, just in case
- gclog_or_tty->print_cr(" coarse pass: SO length " SIZE_FORMAT,
- final_so_length);
-#endif // TRACE_CALC_YOUNG_CONFIG
-
- from_so_length =
- (final_so_length - min_so_length > so_coarse_increments) ?
- final_so_length - so_coarse_increments + 1 : min_so_length;
- to_so_length =
- (max_so_length - final_so_length > so_coarse_increments) ?
- final_so_length + so_coarse_increments - 1 : max_so_length;
-
- pass = pass_type_fine;
- so_length_incr = 1;
- }
- } else if (pass == pass_type_fine) {
- // we just finished the second pass
-
- if (!gc_eff_set) {
- // we didn't find a feasible config (yes, it's possible;
- // notice that, sometimes, we go directly into the fine
- // iteration and skip the coarse one) so we bail out
- done = true;
- } else {
- // We did find a feasible config with optimal GC eff
- guarantee( so_length_incr == 1, "invariant" );
-
- if (final_so_length == 0) {
- // The config is of an empty S-O set, so we'll just bail out
- done = true;
- } else {
- // we'll go around once more, setting the S-O length to 95%
- // of the optimal
- size_t new_so_length = 950 * final_so_length / 1000;
-
-#ifdef TRACE_CALC_YOUNG_CONFIG
- // leave this in for debugging, just in case
- gclog_or_tty->print_cr(" fine pass: SO length " SIZE_FORMAT
- ", setting it to " SIZE_FORMAT,
- final_so_length, new_so_length);
-#endif // TRACE_CALC_YOUNG_CONFIG
-
- from_so_length = new_so_length;
- to_so_length = new_so_length;
- fine_so_length = final_so_length;
-
- pass = pass_type_final;
- }
- }
- } else if (pass == pass_type_final) {
- // we just finished the final (third) pass
-
- if (!gc_eff_set)
- // we didn't find a feasible config, so we'll just use the one
- // we found during the second pass, which we saved
- final_so_length = fine_so_length;
-
- // and we're done!
- done = true;
- } else {
- guarantee( false, "should never reach here" );
- }
-
- // we now go around the outermost loop
}
+ // and we're done!
// we should have at least one region in the target young length
_young_list_target_length =
MAX2((size_t) 1, final_young_length + _recorded_survivor_regions);
- if (final_so_length >= final_young_length)
- // and we need to ensure that the S-O length is not greater than
- // the target young length (this is being a bit careful)
- final_so_length = 0;
- _young_list_so_prefix_length = final_so_length;
- guarantee( !_in_marking_window || !_last_full_young_gc ||
- _young_list_so_prefix_length == 0, "invariant" );
// let's keep an eye of how long we spend on this calculation
// right now, I assume that we'll print it when we need it; we
@@ -781,142 +511,91 @@
double end_time_sec = os::elapsedTime();
double elapsed_time_ms = (end_time_sec - start_time_sec) * 1000.0;
-#ifdef TRACE_CALC_YOUNG_CONFIG
+#ifdef TRACE_CALC_YOUNG_LENGTH
// leave this in for debugging, just in case
- gclog_or_tty->print_cr("target = %1.1lf ms, young = " SIZE_FORMAT
- ", SO = " SIZE_FORMAT ", "
- "elapsed %1.2lf ms, calcs: " SIZE_FORMAT " (%s%s) "
- SIZE_FORMAT SIZE_FORMAT,
+ gclog_or_tty->print_cr("target = %1.1lf ms, young = " SIZE_FORMAT ", "
+ "elapsed %1.2lf ms, (%s%s) " SIZE_FORMAT SIZE_FORMAT,
target_pause_time_ms,
- _young_list_target_length - _young_list_so_prefix_length,
- _young_list_so_prefix_length,
+ _young_list_target_length
elapsed_time_ms,
- calculations,
full_young_gcs() ? "full" : "partial",
during_initial_mark_pause() ? " i-m" : "",
_in_marking_window,
_in_marking_window_im);
-#endif // TRACE_CALC_YOUNG_CONFIG
+#endif // TRACE_CALC_YOUNG_LENGTH
if (_young_list_target_length < _young_list_min_length) {
- // bummer; this means that, if we do a pause when the optimal
- // config dictates, we'll violate the pause spacing target (the
+ // bummer; this means that, if we do a pause when the maximal
+ // length dictates, we'll violate the pause spacing target (the
// min length was calculate based on the application's current
// alloc rate);
// so, we have to bite the bullet, and allocate the minimum
// number. We'll violate our target, but we just can't meet it.
- size_t so_length = 0;
- // a note further up explains why we do not want an S-O length
- // during marking
- if (!_in_marking_window && !_last_full_young_gc)
- // but we can still try to see whether we can find an optimal
- // S-O length
- so_length = calculate_optimal_so_length(_young_list_min_length);
-
-#ifdef TRACE_CALC_YOUNG_CONFIG
+#ifdef TRACE_CALC_YOUNG_LENGTH
// leave this in for debugging, just in case
gclog_or_tty->print_cr("adjusted target length from "
- SIZE_FORMAT " to " SIZE_FORMAT
- ", SO " SIZE_FORMAT,
- _young_list_target_length, _young_list_min_length,
- so_length);
-#endif // TRACE_CALC_YOUNG_CONFIG
-
- _young_list_target_length =
- MAX2(_young_list_min_length, (size_t)1);
- _young_list_so_prefix_length = so_length;
+ SIZE_FORMAT " to " SIZE_FORMAT,
+ _young_list_target_length, _young_list_min_length);
+#endif // TRACE_CALC_YOUNG_LENGTH
+
+ _young_list_target_length = _young_list_min_length;
}
} else {
// we are in a partially-young mode or we've run out of regions (due
// to evacuation failure)
-#ifdef TRACE_CALC_YOUNG_CONFIG
+#ifdef TRACE_CALC_YOUNG_LENGTH
// leave this in for debugging, just in case
gclog_or_tty->print_cr("(partial) setting target to " SIZE_FORMAT
- ", SO " SIZE_FORMAT,
- _young_list_min_length, 0);
-#endif // TRACE_CALC_YOUNG_CONFIG
-
- // we'll do the pause as soon as possible and with no S-O prefix
- // (see above for the reasons behind the latter)
+ _young_list_min_length);
+#endif // TRACE_CALC_YOUNG_LENGTH
+ // we'll do the pause as soon as possible by choosing the minimum
_young_list_target_length =
MAX2(_young_list_min_length, (size_t) 1);
- _young_list_so_prefix_length = 0;
}
_rs_lengths_prediction = rs_lengths;
}
-// This is used by: calculate_optimal_so_length(length). It returns
-// the GC eff and predicted pause time for a particular config
-void
-G1CollectorPolicy::predict_gc_eff(size_t young_length,
- size_t so_length,
- double base_time_ms,
- double* ret_gc_eff,
- double* ret_pause_time_ms) {
- double so_time_ms = predict_scan_only_time_ms(so_length);
- double accum_surv_rate_adj = 0.0;
- if (so_length > 0)
- accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
- double accum_surv_rate =
- accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
- size_t bytes_to_copy =
- (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
- double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
- double young_other_time_ms =
- predict_young_other_time_ms(young_length - so_length);
- double pause_time_ms =
- base_time_ms + so_time_ms + copy_time_ms + young_other_time_ms;
- size_t reclaimed_bytes =
- (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
- double gc_eff = (double) reclaimed_bytes / pause_time_ms;
-
- *ret_gc_eff = gc_eff;
- *ret_pause_time_ms = pause_time_ms;
-}
-
-// This is used by: calculate_young_list_target_config(rs_length). It
-// returns the GC eff of a particular config. It returns false if that
-// config violates any of the end conditions of the search in the
-// calling method, or true upon success. The end conditions were put
-// here since it's called twice and it was best not to replicate them
-// in the caller. Also, passing the parameteres avoids having to
-// recalculate them in the innermost loop.
+// This is used by: calculate_young_list_target_length(rs_length). It
+// returns true iff:
+// the predicted pause time for the given young list will not overflow
+// the target pause time
+// and:
+// the predicted amount of surviving data will not overflow the
+// the amount of free space available for survivor regions.
+//
bool
-G1CollectorPolicy::predict_gc_eff(size_t young_length,
- size_t so_length,
- double base_time_with_so_ms,
- size_t init_free_regions,
- double target_pause_time_ms,
- double* ret_gc_eff) {
- *ret_gc_eff = 0.0;
+G1CollectorPolicy::predict_will_fit(size_t young_length,
+ double base_time_ms,
+ size_t init_free_regions,
+ double target_pause_time_ms) {
if (young_length >= init_free_regions)
// end condition 1: not enough space for the young regions
return false;
double accum_surv_rate_adj = 0.0;
- if (so_length > 0)
- accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
double accum_surv_rate =
accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
+
size_t bytes_to_copy =
(size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
+
double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
+
double young_other_time_ms =
- predict_young_other_time_ms(young_length - so_length);
+ predict_young_other_time_ms(young_length);
+
double pause_time_ms =
- base_time_with_so_ms + copy_time_ms + young_other_time_ms;
+ base_time_ms + copy_time_ms + young_other_time_ms;
if (pause_time_ms > target_pause_time_ms)
// end condition 2: over the target pause time
return false;
- size_t reclaimed_bytes =
- (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
size_t free_bytes =
(init_free_regions - young_length) * HeapRegion::GrainBytes;
@@ -925,9 +604,6 @@
return false;
// success!
- double gc_eff = (double) reclaimed_bytes / pause_time_ms;
- *ret_gc_eff = gc_eff;
-
return true;
}
@@ -944,11 +620,11 @@
void G1CollectorPolicy::check_prediction_validity() {
guarantee( adaptive_young_list_length(), "should not call this otherwise" );
- size_t rs_lengths = _g1->young_list_sampled_rs_lengths();
+ size_t rs_lengths = _g1->young_list()->sampled_rs_lengths();
if (rs_lengths > _rs_lengths_prediction) {
// add 10% to avoid having to recalculate often
size_t rs_lengths_prediction = rs_lengths * 1100 / 1000;
- calculate_young_list_target_config(rs_lengths_prediction);
+ calculate_young_list_target_length(rs_lengths_prediction);
}
}
@@ -970,7 +646,7 @@
#ifndef PRODUCT
bool G1CollectorPolicy::verify_young_ages() {
- HeapRegion* head = _g1->young_list_first_region();
+ HeapRegion* head = _g1->young_list()->first_region();
return
verify_young_ages(head, _short_lived_surv_rate_group);
// also call verify_young_ages on any additional surv rate groups
@@ -1047,7 +723,6 @@
_in_marking_window = false;
_in_marking_window_im = false;
- _short_lived_surv_rate_group->record_scan_only_prefix(0);
_short_lived_surv_rate_group->start_adding_regions();
// also call this on any additional surv rate groups
@@ -1057,11 +732,10 @@
_prev_region_num_tenured = _region_num_tenured;
_free_regions_at_end_of_collection = _g1->free_regions();
- _scan_only_regions_at_end_of_collection = 0;
// Reset survivors SurvRateGroup.
_survivor_surv_rate_group->reset();
calculate_young_list_min_length();
- calculate_young_list_target_config();
+ calculate_young_list_target_length();
}
void G1CollectorPolicy::record_before_bytes(size_t bytes) {
@@ -1110,8 +784,6 @@
for (int i = 0; i < _parallel_gc_threads; ++i) {
_par_last_ext_root_scan_times_ms[i] = -666.0;
_par_last_mark_stack_scan_times_ms[i] = -666.0;
- _par_last_scan_only_times_ms[i] = -666.0;
- _par_last_scan_only_regions_scanned[i] = -666.0;
_par_last_update_rs_start_times_ms[i] = -666.0;
_par_last_update_rs_times_ms[i] = -666.0;
_par_last_update_rs_processed_buffers[i] = -666.0;
@@ -1134,47 +806,13 @@
if (in_young_gc_mode())
_last_young_gc_full = false;
-
// do that for any other surv rate groups
_short_lived_surv_rate_group->stop_adding_regions();
- size_t short_lived_so_length = _young_list_so_prefix_length;
- _short_lived_surv_rate_group->record_scan_only_prefix(short_lived_so_length);
- tag_scan_only(short_lived_so_length);
_survivors_age_table.clear();
assert( verify_young_ages(), "region age verification" );
}
-void G1CollectorPolicy::tag_scan_only(size_t short_lived_scan_only_length) {
- // done in a way that it can be extended for other surv rate groups too...
-
- HeapRegion* head = _g1->young_list_first_region();
- bool finished_short_lived = (short_lived_scan_only_length == 0);
-
- if (finished_short_lived)
- return;
-
- for (HeapRegion* curr = head;
- curr != NULL;
- curr = curr->get_next_young_region()) {
- SurvRateGroup* surv_rate_group = curr->surv_rate_group();
- int age = curr->age_in_surv_rate_group();
-
- if (surv_rate_group == _short_lived_surv_rate_group) {
- if ((size_t)age < short_lived_scan_only_length)
- curr->set_scan_only();
- else
- finished_short_lived = true;
- }
-
-
- if (finished_short_lived)
- return;
- }
-
- guarantee( false, "we should never reach here" );
-}
-
void G1CollectorPolicy::record_mark_closure_time(double mark_closure_time_ms) {
_mark_closure_time_ms = mark_closure_time_ms;
}
@@ -1268,7 +906,7 @@
_last_full_young_gc = true;
_in_marking_window = false;
if (adaptive_young_list_length())
- calculate_young_list_target_config();
+ calculate_young_list_target_length();
}
}
@@ -1503,6 +1141,7 @@
size_t freed_bytes =
_cur_collection_pause_used_at_start_bytes - cur_used_bytes;
size_t surviving_bytes = _collection_set_bytes_used_before - freed_bytes;
+
double survival_fraction =
(double)surviving_bytes/
(double)_collection_set_bytes_used_before;
@@ -1590,9 +1229,6 @@
double ext_root_scan_time = avg_value(_par_last_ext_root_scan_times_ms);
double mark_stack_scan_time = avg_value(_par_last_mark_stack_scan_times_ms);
- double scan_only_time = avg_value(_par_last_scan_only_times_ms);
- double scan_only_regions_scanned =
- sum_of_values(_par_last_scan_only_regions_scanned);
double update_rs_time = avg_value(_par_last_update_rs_times_ms);
double update_rs_processed_buffers =
sum_of_values(_par_last_update_rs_processed_buffers);
@@ -1602,7 +1238,7 @@
double parallel_other_time = _cur_collection_par_time_ms -
(update_rs_time + ext_root_scan_time + mark_stack_scan_time +
- scan_only_time + scan_rs_time + obj_copy_time + termination_time);
+ scan_rs_time + obj_copy_time + termination_time);
if (update_stats) {
MainBodySummary* body_summary = summary->main_body_summary();
guarantee(body_summary != NULL, "should not be null!");
@@ -1613,7 +1249,6 @@
body_summary->record_satb_drain_time_ms(0.0);
body_summary->record_ext_root_scan_time_ms(ext_root_scan_time);
body_summary->record_mark_stack_scan_time_ms(mark_stack_scan_time);
- body_summary->record_scan_only_time_ms(scan_only_time);
body_summary->record_update_rs_time_ms(update_rs_time);
body_summary->record_scan_rs_time_ms(scan_rs_time);
body_summary->record_obj_copy_time_ms(obj_copy_time);
@@ -1667,7 +1302,7 @@
else
other_time_ms -=
update_rs_time +
- ext_root_scan_time + mark_stack_scan_time + scan_only_time +
+ ext_root_scan_time + mark_stack_scan_time +
scan_rs_time + obj_copy_time;
}
@@ -1692,9 +1327,6 @@
_par_last_update_rs_processed_buffers, true);
print_par_stats(2, "Ext Root Scanning", _par_last_ext_root_scan_times_ms);
print_par_stats(2, "Mark Stack Scanning", _par_last_mark_stack_scan_times_ms);
- print_par_stats(2, "Scan-Only Scanning", _par_last_scan_only_times_ms);
- print_par_buffers(3, "Scan-Only Regions",
- _par_last_scan_only_regions_scanned, true);
print_par_stats(2, "Scan RS", _par_last_scan_rs_times_ms);
print_par_stats(2, "Object Copy", _par_last_obj_copy_times_ms);
print_par_stats(2, "Termination", _par_last_termination_times_ms);
@@ -1706,7 +1338,6 @@
(int)update_rs_processed_buffers);
print_stats(1, "Ext Root Scanning", ext_root_scan_time);
print_stats(1, "Mark Stack Scanning", mark_stack_scan_time);
- print_stats(1, "Scan-Only Scanning", scan_only_time);
print_stats(1, "Scan RS", scan_rs_time);
print_stats(1, "Object Copying", obj_copy_time);
}
@@ -1721,6 +1352,8 @@
}
#endif
print_stats(1, "Other", other_time_ms);
+ print_stats(2, "Choose CSet", _recorded_young_cset_choice_time_ms);
+
for (int i = 0; i < _aux_num; ++i) {
if (_cur_aux_times_set[i]) {
char buffer[96];
@@ -1806,16 +1439,6 @@
_cost_per_card_ms_seq->add(cost_per_card_ms);
}
- double cost_per_scan_only_region_ms = 0.0;
- if (scan_only_regions_scanned > 0.0) {
- cost_per_scan_only_region_ms =
- scan_only_time / scan_only_regions_scanned;
- if (_in_marking_window_im)
- _cost_per_scan_only_region_ms_during_cm_seq->add(cost_per_scan_only_region_ms);
- else
- _cost_per_scan_only_region_ms_seq->add(cost_per_scan_only_region_ms);
- }
-
size_t cards_scanned = _g1->cards_scanned();
double cost_per_entry_ms = 0.0;
@@ -1851,7 +1474,7 @@
}
double all_other_time_ms = pause_time_ms -
- (update_rs_time + scan_only_time + scan_rs_time + obj_copy_time +
+ (update_rs_time + scan_rs_time + obj_copy_time +
_mark_closure_time_ms + termination_time);
double young_other_time_ms = 0.0;
@@ -1898,11 +1521,10 @@
if (PREDICTIONS_VERBOSE) {
gclog_or_tty->print_cr("");
gclog_or_tty->print_cr("PREDICTIONS %1.4lf %d "
- "REGIONS %d %d %d %d "
+ "REGIONS %d %d %d "
"PENDING_CARDS %d %d "
"CARDS_SCANNED %d %d "
"RS_LENGTHS %d %d "
- "SCAN_ONLY_SCAN %1.6lf %1.6lf "
"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 "
@@ -1915,12 +1537,10 @@
(last_pause_included_initial_mark) ? 1 : 0,
_recorded_region_num,
_recorded_young_regions,
- _recorded_scan_only_regions,
_recorded_non_young_regions,
_predicted_pending_cards, _pending_cards,
_predicted_cards_scanned, cards_scanned,
_predicted_rs_lengths, _max_rs_lengths,
- _predicted_scan_only_scan_time_ms, scan_only_time,
_predicted_rs_update_time_ms, update_rs_time,
_predicted_rs_scan_time_ms, scan_rs_time,
_predicted_survival_ratio, survival_ratio,
@@ -1945,14 +1565,12 @@
_in_marking_window = new_in_marking_window;
_in_marking_window_im = new_in_marking_window_im;
_free_regions_at_end_of_collection = _g1->free_regions();
- _scan_only_regions_at_end_of_collection = _g1->young_list_length();
calculate_young_list_min_length();
- calculate_young_list_target_config();
+ calculate_young_list_target_length();
// 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>
_target_pause_time_ms = -1.0;
@@ -2007,13 +1625,13 @@
guarantee( adjustment == 0 || adjustment == 1, "invariant" );
G1CollectedHeap* g1h = G1CollectedHeap::heap();
- size_t young_num = g1h->young_list_length();
+ size_t young_num = g1h->young_list()->length();
if (young_num == 0)
return 0.0;
young_num += adjustment;
size_t pending_cards = predict_pending_cards();
- size_t rs_lengths = g1h->young_list_sampled_rs_lengths() +
+ size_t rs_lengths = g1h->young_list()->sampled_rs_lengths() +
predict_rs_length_diff();
size_t card_num;
if (full_young_gcs())
@@ -2097,31 +1715,22 @@
void
G1CollectorPolicy::start_recording_regions() {
_recorded_rs_lengths = 0;
- _recorded_scan_only_regions = 0;
_recorded_young_regions = 0;
_recorded_non_young_regions = 0;
#if PREDICTIONS_VERBOSE
- _predicted_rs_lengths = 0;
- _predicted_cards_scanned = 0;
-
_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(HeapRegion* hr, bool young) {
- if (young) {
- ++_recorded_young_regions;
- } else {
- ++_recorded_non_young_regions;
- }
+G1CollectorPolicy::record_cset_region_info(HeapRegion* hr, bool young) {
#if PREDICTIONS_VERBOSE
- if (young) {
- _recorded_young_bytes += hr->used();
- } else {
+ if (!young) {
_recorded_marked_bytes += hr->max_live_bytes();
}
_predicted_bytes_to_copy += predict_bytes_to_copy(hr);
@@ -2132,12 +1741,37 @@
}
void
-G1CollectorPolicy::record_scan_only_regions(size_t scan_only_length) {
- _recorded_scan_only_regions = scan_only_length;
+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
+}
+
+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();
@@ -2148,8 +1782,6 @@
predict_non_young_card_num(_predicted_rs_lengths);
_recorded_region_num = _recorded_young_regions + _recorded_non_young_regions;
- _predicted_scan_only_scan_time_ms =
- predict_scan_only_time_ms(_recorded_scan_only_regions);
_predicted_rs_update_time_ms =
predict_rs_update_time_ms(_g1->pending_card_num());
_predicted_rs_scan_time_ms =
@@ -2164,7 +1796,6 @@
predict_non_young_other_time_ms(_recorded_non_young_regions);
_predicted_pause_time_ms =
- _predicted_scan_only_scan_time_ms +
_predicted_rs_update_time_ms +
_predicted_rs_scan_time_ms +
_predicted_object_copy_time_ms +
@@ -2454,8 +2085,6 @@
body_summary->get_ext_root_scan_seq());
print_summary(2, "Mark Stack Scanning",
body_summary->get_mark_stack_scan_seq());
- print_summary(2, "Scan-Only Scanning",
- body_summary->get_scan_only_seq());
print_summary(2, "Scan RS", body_summary->get_scan_rs_seq());
print_summary(2, "Object Copy", body_summary->get_obj_copy_seq());
print_summary(2, "Termination", body_summary->get_termination_seq());
@@ -2465,7 +2094,6 @@
body_summary->get_update_rs_seq(),
body_summary->get_ext_root_scan_seq(),
body_summary->get_mark_stack_scan_seq(),
- body_summary->get_scan_only_seq(),
body_summary->get_scan_rs_seq(),
body_summary->get_obj_copy_seq(),
body_summary->get_termination_seq()
@@ -2483,8 +2111,6 @@
body_summary->get_ext_root_scan_seq());
print_summary(1, "Mark Stack Scanning",
body_summary->get_mark_stack_scan_seq());
- print_summary(1, "Scan-Only Scanning",
- body_summary->get_scan_only_seq());
print_summary(1, "Scan RS", body_summary->get_scan_rs_seq());
print_summary(1, "Object Copy", body_summary->get_obj_copy_seq());
}
@@ -2510,7 +2136,6 @@
body_summary->get_update_rs_seq(),
body_summary->get_ext_root_scan_seq(),
body_summary->get_mark_stack_scan_seq(),
- body_summary->get_scan_only_seq(),
body_summary->get_scan_rs_seq(),
body_summary->get_obj_copy_seq()
};
@@ -2604,7 +2229,7 @@
G1CollectorPolicy::should_add_next_region_to_young_list() {
assert(in_young_gc_mode(), "should be in young GC mode");
bool ret;
- size_t young_list_length = _g1->young_list_length();
+ size_t young_list_length = _g1->young_list()->length();
size_t young_list_max_length = _young_list_target_length;
if (G1FixedEdenSize) {
young_list_max_length -= _max_survivor_regions;
@@ -2667,7 +2292,7 @@
assert(_g1->regions_accounted_for(), "Region leakage!");
double max_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
- size_t young_list_length = _g1->young_list_length();
+ size_t young_list_length = _g1->young_list()->length();
size_t young_list_max_length = _young_list_target_length;
if (G1FixedEdenSize) {
young_list_max_length -= _max_survivor_regions;
@@ -2676,7 +2301,7 @@
if (in_young_gc_mode()) {
if (reached_target_length) {
- assert( young_list_length > 0 && _g1->young_list_length() > 0,
+ assert( young_list_length > 0 && _g1->young_list()->length() > 0,
"invariant" );
_target_pause_time_ms = max_pause_time_ms;
return true;
@@ -2937,22 +2562,24 @@
}
}
-// Add the heap region to the collection set and return the conservative
-// estimate of the number of live bytes.
+// Add the heap region at the head of the non-incremental collection set
void G1CollectorPolicy::
add_to_collection_set(HeapRegion* hr) {
+ assert(_inc_cset_build_state == Active, "Precondition");
+ assert(!hr->is_young(), "non-incremental add of young region");
+
if (G1PrintHeapRegions) {
- gclog_or_tty->print_cr("added region to cset %d:["PTR_FORMAT", "PTR_FORMAT"], "
- "top "PTR_FORMAT", young %s",
- hr->hrs_index(), hr->bottom(), hr->end(),
- hr->top(), (hr->is_young()) ? "YES" : "NO");
+ gclog_or_tty->print_cr("added region to cset "
+ "%d:["PTR_FORMAT", "PTR_FORMAT"], "
+ "top "PTR_FORMAT", %s",
+ hr->hrs_index(), hr->bottom(), hr->end(),
+ hr->top(), hr->is_young() ? "YOUNG" : "NOT_YOUNG");
}
if (_g1->mark_in_progress())
_g1->concurrent_mark()->registerCSetRegion(hr);
- assert(!hr->in_collection_set(),
- "should not already be in the CSet");
+ assert(!hr->in_collection_set(), "should not already be in the CSet");
hr->set_in_collection_set(true);
hr->set_next_in_collection_set(_collection_set);
_collection_set = hr;
@@ -2961,10 +2588,230 @@
_g1->register_region_with_in_cset_fast_test(hr);
}
-void
-G1CollectorPolicy_BestRegionsFirst::
-choose_collection_set() {
- double non_young_start_time_sec;
+// Initialize the per-collection-set information
+void G1CollectorPolicy::start_incremental_cset_building() {
+ assert(_inc_cset_build_state == Inactive, "Precondition");
+
+ _inc_cset_head = NULL;
+ _inc_cset_tail = NULL;
+ _inc_cset_size = 0;
+ _inc_cset_bytes_used_before = 0;
+
+ if (in_young_gc_mode()) {
+ _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;
+}
+
+void G1CollectorPolicy::add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length) {
+ // This routine is used when:
+ // * adding survivor regions to the incremental cset at the end of an
+ // evacuation pause,
+ // * adding the current allocation region to the incremental cset
+ // when it is retired, and
+ // * updating existing policy information for a region in the
+ // incremental cset via young list RSet sampling.
+ // Therefore this routine may be called at a safepoint by the
+ // VM thread, or in-between safepoints by mutator threads (when
+ // retiring the current allocation region) or a concurrent
+ // refine thread (RSet sampling).
+
+ double region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, true);
+ size_t used_bytes = hr->used();
+
+ _inc_cset_recorded_rs_lengths += rs_length;
+ _inc_cset_predicted_elapsed_time_ms += region_elapsed_time_ms;
+
+ _inc_cset_bytes_used_before += 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_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) {
+ // This routine is currently only called as part of the updating of
+ // existing policy information for regions in the incremental cset that
+ // is performed by the concurrent refine thread(s) as part of young list
+ // RSet sampling. Therefore we should not be at a safepoint.
+
+ assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
+ assert(hr->is_young(), "it should be");
+
+ size_t used_bytes = hr->used();
+ size_t old_rs_length = hr->recorded_rs_length();
+ double old_elapsed_time_ms = hr->predicted_elapsed_time_ms();
+
+ // Subtract the old recorded/predicted policy information for
+ // the given heap region from the collection set info.
+ _inc_cset_recorded_rs_lengths -= old_rs_length;
+ _inc_cset_predicted_elapsed_time_ms -= old_elapsed_time_ms;
+
+ _inc_cset_bytes_used_before -= used_bytes;
+
+ // 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) {
+ // Update the collection set information that is dependent on the new RS length
+ assert(hr->is_young(), "Precondition");
+
+ remove_from_incremental_cset_info(hr);
+ add_to_incremental_cset_info(hr, new_rs_length);
+}
+
+void G1CollectorPolicy::add_region_to_incremental_cset_common(HeapRegion* hr) {
+ assert( hr->is_young(), "invariant");
+ assert( hr->young_index_in_cset() == -1, "invariant" );
+ assert(_inc_cset_build_state == Active, "Precondition");
+
+ // We need to clear and set the cached recorded/cached collection set
+ // information in the heap region here (before the region gets added
+ // to the collection set). An individual heap region's cached values
+ // are calculated, aggregated with the policy collection set info,
+ // and cached in the heap region here (initially) and (subsequently)
+ // by the Young List sampling code.
+
+ size_t rs_length = hr->rem_set()->occupied();
+ add_to_incremental_cset_info(hr, rs_length);
+
+ HeapWord* hr_end = hr->end();
+ _inc_cset_max_finger = MAX2(_inc_cset_max_finger, hr_end);
+
+ assert(!hr->in_collection_set(), "invariant");
+ 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
+void G1CollectorPolicy::add_region_to_incremental_cset_rhs(HeapRegion* hr) {
+ // We should only ever be appending survivors at the end of a pause
+ assert( hr->is_survivor(), "Logic");
+
+ // Do the 'common' stuff
+ add_region_to_incremental_cset_common(hr);
+
+ // Now add the region at the right hand side
+ if (_inc_cset_tail == NULL) {
+ assert(_inc_cset_head == NULL, "invariant");
+ _inc_cset_head = hr;
+ } else {
+ _inc_cset_tail->set_next_in_collection_set(hr);
+ }
+ _inc_cset_tail = hr;
+
+ if (G1PrintHeapRegions) {
+ gclog_or_tty->print_cr(" added region to incremental cset (RHS) "
+ "%d:["PTR_FORMAT", "PTR_FORMAT"], "
+ "top "PTR_FORMAT", young %s",
+ hr->hrs_index(), hr->bottom(), hr->end(),
+ hr->top(), (hr->is_young()) ? "YES" : "NO");
+ }
+}
+
+// Add the region to the LHS of the incremental cset
+void G1CollectorPolicy::add_region_to_incremental_cset_lhs(HeapRegion* hr) {
+ // Survivors should be added to the RHS at the end of a pause
+ assert(!hr->is_survivor(), "Logic");
+
+ // Do the 'common' stuff
+ add_region_to_incremental_cset_common(hr);
+
+ // Add the region at the left hand side
+ hr->set_next_in_collection_set(_inc_cset_head);
+ if (_inc_cset_head == NULL) {
+ assert(_inc_cset_tail == NULL, "Invariant");
+ _inc_cset_tail = hr;
+ }
+ _inc_cset_head = hr;
+
+ if (G1PrintHeapRegions) {
+ gclog_or_tty->print_cr(" added region to incremental cset (LHS) "
+ "%d:["PTR_FORMAT", "PTR_FORMAT"], "
+ "top "PTR_FORMAT", young %s",
+ hr->hrs_index(), hr->bottom(), hr->end(),
+ hr->top(), (hr->is_young()) ? "YES" : "NO");
+ }
+}
+
+#ifndef PRODUCT
+void G1CollectorPolicy::print_collection_set(HeapRegion* list_head, outputStream* st) {
+ assert(list_head == inc_cset_head() || list_head == collection_set(), "must be");
+
+ st->print_cr("\nCollection_set:");
+ HeapRegion* csr = list_head;
+ while (csr != NULL) {
+ HeapRegion* next = csr->next_in_collection_set();
+ assert(csr->in_collection_set(), "bad CS");
+ st->print_cr(" [%08x-%08x], t: %08x, P: %08x, N: %08x, C: %08x, "
+ "age: %4d, y: %d, surv: %d",
+ csr->bottom(), csr->end(),
+ csr->top(),
+ csr->prev_top_at_mark_start(),
+ csr->next_top_at_mark_start(),
+ csr->top_at_conc_mark_count(),
+ csr->age_in_surv_rate_group_cond(),
+ csr->is_young(),
+ csr->is_survivor());
+ csr = next;
+ }
+}
+#endif // !PRODUCT
+
+bool
+G1CollectorPolicy_BestRegionsFirst::choose_collection_set() {
+ // Set this here - in case we're not doing young collections.
+ double non_young_start_time_sec = os::elapsedTime();
+
+ // The result that this routine will return. This will be set to
+ // false if:
+ // * we're doing a young or partially young collection and we
+ // have added the youg regions to collection set, or
+ // * we add old regions to the collection set.
+ bool abandon_collection = true;
+
start_recording_regions();
guarantee(_target_pause_time_ms > -1.0
@@ -3017,47 +2864,79 @@
if (G1PolicyVerbose > 0) {
gclog_or_tty->print_cr("Adding %d young regions to the CSet",
- _g1->young_list_length());
+ _g1->young_list()->length());
}
+
_young_cset_length = 0;
_last_young_gc_full = full_young_gcs() ? true : false;
+
if (_last_young_gc_full)
++_full_young_pause_num;
else
++_partial_young_pause_num;
- hr = _g1->pop_region_from_young_list();
+
+ // The young list is laid with the survivor regions from the previous
+ // pause are appended to the RHS of the young list, i.e.
+ // [Newly Young Regions ++ Survivors from last pause].
+
+ hr = _g1->young_list()->first_survivor_region();
while (hr != NULL) {
-
- assert( hr->young_index_in_cset() == -1, "invariant" );
- assert( hr->age_in_surv_rate_group() != -1, "invariant" );
- hr->set_young_index_in_cset((int) _young_cset_length);
-
- ++_young_cset_length;
- double predicted_time_ms = predict_region_elapsed_time_ms(hr, true);
- time_remaining_ms -= predicted_time_ms;
- predicted_pause_time_ms += predicted_time_ms;
- assert(!hr->in_collection_set(), "invariant");
- add_to_collection_set(hr);
- record_cset_region(hr, true);
- max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
- if (G1PolicyVerbose > 0) {
- gclog_or_tty->print_cr(" Added [" PTR_FORMAT ", " PTR_FORMAT") to CS.",
- hr->bottom(), hr->end());
- gclog_or_tty->print_cr(" (" SIZE_FORMAT " KB left in heap.)",
- max_live_bytes/K);
- }
- hr = _g1->pop_region_from_young_list();
+ assert(hr->is_survivor(), "badly formed young list");
+ hr->set_young();
+ hr = hr->get_next_young_region();
}
- record_scan_only_regions(_g1->young_list_scan_only_length());
+ // Clear the fields that point to the survivor list - they are
+ // all young now.
+ _g1->young_list()->clear_survivors();
+
+ 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;
+
+ // For young regions in the collection set, we assume the worst
+ // case of complete survival
+ max_live_bytes -= _inc_cset_size * HeapRegion::GrainBytes;
+
+ time_remaining_ms -= _inc_cset_predicted_elapsed_time_ms;
+ predicted_pause_time_ms += _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
+
+ if (G1PolicyVerbose > 0) {
+ gclog_or_tty->print_cr(" Added " PTR_FORMAT " Young Regions to CS.",
+ _inc_cset_size);
+ gclog_or_tty->print_cr(" (" SIZE_FORMAT " KB left in heap.)",
+ max_live_bytes/K);
+ }
+
+ assert(_inc_cset_size == _g1->young_list()->length(), "Invariant");
+ if (_inc_cset_size > 0) {
+ assert(_collection_set != NULL, "Invariant");
+ abandon_collection = false;
+ }
double young_end_time_sec = os::elapsedTime();
_recorded_young_cset_choice_time_ms =
(young_end_time_sec - young_start_time_sec) * 1000.0;
- non_young_start_time_sec = os::elapsedTime();
-
- if (_young_cset_length > 0 && _last_young_gc_full) {
+ // We are doing young collections so reset this.
+ non_young_start_time_sec = young_end_time_sec;
+
+ // Note we can use either _collection_set_size or
+ // _young_cset_length here
+ if (_collection_set_size > 0 && _last_young_gc_full) {
// don't bother adding more regions...
goto choose_collection_set_end;
}
@@ -3067,6 +2946,11 @@
bool should_continue = true;
NumberSeq seq;
double avg_prediction = 100000000000000000.0; // something very large
+
+ // Save the current size of the collection set to detect
+ // if we actually added any old regions.
+ size_t n_young_regions = _collection_set_size;
+
do {
hr = _collectionSetChooser->getNextMarkedRegion(time_remaining_ms,
avg_prediction);
@@ -3075,7 +2959,7 @@
time_remaining_ms -= predicted_time_ms;
predicted_pause_time_ms += predicted_time_ms;
add_to_collection_set(hr);
- record_cset_region(hr, false);
+ record_non_young_cset_region(hr);
max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
if (G1PolicyVerbose > 0) {
gclog_or_tty->print_cr(" (" SIZE_FORMAT " KB left in heap.)",
@@ -3093,9 +2977,17 @@
if (!adaptive_young_list_length() &&
_collection_set_size < _young_list_fixed_length)
_should_revert_to_full_young_gcs = true;
+
+ if (_collection_set_size > n_young_regions) {
+ // We actually added old regions to the collection set
+ // so we are not abandoning this collection.
+ abandon_collection = false;
+ }
}
choose_collection_set_end:
+ stop_incremental_cset_building();
+
count_CS_bytes_used();
end_recording_regions();
@@ -3103,6 +2995,8 @@
double non_young_end_time_sec = os::elapsedTime();
_recorded_non_young_cset_choice_time_ms =
(non_young_end_time_sec - non_young_start_time_sec) * 1000.0;
+
+ return abandon_collection;
}
void G1CollectorPolicy_BestRegionsFirst::record_full_collection_end() {
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -61,7 +61,6 @@
define_num_seq(parallel) // parallel only
define_num_seq(ext_root_scan)
define_num_seq(mark_stack_scan)
- define_num_seq(scan_only)
define_num_seq(update_rs)
define_num_seq(scan_rs)
define_num_seq(scan_new_refs) // Only for temp use; added to
@@ -174,8 +173,6 @@
double* _par_last_ext_root_scan_times_ms;
double* _par_last_mark_stack_scan_times_ms;
- double* _par_last_scan_only_times_ms;
- double* _par_last_scan_only_regions_scanned;
double* _par_last_update_rs_start_times_ms;
double* _par_last_update_rs_times_ms;
double* _par_last_update_rs_processed_buffers;
@@ -196,7 +193,6 @@
bool _adaptive_young_list_length;
size_t _young_list_min_length;
size_t _young_list_target_length;
- size_t _young_list_so_prefix_length;
size_t _young_list_fixed_length;
size_t _young_cset_length;
@@ -234,7 +230,6 @@
TruncatedSeq* _pending_card_diff_seq;
TruncatedSeq* _rs_length_diff_seq;
TruncatedSeq* _cost_per_card_ms_seq;
- TruncatedSeq* _cost_per_scan_only_region_ms_seq;
TruncatedSeq* _fully_young_cards_per_entry_ratio_seq;
TruncatedSeq* _partially_young_cards_per_entry_ratio_seq;
TruncatedSeq* _cost_per_entry_ms_seq;
@@ -249,19 +244,16 @@
TruncatedSeq* _rs_lengths_seq;
TruncatedSeq* _cost_per_byte_ms_during_cm_seq;
- TruncatedSeq* _cost_per_scan_only_region_ms_during_cm_seq;
TruncatedSeq* _young_gc_eff_seq;
TruncatedSeq* _max_conc_overhead_seq;
size_t _recorded_young_regions;
- size_t _recorded_scan_only_regions;
size_t _recorded_non_young_regions;
size_t _recorded_region_num;
size_t _free_regions_at_end_of_collection;
- size_t _scan_only_regions_at_end_of_collection;
size_t _recorded_rs_lengths;
size_t _max_rs_lengths;
@@ -277,7 +269,6 @@
double _predicted_survival_ratio;
double _predicted_rs_update_time_ms;
double _predicted_rs_scan_time_ms;
- double _predicted_scan_only_scan_time_ms;
double _predicted_object_copy_time_ms;
double _predicted_constant_other_time_ms;
double _predicted_young_other_time_ms;
@@ -344,8 +335,6 @@
bool verify_young_ages();
#endif // PRODUCT
- void tag_scan_only(size_t short_lived_scan_only_length);
-
double get_new_prediction(TruncatedSeq* seq) {
return MAX2(seq->davg() + sigma() * seq->dsd(),
seq->davg() * confidence_factor(seq->num()));
@@ -431,23 +420,6 @@
get_new_prediction(_partially_young_cost_per_entry_ms_seq);
}
- double predict_scan_only_time_ms_during_cm(size_t scan_only_region_num) {
- if (_cost_per_scan_only_region_ms_during_cm_seq->num() < 3)
- return 1.5 * (double) scan_only_region_num *
- get_new_prediction(_cost_per_scan_only_region_ms_seq);
- else
- return (double) scan_only_region_num *
- get_new_prediction(_cost_per_scan_only_region_ms_during_cm_seq);
- }
-
- double predict_scan_only_time_ms(size_t scan_only_region_num) {
- if (_in_marking_window_im)
- return predict_scan_only_time_ms_during_cm(scan_only_region_num);
- else
- return (double) scan_only_region_num *
- get_new_prediction(_cost_per_scan_only_region_ms_seq);
- }
-
double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) {
if (_cost_per_byte_ms_during_cm_seq->num() < 3)
return 1.1 * (double) bytes_to_copy *
@@ -490,24 +462,21 @@
size_t predict_bytes_to_copy(HeapRegion* hr);
double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);
- // for use by: calculate_optimal_so_length(length)
- void predict_gc_eff(size_t young_region_num,
- size_t so_length,
- double base_time_ms,
- double *gc_eff,
- double *pause_time_ms);
-
- // for use by: calculate_young_list_target_config(rs_length)
- bool predict_gc_eff(size_t young_region_num,
- size_t so_length,
- double base_time_with_so_ms,
- size_t init_free_regions,
- double target_pause_time_ms,
- double* gc_eff);
+ // for use by: calculate_young_list_target_length(rs_length)
+ bool predict_will_fit(size_t young_region_num,
+ double base_time_ms,
+ size_t init_free_regions,
+ double target_pause_time_ms);
void start_recording_regions();
- void record_cset_region(HeapRegion* hr, bool young);
- void record_scan_only_regions(size_t scan_only_length);
+ void record_cset_region_info(HeapRegion* hr, bool young);
+ void record_non_young_cset_region(HeapRegion* hr);
+
+ 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) {
@@ -638,11 +607,74 @@
void update_recent_gc_times(double end_time_sec, double elapsed_ms);
// The head of the list (via "next_in_collection_set()") representing the
- // current collection set.
+ // current collection set. Set from the incrementally built collection
+ // 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.
size_t _collection_set_bytes_used_before;
+ // The associated information that is maintained while the incremental
+ // collection set is being built with young regions. Used to populate
+ // the recorded info for the evacuation pause.
+
+ enum CSetBuildType {
+ Active, // We are actively building the collection set
+ Inactive // We are not actively building the collection set
+ };
+
+ CSetBuildType _inc_cset_build_state;
+
+ // The head of the incrementally built collection set.
+ HeapRegion* _inc_cset_head;
+
+ // 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.
+ size_t _inc_cset_bytes_used_before;
+
+ // 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).
+ size_t _inc_cset_recorded_rs_lengths;
+
+ // The predicted elapsed time it will take to collect the regions
+ // in the collection set (updated by the periodic sampling of the
+ // 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;
+
// Info about marking.
int _n_marks; // Sticky at 2, so we know when we've done at least 2.
@@ -761,9 +793,8 @@
double _mark_closure_time_ms;
void calculate_young_list_min_length();
- void calculate_young_list_target_config();
- void calculate_young_list_target_config(size_t rs_lengths);
- size_t calculate_optimal_so_length(size_t young_list_length);
+ void calculate_young_list_target_length();
+ void calculate_young_list_target_length(size_t rs_lengths);
public:
@@ -868,11 +899,6 @@
_par_last_mark_stack_scan_times_ms[worker_i] = ms;
}
- void record_scan_only_time(int worker_i, double ms, int n) {
- _par_last_scan_only_times_ms[worker_i] = ms;
- _par_last_scan_only_regions_scanned[worker_i] = (double) n;
- }
-
void record_satb_drain_time(double ms) {
_cur_satb_drain_time_ms = ms;
_satb_drain_time_set = true;
@@ -987,20 +1013,67 @@
// Choose a new collection set. Marks the chosen regions as being
// "in_collection_set", and links them together. The head and number of
// the collection set are available via access methods.
- virtual void choose_collection_set() = 0;
-
- void clear_collection_set() { _collection_set = NULL; }
+ virtual bool choose_collection_set() = 0;
// The head of the list (via "next_in_collection_set()") representing the
// current collection set.
HeapRegion* collection_set() { return _collection_set; }
+ 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);
+ // Incremental CSet Support
+
+ // The head of the incrementally built collection set.
+ HeapRegion* inc_cset_head() { return _inc_cset_head; }
+
+ // 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();
+
+ void clear_incremental_cset() {
+ _inc_cset_head = NULL;
+ _inc_cset_tail = NULL;
+ }
+
+ // Stop adding regions to the incremental collection set
+ void stop_incremental_cset_building() { _inc_cset_build_state = Inactive; }
+
+ // Add/remove information about hr to the aggregated information
+ // for the incrementally built collection set.
+ void add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length);
+ void remove_from_incremental_cset_info(HeapRegion* hr);
+
+ // Update information about hr in the aggregated information for
+ // the incrementally built collection set.
+ void update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length);
+
+private:
+ // Update the incremental cset information when adding a region
+ // (should not be called directly).
+ void add_region_to_incremental_cset_common(HeapRegion* hr);
+
+public:
+ // Add hr to the LHS of the incremental collection set.
+ void add_region_to_incremental_cset_lhs(HeapRegion* hr);
+
+ // Add hr to the RHS of the incremental collection set.
+ void add_region_to_incremental_cset_rhs(HeapRegion* hr);
+
+#ifndef PRODUCT
+ void print_collection_set(HeapRegion* list_head, outputStream* st);
+#endif // !PRODUCT
+
bool initiate_conc_mark_if_possible() { return _initiate_conc_mark_if_possible; }
void set_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = true; }
void clear_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = false; }
@@ -1191,7 +1264,7 @@
// If the estimated is less then desirable, resize if possible.
void expand_if_possible(size_t numRegions);
- virtual void choose_collection_set();
+ virtual bool choose_collection_set();
virtual void record_collection_pause_start(double start_time_sec,
size_t start_used);
virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,
--- a/hotspot/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -31,6 +31,12 @@
bool clear_all_softrefs) {
assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
+ SharedHeap* sh = SharedHeap::heap();
+#ifdef ASSERT
+ if (sh->collector_policy()->should_clear_all_soft_refs()) {
+ assert(clear_all_softrefs, "Policy should have been checked earler");
+ }
+#endif
// hook up weak ref data so it can be used during Mark-Sweep
assert(GenMarkSweep::ref_processor() == NULL, "no stomping");
assert(rp != NULL, "should be non-NULL");
@@ -44,7 +50,6 @@
// Increment the invocation count for the permanent generation, since it is
// implicitly collected whenever we do a full mark sweep collection.
- SharedHeap* sh = SharedHeap::heap();
sh->perm_gen()->stat_record()->invocations++;
bool marked_for_unloading = false;
--- a/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -28,9 +28,6 @@
#define G1_FLAGS(develop, develop_pd, product, product_pd, diagnostic, experimental, notproduct, manageable, product_rw) \
\
- product(intx, G1ParallelGCAllocBufferSize, 8*K, \
- "Size of parallel G1 allocation buffers in to-space.") \
- \
product(intx, G1ConfidencePercent, 50, \
"Confidence level for MMU/pause predictions") \
\
@@ -229,10 +226,6 @@
"the number of regions for which we'll print a surv rate " \
"summary.") \
\
- develop(bool, G1UseScanOnlyPrefix, false, \
- "It determines whether the system will calculate an optimum " \
- "scan-only set.") \
- \
product(intx, G1ReservePercent, 10, \
"It determines the minimum reserve we should have in the heap " \
"to minimize the probability of promotion failure.") \
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -75,6 +75,16 @@
virtual void do_oop(narrowOop* p) { do_oop_work(p); }
virtual void do_oop( oop* p) { do_oop_work(p); }
+ void print_object(outputStream* out, oop obj) {
+#ifdef PRODUCT
+ klassOop k = obj->klass();
+ const char* class_name = instanceKlass::cast(k)->external_name();
+ out->print_cr("class name %s", class_name);
+#else // PRODUCT
+ obj->print_on(out);
+#endif // PRODUCT
+ }
+
template <class T> void do_oop_work(T* p) {
assert(_containing_obj != NULL, "Precondition");
assert(!_g1h->is_obj_dead_cond(_containing_obj, _use_prev_marking),
@@ -90,21 +100,29 @@
gclog_or_tty->print_cr("----------");
}
if (!_g1h->is_in_closed_subset(obj)) {
- gclog_or_tty->print_cr("Field "PTR_FORMAT
- " of live obj "PTR_FORMAT
- " points to obj "PTR_FORMAT
- " not in the heap.",
- p, (void*) _containing_obj, (void*) obj);
- } else {
+ HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
gclog_or_tty->print_cr("Field "PTR_FORMAT
- " of live obj "PTR_FORMAT
- " points to dead obj "PTR_FORMAT".",
- p, (void*) _containing_obj, (void*) obj);
+ " of live obj "PTR_FORMAT" in region "
+ "["PTR_FORMAT", "PTR_FORMAT")",
+ p, (void*) _containing_obj,
+ from->bottom(), from->end());
+ print_object(gclog_or_tty, _containing_obj);
+ gclog_or_tty->print_cr("points to obj "PTR_FORMAT" not in the heap",
+ (void*) obj);
+ } else {
+ HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
+ HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj);
+ gclog_or_tty->print_cr("Field "PTR_FORMAT
+ " of live obj "PTR_FORMAT" in region "
+ "["PTR_FORMAT", "PTR_FORMAT")",
+ p, (void*) _containing_obj,
+ from->bottom(), from->end());
+ print_object(gclog_or_tty, _containing_obj);
+ gclog_or_tty->print_cr("points to dead obj "PTR_FORMAT" in region "
+ "["PTR_FORMAT", "PTR_FORMAT")",
+ (void*) obj, to->bottom(), to->end());
+ print_object(gclog_or_tty, obj);
}
- gclog_or_tty->print_cr("Live obj:");
- _containing_obj->print_on(gclog_or_tty);
- gclog_or_tty->print_cr("Bad referent:");
- obj->print_on(gclog_or_tty);
gclog_or_tty->print_cr("----------");
_failures = true;
failed = true;
@@ -432,7 +450,9 @@
_young_type(NotYoung), _next_young_region(NULL),
_next_dirty_cards_region(NULL),
_young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1),
- _rem_set(NULL), _zfs(NotZeroFilled)
+ _rem_set(NULL), _zfs(NotZeroFilled),
+ _recorded_rs_length(0), _predicted_elapsed_time_ms(0),
+ _predicted_bytes_to_copy(0)
{
_orig_end = mr.end();
// Note that initialize() will set the start of the unmarked area of the
@@ -715,7 +735,7 @@
else
st->print(" ");
if (is_young())
- st->print(is_scan_only() ? " SO" : (is_survivor() ? " SU" : " Y "));
+ st->print(is_survivor() ? " SU" : " Y ");
else
st->print(" ");
if (is_empty())
@@ -723,6 +743,8 @@
else
st->print(" ");
st->print(" %5d", _gc_time_stamp);
+ st->print(" PTAMS "PTR_FORMAT" NTAMS "PTR_FORMAT,
+ prev_top_at_mark_start(), next_top_at_mark_start());
G1OffsetTableContigSpace::print_on(st);
}
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -247,7 +247,6 @@
enum YoungType {
NotYoung, // a region is not young
- ScanOnly, // a region is young and scan-only
Young, // a region is young
Survivor // a region is young and it contains
// survivor
@@ -292,6 +291,20 @@
_young_type = new_type;
}
+ // Cached attributes used in the collection set policy information
+
+ // The RSet length that was added to the total value
+ // for the collection set.
+ size_t _recorded_rs_length;
+
+ // The predicted elapsed time that was added to total value
+ // for the collection set.
+ double _predicted_elapsed_time_ms;
+
+ // The predicted number of bytes to copy that was added to
+ // the total value for the collection set.
+ size_t _predicted_bytes_to_copy;
+
public:
// If "is_zeroed" is "true", the region "mr" can be assumed to contain zeros.
HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray,
@@ -614,7 +627,6 @@
// </PREDICTION>
bool is_young() const { return _young_type != NotYoung; }
- bool is_scan_only() const { return _young_type == ScanOnly; }
bool is_survivor() const { return _young_type == Survivor; }
int young_index_in_cset() const { return _young_index_in_cset; }
@@ -629,12 +641,6 @@
return _surv_rate_group->age_in_group(_age_index);
}
- void recalculate_age_in_surv_rate_group() {
- assert( _surv_rate_group != NULL, "pre-condition" );
- assert( _age_index > -1, "pre-condition" );
- _age_index = _surv_rate_group->recalculate_age_index(_age_index);
- }
-
void record_surv_words_in_group(size_t words_survived) {
assert( _surv_rate_group != NULL, "pre-condition" );
assert( _age_index > -1, "pre-condition" );
@@ -676,8 +682,6 @@
void set_young() { set_young_type(Young); }
- void set_scan_only() { set_young_type(ScanOnly); }
-
void set_survivor() { set_young_type(Survivor); }
void set_not_young() { set_young_type(NotYoung); }
@@ -775,6 +779,22 @@
_zero_filler = NULL;
}
+ size_t recorded_rs_length() const { return _recorded_rs_length; }
+ double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; }
+ size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; }
+
+ void set_recorded_rs_length(size_t rs_length) {
+ _recorded_rs_length = rs_length;
+ }
+
+ void set_predicted_elapsed_time_ms(double ms) {
+ _predicted_elapsed_time_ms = ms;
+ }
+
+ void set_predicted_bytes_to_copy(size_t bytes) {
+ _predicted_bytes_to_copy = bytes;
+ }
+
#define HeapRegion_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \
virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DECL)
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -662,8 +662,6 @@
prt = PosParPRT::alloc(from_hr);
}
prt->init(from_hr);
- // Record the outgoing pointer in the from_region's outgoing bitmap.
- from_hr->rem_set()->add_outgoing_reference(hr());
PosParPRT* first_prt = _fine_grain_regions[ind];
prt->set_next(first_prt); // XXX Maybe move to init?
@@ -1073,11 +1071,7 @@
HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
HeapRegion* hr)
- : _bosa(bosa), _other_regions(hr),
- _outgoing_region_map(G1CollectedHeap::heap()->max_regions(),
- false /* in-resource-area */),
- _iter_state(Unclaimed)
-{}
+ : _bosa(bosa), _other_regions(hr), _iter_state(Unclaimed) { }
void HeapRegionRemSet::setup_remset_size() {
@@ -1148,30 +1142,11 @@
PosParPRT::par_contract_all();
}
-void HeapRegionRemSet::add_outgoing_reference(HeapRegion* to_hr) {
- _outgoing_region_map.par_at_put(to_hr->hrs_index(), 1);
-}
-
void HeapRegionRemSet::clear() {
- clear_outgoing_entries();
- _outgoing_region_map.clear();
_other_regions.clear();
assert(occupied() == 0, "Should be clear.");
}
-void HeapRegionRemSet::clear_outgoing_entries() {
- G1CollectedHeap* g1h = G1CollectedHeap::heap();
- size_t i = _outgoing_region_map.get_next_one_offset(0);
- while (i < _outgoing_region_map.size()) {
- HeapRegion* to_region = g1h->region_at(i);
- if (!to_region->in_collection_set()) {
- to_region->rem_set()->clear_incoming_entry(hr());
- }
- i = _outgoing_region_map.get_next_one_offset(i+1);
- }
-}
-
-
void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
BitMap* region_bm, BitMap* card_bm) {
_other_regions.scrub(ctbs, region_bm, card_bm);
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -179,13 +179,6 @@
OtherRegionsTable _other_regions;
- // One set bit for every region that has an entry for this one.
- BitMap _outgoing_region_map;
-
- // Clear entries for the current region in any rem sets named in
- // the _outgoing_region_map.
- void clear_outgoing_entries();
-
enum ParIterState { Unclaimed, Claimed, Complete };
volatile ParIterState _iter_state;
volatile jlong _iter_claimed;
@@ -243,10 +236,6 @@
_other_regions.add_reference(from, tid);
}
- // Records the fact that the current region contains an outgoing
- // reference into "to_hr".
- void add_outgoing_reference(HeapRegion* to_hr);
-
// Removes any entries shown by the given bitmaps to contain only dead
// objects.
void scrub(CardTableModRefBS* ctbs, BitMap* region_bm, BitMap* card_bm);
--- a/hotspot/src/share/vm/gc_implementation/g1/survRateGroup.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/survRateGroup.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -55,7 +55,6 @@
void SurvRateGroup::reset()
{
_all_regions_allocated = 0;
- _scan_only_prefix = 0;
_setup_seq_num = 0;
_stats_arrays_length = 0;
_accum_surv_rate = 0.0;
@@ -74,7 +73,7 @@
void
SurvRateGroup::start_adding_regions() {
_setup_seq_num = _stats_arrays_length;
- _region_num = _scan_only_prefix;
+ _region_num = 0;
_accum_surv_rate = 0.0;
#if 0
@@ -164,12 +163,6 @@
}
void
-SurvRateGroup::record_scan_only_prefix(size_t scan_only_prefix) {
- guarantee( scan_only_prefix <= _region_num, "pre-condition" );
- _scan_only_prefix = scan_only_prefix;
-}
-
-void
SurvRateGroup::record_surviving_words(int age_in_group, size_t surv_words) {
guarantee( 0 <= age_in_group && (size_t) age_in_group < _region_num,
"pre-condition" );
@@ -218,13 +211,12 @@
#ifndef PRODUCT
void
SurvRateGroup::print() {
- gclog_or_tty->print_cr("Surv Rate Group: %s (%d entries, %d scan-only)",
- _name, _region_num, _scan_only_prefix);
+ gclog_or_tty->print_cr("Surv Rate Group: %s (%d entries)",
+ _name, _region_num);
for (size_t i = 0; i < _region_num; ++i) {
- gclog_or_tty->print_cr(" age %4d surv rate %6.2lf %% pred %6.2lf %%%s",
+ gclog_or_tty->print_cr(" age %4d surv rate %6.2lf %% pred %6.2lf %%",
i, _surv_rate[i] * 100.0,
- _g1p->get_new_prediction(_surv_rate_pred[i]) * 100.0,
- (i < _scan_only_prefix) ? " S-O" : " ");
+ _g1p->get_new_prediction(_surv_rate_pred[i]) * 100.0);
}
}
--- a/hotspot/src/share/vm/gc_implementation/g1/survRateGroup.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/survRateGroup.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -41,7 +41,6 @@
int _all_regions_allocated;
size_t _region_num;
- size_t _scan_only_prefix;
size_t _setup_seq_num;
public:
@@ -51,13 +50,11 @@
void reset();
void start_adding_regions();
void stop_adding_regions();
- void record_scan_only_prefix(size_t scan_only_prefix);
void record_surviving_words(int age_in_group, size_t surv_words);
void all_surviving_words_recorded(bool propagate);
const char* name() { return _name; }
size_t region_num() { return _region_num; }
- size_t scan_only_length() { return _scan_only_prefix; }
double accum_surv_rate_pred(int age) {
assert(age >= 0, "must be");
if ((size_t)age < _stats_arrays_length)
@@ -82,17 +79,12 @@
int next_age_index();
int age_in_group(int age_index) {
- int ret = (int) (_all_regions_allocated - age_index);
+ int ret = (int) (_all_regions_allocated - age_index);
assert( ret >= 0, "invariant" );
return ret;
}
- int recalculate_age_index(int age_index) {
- int new_age_index = (int) _scan_only_prefix - age_in_group(age_index);
- guarantee( new_age_index >= 0, "invariant" );
- return new_age_index;
- }
void finished_recalculating_age_indexes() {
- _all_regions_allocated = (int) _scan_only_prefix;
+ _all_regions_allocated = 0;
}
#ifndef PRODUCT
--- a/hotspot/src/share/vm/gc_implementation/includeDB_gc_parallelScavenge Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/includeDB_gc_parallelScavenge Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
//
-// Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+// Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -161,8 +161,10 @@
parMarkBitMap.hpp bitMap.inline.hpp
parMarkBitMap.hpp psVirtualspace.hpp
+psAdaptiveSizePolicy.cpp collectorPolicy.hpp
psAdaptiveSizePolicy.cpp gcPolicyCounters.hpp
psAdaptiveSizePolicy.cpp gcCause.hpp
+psAdaptiveSizePolicy.cpp generationSizer.hpp
psAdaptiveSizePolicy.cpp psAdaptiveSizePolicy.hpp
psAdaptiveSizePolicy.cpp psGCAdaptivePolicyCounters.hpp
psAdaptiveSizePolicy.cpp psScavenge.hpp
@@ -215,6 +217,7 @@
psMarkSweep.cpp fprofiler.hpp
psMarkSweep.cpp gcCause.hpp
psMarkSweep.cpp gcLocker.inline.hpp
+psMarkSweep.cpp generationSizer.hpp
psMarkSweep.cpp isGCActiveMark.hpp
psMarkSweep.cpp oop.inline.hpp
psMarkSweep.cpp memoryService.hpp
@@ -256,6 +259,7 @@
psParallelCompact.cpp gcCause.hpp
psParallelCompact.cpp gcLocker.inline.hpp
psParallelCompact.cpp gcTaskManager.hpp
+psParallelCompact.cpp generationSizer.hpp
psParallelCompact.cpp isGCActiveMark.hpp
psParallelCompact.cpp management.hpp
psParallelCompact.cpp memoryService.hpp
@@ -344,10 +348,12 @@
psScavenge.cpp psAdaptiveSizePolicy.hpp
psScavenge.cpp biasedLocking.hpp
psScavenge.cpp cardTableExtension.hpp
+psScavenge.cpp collectorPolicy.hpp
psScavenge.cpp fprofiler.hpp
psScavenge.cpp gcCause.hpp
psScavenge.cpp gcLocker.inline.hpp
psScavenge.cpp gcTaskManager.hpp
+psScavenge.cpp generationSizer.hpp
psScavenge.cpp handles.inline.hpp
psScavenge.cpp isGCActiveMark.hpp
psScavenge.cpp oop.inline.hpp
--- a/hotspot/src/share/vm/gc_implementation/includeDB_gc_serial Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/includeDB_gc_serial Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
//
-// Copyright (c) 2007 Sun Microsystems, Inc. All Rights Reserved.
+// Copyright 2007-2010 Sun Microsystems, Inc. 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
@@ -29,6 +29,7 @@
adaptiveSizePolicy.hpp universe.hpp
adaptiveSizePolicy.cpp adaptiveSizePolicy.hpp
+adaptiveSizePolicy.cpp collectorPolicy.hpp
adaptiveSizePolicy.cpp gcCause.hpp
adaptiveSizePolicy.cpp ostream.hpp
adaptiveSizePolicy.cpp timer.hpp
--- a/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -892,6 +892,10 @@
}
swap_spaces();
+ // A successful scavenge should restart the GC time limit count which is
+ // for full GC's.
+ size_policy->reset_gc_overhead_limit_count();
+
assert(to()->is_empty(), "to space should be empty now");
} else {
assert(HandlePromotionFailure,
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -54,15 +54,16 @@
CollectedHeap::pre_initialize();
// Cannot be initialized until after the flags are parsed
- GenerationSizer flag_parser;
+ // GenerationSizer flag_parser;
+ _collector_policy = new GenerationSizer();
- size_t yg_min_size = flag_parser.min_young_gen_size();
- size_t yg_max_size = flag_parser.max_young_gen_size();
- size_t og_min_size = flag_parser.min_old_gen_size();
- size_t og_max_size = flag_parser.max_old_gen_size();
+ size_t yg_min_size = _collector_policy->min_young_gen_size();
+ size_t yg_max_size = _collector_policy->max_young_gen_size();
+ size_t og_min_size = _collector_policy->min_old_gen_size();
+ size_t og_max_size = _collector_policy->max_old_gen_size();
// Why isn't there a min_perm_gen_size()?
- size_t pg_min_size = flag_parser.perm_gen_size();
- size_t pg_max_size = flag_parser.max_perm_gen_size();
+ size_t pg_min_size = _collector_policy->perm_gen_size();
+ size_t pg_max_size = _collector_policy->max_perm_gen_size();
trace_gen_sizes("ps heap raw",
pg_min_size, pg_max_size,
@@ -89,12 +90,14 @@
// move to the common code.
yg_min_size = align_size_up(yg_min_size, yg_align);
yg_max_size = align_size_up(yg_max_size, yg_align);
- size_t yg_cur_size = align_size_up(flag_parser.young_gen_size(), yg_align);
+ size_t yg_cur_size =
+ align_size_up(_collector_policy->young_gen_size(), yg_align);
yg_cur_size = MAX2(yg_cur_size, yg_min_size);
og_min_size = align_size_up(og_min_size, og_align);
og_max_size = align_size_up(og_max_size, og_align);
- size_t og_cur_size = align_size_up(flag_parser.old_gen_size(), og_align);
+ size_t og_cur_size =
+ align_size_up(_collector_policy->old_gen_size(), og_align);
og_cur_size = MAX2(og_cur_size, og_min_size);
pg_min_size = align_size_up(pg_min_size, pg_align);
@@ -355,6 +358,11 @@
assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
+ // In general gc_overhead_limit_was_exceeded should be false so
+ // set it so here and reset it to true only if the gc time
+ // limit is being exceeded as checked below.
+ *gc_overhead_limit_was_exceeded = false;
+
HeapWord* result = young_gen()->allocate(size, is_tlab);
uint loop_count = 0;
@@ -428,24 +436,6 @@
if (result == NULL) {
- // Exit the loop if if the gc time limit has been exceeded.
- // The allocation must have failed above (result must be NULL),
- // and the most recent collection must have exceeded the
- // gc time limit. Exit the loop so that an out-of-memory
- // will be thrown (returning a NULL will do that), but
- // clear gc_time_limit_exceeded so that the next collection
- // will succeeded if the applications decides to handle the
- // out-of-memory and tries to go on.
- *gc_overhead_limit_was_exceeded = size_policy()->gc_time_limit_exceeded();
- if (size_policy()->gc_time_limit_exceeded()) {
- size_policy()->set_gc_time_limit_exceeded(false);
- if (PrintGCDetails && Verbose) {
- gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
- "return NULL because gc_time_limit_exceeded is set");
- }
- return NULL;
- }
-
// Generate a VM operation
VM_ParallelGCFailedAllocation op(size, is_tlab, gc_count);
VMThread::execute(&op);
@@ -463,16 +453,34 @@
assert(op.result() == NULL, "must be NULL if gc_locked() is true");
continue; // retry and/or stall as necessary
}
- // If a NULL result is being returned, an out-of-memory
- // will be thrown now. Clear the gc_time_limit_exceeded
- // flag to avoid the following situation.
- // gc_time_limit_exceeded is set during a collection
- // the collection fails to return enough space and an OOM is thrown
- // the next GC is skipped because the gc_time_limit_exceeded
- // flag is set and another OOM is thrown
- if (op.result() == NULL) {
- size_policy()->set_gc_time_limit_exceeded(false);
+
+ // Exit the loop if the gc time limit has been exceeded.
+ // The allocation must have failed above ("result" guarding
+ // this path is NULL) and the most recent collection has exceeded the
+ // gc overhead limit (although enough may have been collected to
+ // satisfy the allocation). Exit the loop so that an out-of-memory
+ // will be thrown (return a NULL ignoring the contents of
+ // op.result()),
+ // but clear gc_overhead_limit_exceeded so that the next collection
+ // starts with a clean slate (i.e., forgets about previous overhead
+ // excesses). Fill op.result() with a filler object so that the
+ // heap remains parsable.
+ const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
+ const bool softrefs_clear = collector_policy()->all_soft_refs_clear();
+ assert(!limit_exceeded || softrefs_clear, "Should have been cleared");
+ if (limit_exceeded && softrefs_clear) {
+ *gc_overhead_limit_was_exceeded = true;
+ size_policy()->set_gc_overhead_limit_exceeded(false);
+ if (PrintGCDetails && Verbose) {
+ gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
+ "return NULL because gc_overhead_limit_exceeded is set");
+ }
+ if (op.result() != NULL) {
+ CollectedHeap::fill_with_object(op.result(), size);
+ }
+ return NULL;
}
+
return op.result();
}
}
@@ -613,14 +621,15 @@
// and the most recent collection must have exceeded the
// gc time limit. Exit the loop so that an out-of-memory
// will be thrown (returning a NULL will do that), but
- // clear gc_time_limit_exceeded so that the next collection
+ // clear gc_overhead_limit_exceeded so that the next collection
// will succeeded if the applications decides to handle the
// out-of-memory and tries to go on.
- if (size_policy()->gc_time_limit_exceeded()) {
- size_policy()->set_gc_time_limit_exceeded(false);
+ const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
+ if (limit_exceeded) {
+ size_policy()->set_gc_overhead_limit_exceeded(false);
if (PrintGCDetails && Verbose) {
- gclog_or_tty->print_cr("ParallelScavengeHeap::permanent_mem_allocate: "
- "return NULL because gc_time_limit_exceeded is set");
+ gclog_or_tty->print_cr("ParallelScavengeHeap::permanent_mem_allocate:"
+ " return NULL because gc_overhead_limit_exceeded is set");
}
assert(result == NULL, "Allocation did not fail");
return NULL;
@@ -643,14 +652,15 @@
continue; // retry and/or stall as necessary
}
// If a NULL results is being returned, an out-of-memory
- // will be thrown now. Clear the gc_time_limit_exceeded
+ // will be thrown now. Clear the gc_overhead_limit_exceeded
// flag to avoid the following situation.
- // gc_time_limit_exceeded is set during a collection
+ // gc_overhead_limit_exceeded is set during a collection
// the collection fails to return enough space and an OOM is thrown
- // the next GC is skipped because the gc_time_limit_exceeded
- // flag is set and another OOM is thrown
+ // a subsequent GC prematurely throws an out-of-memory because
+ // the gc_overhead_limit_exceeded counts did not start
+ // again from 0.
if (op.result() == NULL) {
- size_policy()->set_gc_time_limit_exceeded(false);
+ size_policy()->reset_gc_overhead_limit_count();
}
return op.result();
}
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -25,6 +25,8 @@
class AdjoiningGenerations;
class GCTaskManager;
class PSAdaptiveSizePolicy;
+class GenerationSizer;
+class CollectorPolicy;
class ParallelScavengeHeap : public CollectedHeap {
friend class VMStructs;
@@ -43,6 +45,8 @@
size_t _young_gen_alignment;
size_t _old_gen_alignment;
+ GenerationSizer* _collector_policy;
+
inline size_t set_alignment(size_t& var, size_t val);
// Collection of generations that are adjacent in the
@@ -72,6 +76,9 @@
return CollectedHeap::ParallelScavengeHeap;
}
+CollectorPolicy* collector_policy() const { return (CollectorPolicy*) _collector_policy; }
+ // GenerationSizer* collector_policy() const { return _collector_policy; }
+
static PSYoungGen* young_gen() { return _young_gen; }
static PSOldGen* old_gen() { return _old_gen; }
static PSPermGen* perm_gen() { return _perm_gen; }
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2002-2007 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc. 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
@@ -184,18 +184,19 @@
set_change_young_gen_for_maj_pauses(0);
}
-
// If this is not a full GC, only test and modify the young generation.
-void PSAdaptiveSizePolicy::compute_generation_free_space(size_t young_live,
- size_t eden_live,
- size_t old_live,
- size_t perm_live,
- size_t cur_eden,
- size_t max_old_gen_size,
- size_t max_eden_size,
- bool is_full_gc,
- GCCause::Cause gc_cause) {
+void PSAdaptiveSizePolicy::compute_generation_free_space(
+ size_t young_live,
+ size_t eden_live,
+ size_t old_live,
+ size_t perm_live,
+ size_t cur_eden,
+ size_t max_old_gen_size,
+ size_t max_eden_size,
+ bool is_full_gc,
+ GCCause::Cause gc_cause,
+ CollectorPolicy* collector_policy) {
// Update statistics
// Time statistics are updated as we go, update footprint stats here
@@ -380,91 +381,16 @@
// Is too much time being spent in GC?
// Is the heap trying to grow beyond it's limits?
- const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
+ const size_t free_in_old_gen =
+ (size_t)(max_old_gen_size - avg_old_live()->average());
if (desired_promo_size > free_in_old_gen && desired_eden_size > eden_limit) {
-
- // eden_limit is the upper limit on the size of eden based on
- // the maximum size of the young generation and the sizes
- // of the survivor space.
- // The question being asked is whether the gc costs are high
- // and the space being recovered by a collection is low.
- // free_in_young_gen is the free space in the young generation
- // after a collection and promo_live is the free space in the old
- // generation after a collection.
- //
- // Use the minimum of the current value of the live in the
- // young gen or the average of the live in the young gen.
- // If the current value drops quickly, that should be taken
- // into account (i.e., don't trigger if the amount of free
- // space has suddenly jumped up). If the current is much
- // higher than the average, use the average since it represents
- // the longer term behavor.
- const size_t live_in_eden = MIN2(eden_live, (size_t) avg_eden_live()->average());
- const size_t free_in_eden = eden_limit > live_in_eden ?
- eden_limit - live_in_eden : 0;
- const size_t total_free_limit = free_in_old_gen + free_in_eden;
- const size_t total_mem = max_old_gen_size + max_eden_size;
- const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0);
- if (PrintAdaptiveSizePolicy && (Verbose ||
- (total_free_limit < (size_t) mem_free_limit))) {
- gclog_or_tty->print_cr(
- "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
- " promo_limit: " SIZE_FORMAT
- " eden_limit: " SIZE_FORMAT
- " total_free_limit: " SIZE_FORMAT
- " max_old_gen_size: " SIZE_FORMAT
- " max_eden_size: " SIZE_FORMAT
- " mem_free_limit: " SIZE_FORMAT,
- promo_limit, eden_limit, total_free_limit,
- max_old_gen_size, max_eden_size,
- (size_t) mem_free_limit);
- }
-
- if (is_full_gc) {
- if (gc_cost() > gc_cost_limit &&
- total_free_limit < (size_t) mem_free_limit) {
- // Collections, on average, are taking too much time, and
- // gc_cost() > gc_cost_limit
- // we have too little space available after a full gc.
- // total_free_limit < mem_free_limit
- // where
- // total_free_limit is the free space available in
- // both generations
- // total_mem is the total space available for allocation
- // in both generations (survivor spaces are not included
- // just as they are not included in eden_limit).
- // mem_free_limit is a fraction of total_mem judged to be an
- // acceptable amount that is still unused.
- // The heap can ask for the value of this variable when deciding
- // whether to thrown an OutOfMemory error.
- // Note that the gc time limit test only works for the collections
- // of the young gen + tenured gen and not for collections of the
- // permanent gen. That is because the calculation of the space
- // freed by the collection is the free space in the young gen +
- // tenured gen.
- // Ignore explicit GC's. Ignoring explicit GC's at this level
- // is the equivalent of the GC did not happen as far as the
- // overhead calculation is concerted (i.e., the flag is not set
- // and the count is not affected). Also the average will not
- // have been updated unless UseAdaptiveSizePolicyWithSystemGC is on.
- if (!GCCause::is_user_requested_gc(gc_cause) &&
- !GCCause::is_serviceability_requested_gc(gc_cause)) {
- inc_gc_time_limit_count();
- if (UseGCOverheadLimit &&
- (gc_time_limit_count() > AdaptiveSizePolicyGCTimeLimitThreshold)){
- // All conditions have been met for throwing an out-of-memory
- _gc_time_limit_exceeded = true;
- // Avoid consecutive OOM due to the gc time limit by resetting
- // the counter.
- reset_gc_time_limit_count();
- }
- _print_gc_time_limit_would_be_exceeded = true;
- }
- } else {
- // Did not exceed overhead limits
- reset_gc_time_limit_count();
- }
- }
+ check_gc_overhead_limit(young_live,
+ eden_live,
+ max_old_gen_size,
+ max_eden_size,
+ is_full_gc,
+ gc_cause,
+ collector_policy);
}
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2002-2007 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc. 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
@@ -45,6 +45,7 @@
// Forward decls
class elapsedTimer;
+class GenerationSizer;
class PSAdaptiveSizePolicy : public AdaptiveSizePolicy {
friend class PSGCAdaptivePolicyCounters;
@@ -340,7 +341,8 @@
size_t max_old_gen_size,
size_t max_eden_size,
bool is_full_gc,
- GCCause::Cause gc_cause);
+ GCCause::Cause gc_cause,
+ CollectorPolicy* collector_policy);
// Calculates new survivor space size; returns a new tenuring threshold
// value. Stores new survivor size in _survivor_size.
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2003-2010 Sun Microsystems, Inc. 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
@@ -117,11 +117,13 @@
PerfData::U_Bytes, (jlong) ps_size_policy()->avg_base_footprint()->average(), CHECK);
cname = PerfDataManager::counter_name(name_space(), "gcTimeLimitExceeded");
- _gc_time_limit_exceeded = PerfDataManager::create_variable(SUN_GC, cname,
- PerfData::U_Events, ps_size_policy()->gc_time_limit_exceeded(), CHECK);
+ _gc_overhead_limit_exceeded_counter =
+ PerfDataManager::create_variable(SUN_GC, cname,
+ PerfData::U_Events, ps_size_policy()->gc_overhead_limit_exceeded(), CHECK);
cname = PerfDataManager::counter_name(name_space(), "liveAtLastFullGc");
- _live_at_last_full_gc = PerfDataManager::create_variable(SUN_GC, cname,
+ _live_at_last_full_gc_counter =
+ PerfDataManager::create_variable(SUN_GC, cname,
PerfData::U_Bytes, ps_size_policy()->live_at_last_full_gc(), CHECK);
cname = PerfDataManager::counter_name(name_space(), "majorPauseOldSlope");
@@ -189,6 +191,8 @@
update_minor_pause_old_slope();
update_major_pause_young_slope();
update_minor_collection_slope_counter();
+ update_gc_overhead_limit_exceeded_counter();
+ update_live_at_last_full_gc_counter();
}
}
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2003-2005 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2003-2010 Sun Microsystems, Inc. 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
@@ -44,8 +44,8 @@
PerfVariable* _live_space;
PerfVariable* _free_space;
PerfVariable* _avg_base_footprint;
- PerfVariable* _gc_time_limit_exceeded;
- PerfVariable* _live_at_last_full_gc;
+ PerfVariable* _gc_overhead_limit_exceeded_counter;
+ PerfVariable* _live_at_last_full_gc_counter;
PerfVariable* _old_capacity;
PerfVariable* _boundary_moved;
@@ -169,6 +169,14 @@
(jlong)(ps_size_policy()->major_pause_young_slope() * 1000)
);
}
+ inline void update_gc_overhead_limit_exceeded_counter() {
+ _gc_overhead_limit_exceeded_counter->set_value(
+ (jlong) ps_size_policy()->gc_overhead_limit_exceeded());
+ }
+ inline void update_live_at_last_full_gc_counter() {
+ _live_at_last_full_gc_counter->set_value(
+ (jlong)(ps_size_policy()->live_at_last_full_gc()));
+ }
inline void update_scavenge_skipped(int cause) {
_scavenge_skipped->set_value(cause);
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -46,6 +46,12 @@
//
// Note that this method should only be called from the vm_thread while
// at a safepoint!
+//
+// Note that the all_soft_refs_clear flag in the collector policy
+// may be true because this method can be called without intervening
+// activity. For example when the heap space is tight and full measure
+// are being taken to free space.
+
void PSMarkSweep::invoke(bool maximum_heap_compaction) {
assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
@@ -54,24 +60,18 @@
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
GCCause::Cause gc_cause = heap->gc_cause();
PSAdaptiveSizePolicy* policy = heap->size_policy();
+ IsGCActiveMark mark;
- // Before each allocation/collection attempt, find out from the
- // policy object if GCs are, on the whole, taking too long. If so,
- // bail out without attempting a collection. The exceptions are
- // for explicitly requested GC's.
- if (!policy->gc_time_limit_exceeded() ||
- GCCause::is_user_requested_gc(gc_cause) ||
- GCCause::is_serviceability_requested_gc(gc_cause)) {
- IsGCActiveMark mark;
+ if (ScavengeBeforeFullGC) {
+ PSScavenge::invoke_no_policy();
+ }
- if (ScavengeBeforeFullGC) {
- PSScavenge::invoke_no_policy();
- }
+ const bool clear_all_soft_refs =
+ heap->collector_policy()->should_clear_all_soft_refs();
- int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount;
- IntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
- PSMarkSweep::invoke_no_policy(maximum_heap_compaction);
- }
+ int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount;
+ IntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
+ PSMarkSweep::invoke_no_policy(clear_all_soft_refs || maximum_heap_compaction);
}
// This method contains no policy. You should probably
@@ -89,6 +89,10 @@
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
PSAdaptiveSizePolicy* size_policy = heap->size_policy();
+ // The scope of casr should end after code that can change
+ // CollectorPolicy::_should_clear_all_soft_refs.
+ ClearedAllSoftRefs casr(clear_all_softrefs, heap->collector_policy());
+
PSYoungGen* young_gen = heap->young_gen();
PSOldGen* old_gen = heap->old_gen();
PSPermGen* perm_gen = heap->perm_gen();
@@ -275,7 +279,8 @@
old_gen->max_gen_size(),
max_eden_size,
true /* full gc*/,
- gc_cause);
+ gc_cause,
+ heap->collector_policy());
heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
@@ -326,19 +331,6 @@
// Track memory usage and detect low memory
MemoryService::track_memory_usage();
heap->update_counters();
-
- if (PrintGCDetails) {
- if (size_policy->print_gc_time_limit_would_be_exceeded()) {
- if (size_policy->gc_time_limit_exceeded()) {
- gclog_or_tty->print_cr(" GC time is exceeding GCTimeLimit "
- "of %d%%", GCTimeLimit);
- } else {
- gclog_or_tty->print_cr(" GC time would exceed GCTimeLimit "
- "of %d%%", GCTimeLimit);
- }
- }
- size_policy->set_print_gc_time_limit_would_be_exceeded(false);
- }
}
if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2005-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2005-2010 Sun Microsystems, Inc. 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
@@ -1923,31 +1923,32 @@
//
// Note that this method should only be called from the vm_thread while at a
// safepoint.
+//
+// Note that the all_soft_refs_clear flag in the collector policy
+// may be true because this method can be called without intervening
+// activity. For example when the heap space is tight and full measure
+// are being taken to free space.
void PSParallelCompact::invoke(bool maximum_heap_compaction) {
assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
assert(Thread::current() == (Thread*)VMThread::vm_thread(),
"should be in vm thread");
+
ParallelScavengeHeap* heap = gc_heap();
GCCause::Cause gc_cause = heap->gc_cause();
assert(!heap->is_gc_active(), "not reentrant");
PSAdaptiveSizePolicy* policy = heap->size_policy();
-
- // Before each allocation/collection attempt, find out from the
- // policy object if GCs are, on the whole, taking too long. If so,
- // bail out without attempting a collection. The exceptions are
- // for explicitly requested GC's.
- if (!policy->gc_time_limit_exceeded() ||
- GCCause::is_user_requested_gc(gc_cause) ||
- GCCause::is_serviceability_requested_gc(gc_cause)) {
- IsGCActiveMark mark;
-
- if (ScavengeBeforeFullGC) {
- PSScavenge::invoke_no_policy();
- }
-
- PSParallelCompact::invoke_no_policy(maximum_heap_compaction);
+ IsGCActiveMark mark;
+
+ if (ScavengeBeforeFullGC) {
+ PSScavenge::invoke_no_policy();
}
+
+ const bool clear_all_soft_refs =
+ heap->collector_policy()->should_clear_all_soft_refs();
+
+ PSParallelCompact::invoke_no_policy(clear_all_soft_refs ||
+ maximum_heap_compaction);
}
bool ParallelCompactData::region_contains(size_t region_index, HeapWord* addr) {
@@ -1976,6 +1977,11 @@
PSPermGen* perm_gen = heap->perm_gen();
PSAdaptiveSizePolicy* size_policy = heap->size_policy();
+ // The scope of casr should end after code that can change
+ // CollectorPolicy::_should_clear_all_soft_refs.
+ ClearedAllSoftRefs casr(maximum_heap_compaction,
+ heap->collector_policy());
+
if (ZapUnusedHeapArea) {
// Save information needed to minimize mangling
heap->record_gen_tops_before_GC();
@@ -2109,7 +2115,8 @@
old_gen->max_gen_size(),
max_eden_size,
true /* full gc*/,
- gc_cause);
+ gc_cause,
+ heap->collector_policy());
heap->resize_old_gen(
size_policy->calculated_old_free_size_in_bytes());
@@ -2157,19 +2164,6 @@
// Track memory usage and detect low memory
MemoryService::track_memory_usage();
heap->update_counters();
-
- if (PrintGCDetails) {
- if (size_policy->print_gc_time_limit_would_be_exceeded()) {
- if (size_policy->gc_time_limit_exceeded()) {
- gclog_or_tty->print_cr(" GC time is exceeding GCTimeLimit "
- "of %d%%", GCTimeLimit);
- } else {
- gclog_or_tty->print_cr(" GC time would exceed GCTimeLimit "
- "of %d%%", GCTimeLimit);
- }
- }
- size_policy->set_print_gc_time_limit_would_be_exceeded(false);
- }
}
if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2002-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc. 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
@@ -187,8 +187,7 @@
//
// Note that this method should only be called from the vm_thread while
// at a safepoint!
-void PSScavenge::invoke()
-{
+void PSScavenge::invoke() {
assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
assert(!Universe::heap()->is_gc_active(), "not reentrant");
@@ -197,29 +196,25 @@
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
PSAdaptiveSizePolicy* policy = heap->size_policy();
+ IsGCActiveMark mark;
- // Before each allocation/collection attempt, find out from the
- // policy object if GCs are, on the whole, taking too long. If so,
- // bail out without attempting a collection.
- if (!policy->gc_time_limit_exceeded()) {
- IsGCActiveMark mark;
+ bool scavenge_was_done = PSScavenge::invoke_no_policy();
- bool scavenge_was_done = PSScavenge::invoke_no_policy();
-
- PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
+ PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
+ if (UsePerfData)
+ counters->update_full_follows_scavenge(0);
+ if (!scavenge_was_done ||
+ policy->should_full_GC(heap->old_gen()->free_in_bytes())) {
if (UsePerfData)
- counters->update_full_follows_scavenge(0);
- if (!scavenge_was_done ||
- policy->should_full_GC(heap->old_gen()->free_in_bytes())) {
- if (UsePerfData)
- counters->update_full_follows_scavenge(full_follows_scavenge);
+ counters->update_full_follows_scavenge(full_follows_scavenge);
+ GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy);
+ CollectorPolicy* cp = heap->collector_policy();
+ const bool clear_all_softrefs = cp->should_clear_all_soft_refs();
- GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy);
- if (UseParallelOldGC) {
- PSParallelCompact::invoke_no_policy(false);
- } else {
- PSMarkSweep::invoke_no_policy(false);
- }
+ if (UseParallelOldGC) {
+ PSParallelCompact::invoke_no_policy(clear_all_softrefs);
+ } else {
+ PSMarkSweep::invoke_no_policy(clear_all_softrefs);
}
}
}
@@ -447,6 +442,9 @@
size_t promoted = old_gen->used_in_bytes() - old_gen_used_before;
size_policy->update_averages(_survivor_overflow, survived, promoted);
+ // A successful scavenge should restart the GC time limit count which is
+ // for full GC's.
+ size_policy->reset_gc_overhead_limit_count();
if (UseAdaptiveSizePolicy) {
// Calculate the new survivor size and tenuring threshold
@@ -523,7 +521,8 @@
old_gen->max_gen_size(),
max_eden_size,
false /* full gc*/,
- gc_cause);
+ gc_cause,
+ heap->collector_policy());
}
// Resize the young generation at every collection
--- a/hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2004-2006 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2004-2010 Sun Microsystems, Inc. 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
@@ -44,13 +44,15 @@
_survivor_size(init_survivor_size),
_gc_pause_goal_sec(gc_pause_goal_sec),
_throughput_goal(1.0 - double(1.0 / (1.0 + (double) gc_cost_ratio))),
- _gc_time_limit_exceeded(false),
- _print_gc_time_limit_would_be_exceeded(false),
- _gc_time_limit_count(0),
+ _gc_overhead_limit_exceeded(false),
+ _print_gc_overhead_limit_would_be_exceeded(false),
+ _gc_overhead_limit_count(0),
_latest_minor_mutator_interval_seconds(0),
_threshold_tolerance_percent(1.0 + ThresholdTolerance/100.0),
_young_gen_change_for_minor_throughput(0),
_old_gen_change_for_major_throughput(0) {
+ assert(AdaptiveSizePolicyGCTimeLimitThreshold > 0,
+ "No opportunity to clear SoftReferences before GC overhead limit");
_avg_minor_pause =
new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding);
_avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
@@ -278,6 +280,147 @@
set_decide_at_full_gc(0);
}
+void AdaptiveSizePolicy::check_gc_overhead_limit(
+ size_t young_live,
+ size_t eden_live,
+ size_t max_old_gen_size,
+ size_t max_eden_size,
+ bool is_full_gc,
+ GCCause::Cause gc_cause,
+ CollectorPolicy* collector_policy) {
+
+ // Ignore explicit GC's. Exiting here does not set the flag and
+ // does not reset the count. Updating of the averages for system
+ // GC's is still controlled by UseAdaptiveSizePolicyWithSystemGC.
+ if (GCCause::is_user_requested_gc(gc_cause) ||
+ GCCause::is_serviceability_requested_gc(gc_cause)) {
+ return;
+ }
+ // eden_limit is the upper limit on the size of eden based on
+ // the maximum size of the young generation and the sizes
+ // of the survivor space.
+ // The question being asked is whether the gc costs are high
+ // and the space being recovered by a collection is low.
+ // free_in_young_gen is the free space in the young generation
+ // after a collection and promo_live is the free space in the old
+ // generation after a collection.
+ //
+ // Use the minimum of the current value of the live in the
+ // young gen or the average of the live in the young gen.
+ // If the current value drops quickly, that should be taken
+ // into account (i.e., don't trigger if the amount of free
+ // space has suddenly jumped up). If the current is much
+ // higher than the average, use the average since it represents
+ // the longer term behavor.
+ const size_t live_in_eden =
+ MIN2(eden_live, (size_t) avg_eden_live()->average());
+ const size_t free_in_eden = max_eden_size > live_in_eden ?
+ max_eden_size - live_in_eden : 0;
+ const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
+ const size_t total_free_limit = free_in_old_gen + free_in_eden;
+ const size_t total_mem = max_old_gen_size + max_eden_size;
+ const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0);
+ const double mem_free_old_limit = max_old_gen_size * (GCHeapFreeLimit/100.0);
+ const double mem_free_eden_limit = max_eden_size * (GCHeapFreeLimit/100.0);
+ const double gc_cost_limit = GCTimeLimit/100.0;
+ size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average());
+ // But don't force a promo size below the current promo size. Otherwise,
+ // the promo size will shrink for no good reason.
+ promo_limit = MAX2(promo_limit, _promo_size);
+
+
+ if (PrintAdaptiveSizePolicy && (Verbose ||
+ (free_in_old_gen < (size_t) mem_free_old_limit &&
+ free_in_eden < (size_t) mem_free_eden_limit))) {
+ gclog_or_tty->print_cr(
+ "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
+ " promo_limit: " SIZE_FORMAT
+ " max_eden_size: " SIZE_FORMAT
+ " total_free_limit: " SIZE_FORMAT
+ " max_old_gen_size: " SIZE_FORMAT
+ " max_eden_size: " SIZE_FORMAT
+ " mem_free_limit: " SIZE_FORMAT,
+ promo_limit, max_eden_size, total_free_limit,
+ max_old_gen_size, max_eden_size,
+ (size_t) mem_free_limit);
+ }
+
+ bool print_gc_overhead_limit_would_be_exceeded = false;
+ if (is_full_gc) {
+ if (gc_cost() > gc_cost_limit &&
+ free_in_old_gen < (size_t) mem_free_old_limit &&
+ free_in_eden < (size_t) mem_free_eden_limit) {
+ // Collections, on average, are taking too much time, and
+ // gc_cost() > gc_cost_limit
+ // we have too little space available after a full gc.
+ // total_free_limit < mem_free_limit
+ // where
+ // total_free_limit is the free space available in
+ // both generations
+ // total_mem is the total space available for allocation
+ // in both generations (survivor spaces are not included
+ // just as they are not included in eden_limit).
+ // mem_free_limit is a fraction of total_mem judged to be an
+ // acceptable amount that is still unused.
+ // The heap can ask for the value of this variable when deciding
+ // whether to thrown an OutOfMemory error.
+ // Note that the gc time limit test only works for the collections
+ // of the young gen + tenured gen and not for collections of the
+ // permanent gen. That is because the calculation of the space
+ // freed by the collection is the free space in the young gen +
+ // tenured gen.
+ // At this point the GC overhead limit is being exceeded.
+ inc_gc_overhead_limit_count();
+ if (UseGCOverheadLimit) {
+ if (gc_overhead_limit_count() >=
+ AdaptiveSizePolicyGCTimeLimitThreshold){
+ // All conditions have been met for throwing an out-of-memory
+ set_gc_overhead_limit_exceeded(true);
+ // Avoid consecutive OOM due to the gc time limit by resetting
+ // the counter.
+ reset_gc_overhead_limit_count();
+ } else {
+ // The required consecutive collections which exceed the
+ // GC time limit may or may not have been reached. We
+ // are approaching that condition and so as not to
+ // throw an out-of-memory before all SoftRef's have been
+ // cleared, set _should_clear_all_soft_refs in CollectorPolicy.
+ // The clearing will be done on the next GC.
+ bool near_limit = gc_overhead_limit_near();
+ if (near_limit) {
+ collector_policy->set_should_clear_all_soft_refs(true);
+ if (PrintGCDetails && Verbose) {
+ gclog_or_tty->print_cr(" Nearing GC overhead limit, "
+ "will be clearing all SoftReference");
+ }
+ }
+ }
+ }
+ // Set this even when the overhead limit will not
+ // cause an out-of-memory. Diagnostic message indicating
+ // that the overhead limit is being exceeded is sometimes
+ // printed.
+ print_gc_overhead_limit_would_be_exceeded = true;
+
+ } else {
+ // Did not exceed overhead limits
+ reset_gc_overhead_limit_count();
+ }
+ }
+
+ if (UseGCOverheadLimit && PrintGCDetails && Verbose) {
+ if (gc_overhead_limit_exceeded()) {
+ gclog_or_tty->print_cr(" GC is exceeding overhead limit "
+ "of %d%%", GCTimeLimit);
+ reset_gc_overhead_limit_count();
+ } else if (print_gc_overhead_limit_would_be_exceeded) {
+ assert(gc_overhead_limit_count() > 0, "Should not be printing");
+ gclog_or_tty->print_cr(" GC would exceed overhead limit "
+ "of %d%% %d consecutive time(s)",
+ GCTimeLimit, gc_overhead_limit_count());
+ }
+ }
+}
// Printing
bool AdaptiveSizePolicy::print_adaptive_size_policy_on(outputStream* st) const {
--- a/hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2004-2006 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2004-2010 Sun Microsystems, Inc. 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
@@ -27,6 +27,7 @@
// Forward decls
class elapsedTimer;
+class CollectorPolicy;
class AdaptiveSizePolicy : public CHeapObj {
friend class GCAdaptivePolicyCounters;
@@ -75,13 +76,16 @@
// This is a hint for the heap: we've detected that gc times
// are taking longer than GCTimeLimit allows.
- bool _gc_time_limit_exceeded;
- // Use for diagnostics only. If UseGCTimeLimit is false,
+ bool _gc_overhead_limit_exceeded;
+ // Use for diagnostics only. If UseGCOverheadLimit is false,
// this variable is still set.
- bool _print_gc_time_limit_would_be_exceeded;
+ bool _print_gc_overhead_limit_would_be_exceeded;
// Count of consecutive GC that have exceeded the
// GC time limit criterion.
- uint _gc_time_limit_count;
+ uint _gc_overhead_limit_count;
+ // This flag signals that GCTimeLimit is being exceeded
+ // but may not have done so for the required number of consequetive
+ // collections.
// Minor collection timers used to determine both
// pause and interval times for collections.
@@ -406,22 +410,21 @@
// Most heaps will choose to throw an OutOfMemoryError when
// this occurs but it is up to the heap to request this information
// of the policy
- bool gc_time_limit_exceeded() {
- return _gc_time_limit_exceeded;
- }
- void set_gc_time_limit_exceeded(bool v) {
- _gc_time_limit_exceeded = v;
+ bool gc_overhead_limit_exceeded() {
+ return _gc_overhead_limit_exceeded;
}
- bool print_gc_time_limit_would_be_exceeded() {
- return _print_gc_time_limit_would_be_exceeded;
- }
- void set_print_gc_time_limit_would_be_exceeded(bool v) {
- _print_gc_time_limit_would_be_exceeded = v;
+ void set_gc_overhead_limit_exceeded(bool v) {
+ _gc_overhead_limit_exceeded = v;
}
- uint gc_time_limit_count() { return _gc_time_limit_count; }
- void reset_gc_time_limit_count() { _gc_time_limit_count = 0; }
- void inc_gc_time_limit_count() { _gc_time_limit_count++; }
+ // Tests conditions indicate the GC overhead limit is being approached.
+ bool gc_overhead_limit_near() {
+ return gc_overhead_limit_count() >=
+ (AdaptiveSizePolicyGCTimeLimitThreshold - 1);
+ }
+ uint gc_overhead_limit_count() { return _gc_overhead_limit_count; }
+ void reset_gc_overhead_limit_count() { _gc_overhead_limit_count = 0; }
+ void inc_gc_overhead_limit_count() { _gc_overhead_limit_count++; }
// accessors for flags recording the decisions to resize the
// generations to meet the pause goal.
@@ -436,6 +439,16 @@
int decide_at_full_gc() { return _decide_at_full_gc; }
void set_decide_at_full_gc(int v) { _decide_at_full_gc = v; }
+ // Check the conditions for an out-of-memory due to excessive GC time.
+ // Set _gc_overhead_limit_exceeded if all the conditions have been met.
+ void check_gc_overhead_limit(size_t young_live,
+ size_t eden_live,
+ size_t max_old_gen_size,
+ size_t max_eden_size,
+ bool is_full_gc,
+ GCCause::Cause gc_cause,
+ CollectorPolicy* collector_policy);
+
// Printing support
virtual bool print_adaptive_size_policy_on(outputStream* st) const;
bool print_adaptive_size_policy_on(outputStream* st, int
--- a/hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -115,11 +115,25 @@
void VM_GC_HeapInspection::doit() {
HandleMark hm;
CollectedHeap* ch = Universe::heap();
+ ch->ensure_parsability(false); // must happen, even if collection does
+ // not happen (e.g. due to GC_locker)
if (_full_gc) {
- ch->collect_as_vm_thread(GCCause::_heap_inspection);
- } else {
- // make the heap parsable (no need to retire TLABs)
- ch->ensure_parsability(false);
+ // The collection attempt below would be skipped anyway if
+ // the gc locker is held. The following dump may then be a tad
+ // misleading to someone expecting only live objects to show
+ // up in the dump (see CR 6944195). Just issue a suitable warning
+ // in that case and do not attempt to do a collection.
+ // The latter is a subtle point, because even a failed attempt
+ // to GC will, in fact, induce one in the future, which we
+ // probably want to avoid in this case because the GC that we may
+ // be about to attempt holds value for us only
+ // if it happens now and not if it happens in the eventual
+ // future.
+ if (GC_locker::is_active()) {
+ warning("GC locker is held; pre-dump GC was skipped");
+ } else {
+ ch->collect_as_vm_thread(GCCause::_heap_inspection);
+ }
}
HeapInspection::heap_inspection(_out, _need_prologue /* need_prologue */);
}
--- a/hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2005-2008 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2005-2010 Sun Microsystems, Inc. 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
@@ -89,8 +89,19 @@
if (full) {
_full_gc_count_before = full_gc_count_before;
}
+ // In ParallelScavengeHeap::mem_allocate() collections can be
+ // executed within a loop and _all_soft_refs_clear can be set
+ // true after they have been cleared by a collection and another
+ // collection started so that _all_soft_refs_clear can be true
+ // when this collection is started. Don't assert that
+ // _all_soft_refs_clear have to be false here even though
+ // mutators have run. Soft refs will be cleared again in this
+ // collection.
}
- ~VM_GC_Operation() {}
+ ~VM_GC_Operation() {
+ CollectedHeap* ch = Universe::heap();
+ ch->collector_policy()->set_all_soft_refs_clear(false);
+ }
// Acquire the reference synchronization lock
virtual bool doit_prologue();
--- a/hotspot/src/share/vm/gc_interface/collectedHeap.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/gc_interface/collectedHeap.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -31,6 +31,7 @@
class ThreadClosure;
class AdaptiveSizePolicy;
class Thread;
+class CollectorPolicy;
//
// CollectedHeap
@@ -506,6 +507,9 @@
// Return the AdaptiveSizePolicy for the heap.
virtual AdaptiveSizePolicy* size_policy() = 0;
+ // Return the CollectorPolicy for the heap
+ virtual CollectorPolicy* collector_policy() const = 0;
+
// Iterate over all the ref-containing fields of all objects, calling
// "cl.do_oop" on each. This includes objects in permanent memory.
virtual void oop_iterate(OopClosure* cl) = 0;
--- a/hotspot/src/share/vm/memory/collectorPolicy.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/memory/collectorPolicy.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2008 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -112,6 +112,11 @@
}
}
+bool CollectorPolicy::use_should_clear_all_soft_refs(bool v) {
+ bool result = _should_clear_all_soft_refs;
+ set_should_clear_all_soft_refs(false);
+ return result;
+}
GenRemSet* CollectorPolicy::create_rem_set(MemRegion whole_heap,
int max_covered_regions) {
@@ -126,6 +131,17 @@
}
}
+void CollectorPolicy::cleared_all_soft_refs() {
+ // If near gc overhear limit, continue to clear SoftRefs. SoftRefs may
+ // have been cleared in the last collection but if the gc overhear
+ // limit continues to be near, SoftRefs should still be cleared.
+ if (size_policy() != NULL) {
+ _should_clear_all_soft_refs = size_policy()->gc_overhead_limit_near();
+ }
+ _all_soft_refs_clear = true;
+}
+
+
// GenCollectorPolicy methods.
size_t GenCollectorPolicy::scale_by_NewRatio_aligned(size_t base_size) {
@@ -489,6 +505,12 @@
debug_only(gch->check_for_valid_allocation_state());
assert(gch->no_gc_in_progress(), "Allocation during gc not allowed");
+
+ // In general gc_overhead_limit_was_exceeded should be false so
+ // set it so here and reset it to true only if the gc time
+ // limit is being exceeded as checked below.
+ *gc_overhead_limit_was_exceeded = false;
+
HeapWord* result = NULL;
// Loop until the allocation is satisified,
@@ -524,12 +546,6 @@
return result;
}
- // There are NULL's returned for different circumstances below.
- // In general gc_overhead_limit_was_exceeded should be false so
- // set it so here and reset it to true only if the gc time
- // limit is being exceeded as checked below.
- *gc_overhead_limit_was_exceeded = false;
-
if (GC_locker::is_active_and_needs_gc()) {
if (is_tlab) {
return NULL; // Caller will retry allocating individual object
@@ -568,18 +584,6 @@
gc_count_before = Universe::heap()->total_collections();
}
- // Allocation has failed and a collection is about
- // to be done. If the gc time limit was exceeded the
- // last time a collection was done, return NULL so
- // that an out-of-memory will be thrown. Clear
- // gc_time_limit_exceeded so that subsequent attempts
- // at a collection will be made.
- if (size_policy()->gc_time_limit_exceeded()) {
- *gc_overhead_limit_was_exceeded = true;
- size_policy()->set_gc_time_limit_exceeded(false);
- return NULL;
- }
-
VM_GenCollectForAllocation op(size,
is_tlab,
gc_count_before);
@@ -590,6 +594,24 @@
assert(result == NULL, "must be NULL if gc_locked() is true");
continue; // retry and/or stall as necessary
}
+
+ // Allocation has failed and a collection
+ // has been done. If the gc time limit was exceeded the
+ // this time, return NULL so that an out-of-memory
+ // will be thrown. Clear gc_overhead_limit_exceeded
+ // so that the overhead exceeded does not persist.
+
+ const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
+ const bool softrefs_clear = all_soft_refs_clear();
+ assert(!limit_exceeded || softrefs_clear, "Should have been cleared");
+ if (limit_exceeded && softrefs_clear) {
+ *gc_overhead_limit_was_exceeded = true;
+ size_policy()->set_gc_overhead_limit_exceeded(false);
+ if (op.result() != NULL) {
+ CollectedHeap::fill_with_object(op.result(), size);
+ }
+ return NULL;
+ }
assert(result == NULL || gch->is_in_reserved(result),
"result not in heap");
return result;
@@ -688,6 +710,9 @@
return result;
}
+ assert(!should_clear_all_soft_refs(),
+ "Flag should have been handled and cleared prior to this point");
+
// What else? We might try synchronous finalization later. If the total
// space available is large enough for the allocation, then a more
// complete compaction phase than we've tried so far might be
--- a/hotspot/src/share/vm/memory/collectorPolicy.hpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/memory/collectorPolicy.hpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2008 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -69,12 +69,28 @@
size_t _min_alignment;
size_t _max_alignment;
+ // The sizing of the heap are controlled by a sizing policy.
+ AdaptiveSizePolicy* _size_policy;
+
+ // Set to true when policy wants soft refs cleared.
+ // Reset to false by gc after it clears all soft refs.
+ bool _should_clear_all_soft_refs;
+ // Set to true by the GC if the just-completed gc cleared all
+ // softrefs. This is set to true whenever a gc clears all softrefs, and
+ // set to false each time gc returns to the mutator. For example, in the
+ // ParallelScavengeHeap case the latter would be done toward the end of
+ // mem_allocate() where it returns op.result()
+ bool _all_soft_refs_clear;
+
CollectorPolicy() :
_min_alignment(1),
_max_alignment(1),
_initial_heap_byte_size(0),
_max_heap_byte_size(0),
- _min_heap_byte_size(0)
+ _min_heap_byte_size(0),
+ _size_policy(NULL),
+ _should_clear_all_soft_refs(false),
+ _all_soft_refs_clear(false)
{}
public:
@@ -98,6 +114,19 @@
G1CollectorPolicyKind
};
+ AdaptiveSizePolicy* size_policy() { return _size_policy; }
+ bool should_clear_all_soft_refs() { return _should_clear_all_soft_refs; }
+ void set_should_clear_all_soft_refs(bool v) { _should_clear_all_soft_refs = v; }
+ // Returns the current value of _should_clear_all_soft_refs.
+ // _should_clear_all_soft_refs is set to false as a side effect.
+ bool use_should_clear_all_soft_refs(bool v);
+ bool all_soft_refs_clear() { return _all_soft_refs_clear; }
+ void set_all_soft_refs_clear(bool v) { _all_soft_refs_clear = v; }
+
+ // Called by the GC after Soft Refs have been cleared to indicate
+ // that the request in _should_clear_all_soft_refs has been fulfilled.
+ void cleared_all_soft_refs();
+
// Identification methods.
virtual GenCollectorPolicy* as_generation_policy() { return NULL; }
virtual TwoGenerationCollectorPolicy* as_two_generation_policy() { return NULL; }
@@ -165,6 +194,22 @@
};
+class ClearedAllSoftRefs : public StackObj {
+ bool _clear_all_soft_refs;
+ CollectorPolicy* _collector_policy;
+ public:
+ ClearedAllSoftRefs(bool clear_all_soft_refs,
+ CollectorPolicy* collector_policy) :
+ _clear_all_soft_refs(clear_all_soft_refs),
+ _collector_policy(collector_policy) {}
+
+ ~ClearedAllSoftRefs() {
+ if (_clear_all_soft_refs) {
+ _collector_policy->cleared_all_soft_refs();
+ }
+ }
+};
+
class GenCollectorPolicy : public CollectorPolicy {
protected:
size_t _min_gen0_size;
@@ -173,10 +218,6 @@
GenerationSpec **_generations;
- // The sizing of the different generations in the heap are controlled
- // by a sizing policy.
- AdaptiveSizePolicy* _size_policy;
-
// Return true if an allocation should be attempted in the older
// generation if it fails in the younger generation. Return
// false, otherwise.
@@ -236,14 +277,11 @@
virtual size_t large_typearray_limit();
// Adaptive size policy
- AdaptiveSizePolicy* size_policy() { return _size_policy; }
virtual void initialize_size_policy(size_t init_eden_size,
size_t init_promo_size,
size_t init_survivor_size);
-
};
-
// All of hotspot's current collectors are subtypes of this
// class. Currently, these collectors all use the same gen[0],
// but have different gen[1] types. If we add another subtype
--- a/hotspot/src/share/vm/memory/defNewGeneration.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/memory/defNewGeneration.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2008 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -594,6 +594,10 @@
_tenuring_threshold =
age_table()->compute_tenuring_threshold(to()->capacity()/HeapWordSize);
+ // A successful scavenge should restart the GC time limit count which is
+ // for full GC's.
+ AdaptiveSizePolicy* size_policy = gch->gen_policy()->size_policy();
+ size_policy->reset_gc_overhead_limit_count();
if (PrintGC && !PrintGCDetails) {
gch->print_heap_change(gch_prev_used);
}
--- a/hotspot/src/share/vm/memory/genCollectedHeap.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/memory/genCollectedHeap.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2000-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2000-2010 Sun Microsystems, Inc. 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
@@ -428,7 +428,8 @@
assert(my_thread->is_VM_thread() ||
my_thread->is_ConcurrentGC_thread(),
"incorrect thread type capability");
- assert(Heap_lock->is_locked(), "the requesting thread should have the Heap_lock");
+ assert(Heap_lock->is_locked(),
+ "the requesting thread should have the Heap_lock");
guarantee(!is_gc_active(), "collection is not reentrant");
assert(max_level < n_gens(), "sanity check");
@@ -436,6 +437,11 @@
return; // GC is disabled (e.g. JNI GetXXXCritical operation)
}
+ const bool do_clear_all_soft_refs = clear_all_soft_refs ||
+ collector_policy()->should_clear_all_soft_refs();
+
+ ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
+
const size_t perm_prev_used = perm_gen()->used();
if (PrintHeapAtGC) {
@@ -560,11 +566,11 @@
if (rp->discovery_is_atomic()) {
rp->verify_no_references_recorded();
rp->enable_discovery();
- rp->setup_policy(clear_all_soft_refs);
+ rp->setup_policy(do_clear_all_soft_refs);
} else {
// collect() below will enable discovery as appropriate
}
- _gens[i]->collect(full, clear_all_soft_refs, size, is_tlab);
+ _gens[i]->collect(full, do_clear_all_soft_refs, size, is_tlab);
if (!rp->enqueuing_is_done()) {
rp->enqueue_discovered_references();
} else {
--- a/hotspot/src/share/vm/memory/genMarkSweep.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/memory/genMarkSweep.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc. 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
@@ -29,6 +29,13 @@
bool clear_all_softrefs) {
assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
+ GenCollectedHeap* gch = GenCollectedHeap::heap();
+#ifdef ASSERT
+ if (gch->collector_policy()->should_clear_all_soft_refs()) {
+ assert(clear_all_softrefs, "Policy should have been checked earlier");
+ }
+#endif
+
// hook up weak ref data so it can be used during Mark-Sweep
assert(ref_processor() == NULL, "no stomping");
assert(rp != NULL, "should be non-NULL");
@@ -44,7 +51,6 @@
// Increment the invocation count for the permanent generation, since it is
// implicitly collected whenever we do a full mark sweep collection.
- GenCollectedHeap* gch = GenCollectedHeap::heap();
gch->perm_gen()->stat_record()->invocations++;
// Capture heap size before collection for printing.
--- a/hotspot/src/share/vm/services/g1MemoryPool.cpp Wed Apr 21 01:13:15 2010 -0700
+++ b/hotspot/src/share/vm/services/g1MemoryPool.cpp Mon Apr 26 18:01:55 2010 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2007 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright 2007-2010 Sun Microsystems, Inc. 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
@@ -45,7 +45,7 @@
// See the comment at the top of g1MemoryPool.hpp
size_t G1MemoryPoolSuper::eden_space_used(G1CollectedHeap* g1h) {
- size_t young_list_length = g1h->young_list_length();
+ size_t young_list_length = g1h->young_list()->length();
size_t eden_used = young_list_length * HeapRegion::GrainBytes;
size_t survivor_used = survivor_space_used(g1h);
eden_used = subtract_up_to_zero(eden_used, survivor_used);