Mercurial > hg > openjdk > jigsaw > hotspot
changeset 4533:8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
Reviewed-by: johnc, ysr
| author | jmasa |
|---|---|
| date | Mon, 11 Feb 2013 10:31:56 -0800 |
| parents | 68fe50d4f1d5 |
| children | 83f27710f5f7 |
| files | src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp src/share/vm/memory/generation.cpp src/share/vm/memory/generation.hpp src/share/vm/memory/tenuredGeneration.cpp src/share/vm/memory/tenuredGeneration.hpp src/share/vm/runtime/vmStructs.cpp |
| diffstat | 7 files changed, 269 insertions(+), 230 deletions(-) [+] |
line wrap: on
line diff
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Fri Apr 05 10:20:04 2013 -0700 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Mon Feb 11 10:31:56 2013 -0800 @@ -48,6 +48,7 @@ #include "memory/iterator.hpp" #include "memory/referencePolicy.hpp" #include "memory/resourceArea.hpp" +#include "memory/tenuredGeneration.hpp" #include "oops/oop.inline.hpp" #include "prims/jvmtiExport.hpp" #include "runtime/globals_extension.hpp" @@ -916,7 +917,31 @@ return; } - size_t expand_bytes = 0; + // Compute some numbers about the state of the heap. + const size_t used_after_gc = used(); + const size_t capacity_after_gc = capacity(); + + CardGeneration::compute_new_size(); + + // Reset again after a possible resizing + cmsSpace()->reset_after_compaction(); + + assert(used() == used_after_gc && used_after_gc <= capacity(), + err_msg("used: " SIZE_FORMAT " used_after_gc: " SIZE_FORMAT + " capacity: " SIZE_FORMAT, used(), used_after_gc, capacity())); +} + +void ConcurrentMarkSweepGeneration::compute_new_size_free_list() { + assert_locked_or_safepoint(Heap_lock); + + // If incremental collection failed, we just want to expand + // to the limit. + if (incremental_collection_failed()) { + clear_incremental_collection_failed(); + grow_to_reserved(); + return; + } + double free_percentage = ((double) free()) / capacity(); double desired_free_percentage = (double) MinHeapFreeRatio / 100; double maximum_free_percentage = (double) MaxHeapFreeRatio / 100; @@ -925,9 +950,7 @@ if (free_percentage < desired_free_percentage) { size_t desired_capacity = (size_t)(used() / ((double) 1 - desired_free_percentage)); assert(desired_capacity >= capacity(), "invalid expansion size"); - expand_bytes = MAX2(desired_capacity - capacity(), MinHeapDeltaBytes); - } - if (expand_bytes > 0) { + size_t expand_bytes = MAX2(desired_capacity - capacity(), MinHeapDeltaBytes); if (PrintGCDetails && Verbose) { size_t desired_capacity = (size_t)(used() / ((double) 1 - desired_free_percentage)); gclog_or_tty->print_cr("\nFrom compute_new_size: "); @@ -961,6 +984,14 @@ gclog_or_tty->print_cr(" Expanded free fraction %f", ((double) free()) / capacity()); } + } else { + size_t desired_capacity = (size_t)(used() / ((double) 1 - desired_free_percentage)); + assert(desired_capacity <= capacity(), "invalid expansion size"); + size_t shrink_bytes = capacity() - desired_capacity; + // Don't shrink unless the delta is greater than the minimum shrink we want + if (shrink_bytes >= MinHeapDeltaBytes) { + shrink_free_list_by(shrink_bytes); + } } } @@ -1872,7 +1903,7 @@ assert_locked_or_safepoint(Heap_lock); FreelistLocker z(this); MetaspaceGC::compute_new_size(); - _cmsGen->compute_new_size(); + _cmsGen->compute_new_size_free_list(); } // A work method used by foreground collection to determine @@ -2601,6 +2632,10 @@ } void ConcurrentMarkSweepGeneration::gc_prologue(bool full) { + + _capacity_at_prologue = capacity(); + _used_at_prologue = used(); + // Delegate to CMScollector which knows how to coordinate between // this and any other CMS generations that it is responsible for // collecting. @@ -3300,6 +3335,26 @@ } +void ConcurrentMarkSweepGeneration::shrink_by(size_t bytes) { + assert_locked_or_safepoint(ExpandHeap_lock); + // Shrink committed space + _virtual_space.shrink_by(bytes); + // Shrink space; this also shrinks the space's BOT + _cmsSpace->set_end((HeapWord*) _virtual_space.high()); + size_t new_word_size = heap_word_size(_cmsSpace->capacity()); + // Shrink the shared block offset array + _bts->resize(new_word_size); + MemRegion mr(_cmsSpace->bottom(), new_word_size); + // Shrink the card table + Universe::heap()->barrier_set()->resize_covered_region(mr); + + if (Verbose && PrintGC) { + size_t new_mem_size = _virtual_space.committed_size(); + size_t old_mem_size = new_mem_size + bytes; + gclog_or_tty->print_cr("Shrinking %s from " SIZE_FORMAT "K to " SIZE_FORMAT "K", + name(), old_mem_size/K, new_mem_size/K); + } +} void ConcurrentMarkSweepGeneration::shrink(size_t bytes) { assert_locked_or_safepoint(Heap_lock); @@ -3351,7 +3406,7 @@ return success; } -void ConcurrentMarkSweepGeneration::shrink_by(size_t bytes) { +void ConcurrentMarkSweepGeneration::shrink_free_list_by(size_t bytes) { assert_locked_or_safepoint(Heap_lock); assert_lock_strong(freelistLock()); // XXX Fix when compaction is implemented. @@ -9074,51 +9129,6 @@ } } -// The desired expansion delta is computed so that: -// . desired free percentage or greater is used -void ASConcurrentMarkSweepGeneration::compute_new_size() { - assert_locked_or_safepoint(Heap_lock); - - GenCollectedHeap* gch = (GenCollectedHeap*) GenCollectedHeap::heap(); - - // If incremental collection failed, we just want to expand - // to the limit. - if (incremental_collection_failed()) { - clear_incremental_collection_failed(); - grow_to_reserved(); - return; - } - - assert(UseAdaptiveSizePolicy, "Should be using adaptive sizing"); - - assert(gch->kind() == CollectedHeap::GenCollectedHeap, - "Wrong type of heap"); - int prev_level = level() - 1; - assert(prev_level >= 0, "The cms generation is the lowest generation"); - Generation* prev_gen = gch->get_gen(prev_level); - assert(prev_gen->kind() == Generation::ASParNew, - "Wrong type of young generation"); - ParNewGeneration* younger_gen = (ParNewGeneration*) prev_gen; - size_t cur_eden = younger_gen->eden()->capacity(); - CMSAdaptiveSizePolicy* size_policy = cms_size_policy(); - size_t cur_promo = free(); - size_policy->compute_tenured_generation_free_space(cur_promo, - max_available(), - cur_eden); - resize(cur_promo, size_policy->promo_size()); - - // Record the new size of the space in the cms generation - // that is available for promotions. This is temporary. - // It should be the desired promo size. - size_policy->avg_cms_promo()->sample(free()); - size_policy->avg_old_live()->sample(used()); - - if (UsePerfData) { - CMSGCAdaptivePolicyCounters* counters = gc_adaptive_policy_counters(); - counters->update_cms_capacity_counter(capacity()); - } -} - void ASConcurrentMarkSweepGeneration::shrink_by(size_t desired_bytes) { assert_locked_or_safepoint(Heap_lock); assert_lock_strong(freelistLock());
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Fri Apr 05 10:20:04 2013 -0700 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Mon Feb 11 10:31:56 2013 -0800 @@ -60,6 +60,7 @@ class FreeChunk; class PromotionInfo; class ScanMarkedObjectsAgainCarefullyClosure; +class TenuredGeneration; // A generic CMS bit map. It's the basis for both the CMS marking bit map // as well as for the mod union table (in each case only a subset of the @@ -810,9 +811,6 @@ // used regions of each generation to limit the extent of sweep void save_sweep_limits(); - // Resize the generations included in the collector. - void compute_new_size(); - // A work method used by foreground collection to determine // what type of collection (compacting or not, continuing or fresh) // it should do. @@ -909,6 +907,9 @@ void releaseFreelistLocks() const; bool haveFreelistLocks() const; + // Adjust size of underlying generation + void compute_new_size(); + // GC prologue and epilogue void gc_prologue(bool full); void gc_epilogue(bool full); @@ -1082,7 +1083,7 @@ protected: // Shrink generation by specified size (returns false if unable to shrink) - virtual void shrink_by(size_t bytes); + void shrink_free_list_by(size_t bytes); // Update statistics for GC virtual void update_gc_stats(int level, bool full); @@ -1233,6 +1234,7 @@ CMSExpansionCause::Cause cause); virtual bool expand(size_t bytes, size_t expand_bytes); void shrink(size_t bytes); + void shrink_by(size_t bytes); HeapWord* expand_and_par_lab_allocate(CMSParGCThreadState* ps, size_t word_sz); bool expand_and_ensure_spooling_space(PromotionInfo* promo); @@ -1293,7 +1295,13 @@ bool must_be_youngest() const { return false; } bool must_be_oldest() const { return true; } - void compute_new_size(); + // Resize the generation after a compacting GC. The + // generation can be treated as a contiguous space + // after the compaction. + virtual void compute_new_size(); + // Resize the generation after a non-compacting + // collection. + void compute_new_size_free_list(); CollectionTypes debug_collection_type() { return _debug_collection_type; } void rotate_debug_collection_type(); @@ -1315,7 +1323,6 @@ virtual void shrink_by(size_t bytes); public: - virtual void compute_new_size(); ASConcurrentMarkSweepGeneration(ReservedSpace rs, size_t initial_byte_size, int level, CardTableRS* ct, bool use_adaptive_freelists,
--- a/src/share/vm/memory/generation.cpp Fri Apr 05 10:20:04 2013 -0700 +++ b/src/share/vm/memory/generation.cpp Mon Feb 11 10:31:56 2013 -0800 @@ -382,7 +382,9 @@ CardGeneration::CardGeneration(ReservedSpace rs, size_t initial_byte_size, int level, GenRemSet* remset) : - Generation(rs, initial_byte_size, level), _rs(remset) + Generation(rs, initial_byte_size, level), _rs(remset), + _shrink_factor(0), _min_heap_delta_bytes(), _capacity_at_prologue(), + _used_at_prologue() { HeapWord* start = (HeapWord*)rs.base(); size_t reserved_byte_size = rs.size(); @@ -406,6 +408,9 @@ // the end if we try. guarantee(_rs->is_aligned(reserved_mr.end()), "generation must be card aligned"); } + _min_heap_delta_bytes = MinHeapDeltaBytes; + _capacity_at_prologue = initial_byte_size; + _used_at_prologue = 0; } bool CardGeneration::expand(size_t bytes, size_t expand_bytes) { @@ -457,6 +462,160 @@ } +void CardGeneration::compute_new_size() { + assert(_shrink_factor <= 100, "invalid shrink factor"); + size_t current_shrink_factor = _shrink_factor; + _shrink_factor = 0; + + // We don't have floating point command-line arguments + // Note: argument processing ensures that MinHeapFreeRatio < 100. + const double minimum_free_percentage = MinHeapFreeRatio / 100.0; + const double maximum_used_percentage = 1.0 - minimum_free_percentage; + + // Compute some numbers about the state of the heap. + const size_t used_after_gc = used(); + const size_t capacity_after_gc = capacity(); + + const double min_tmp = used_after_gc / maximum_used_percentage; + size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(max_uintx)); + // Don't shrink less than the initial generation size + minimum_desired_capacity = MAX2(minimum_desired_capacity, + spec()->init_size()); + assert(used_after_gc <= minimum_desired_capacity, "sanity check"); + + if (PrintGC && Verbose) { + const size_t free_after_gc = free(); + const double free_percentage = ((double)free_after_gc) / capacity_after_gc; + gclog_or_tty->print_cr("TenuredGeneration::compute_new_size: "); + gclog_or_tty->print_cr(" " + " minimum_free_percentage: %6.2f" + " maximum_used_percentage: %6.2f", + minimum_free_percentage, + maximum_used_percentage); + gclog_or_tty->print_cr(" " + " free_after_gc : %6.1fK" + " used_after_gc : %6.1fK" + " capacity_after_gc : %6.1fK", + free_after_gc / (double) K, + used_after_gc / (double) K, + capacity_after_gc / (double) K); + gclog_or_tty->print_cr(" " + " free_percentage: %6.2f", + free_percentage); + } + + if (capacity_after_gc < minimum_desired_capacity) { + // If we have less free space than we want then expand + size_t expand_bytes = minimum_desired_capacity - capacity_after_gc; + // Don't expand unless it's significant + if (expand_bytes >= _min_heap_delta_bytes) { + expand(expand_bytes, 0); // safe if expansion fails + } + if (PrintGC && Verbose) { + gclog_or_tty->print_cr(" expanding:" + " minimum_desired_capacity: %6.1fK" + " expand_bytes: %6.1fK" + " _min_heap_delta_bytes: %6.1fK", + minimum_desired_capacity / (double) K, + expand_bytes / (double) K, + _min_heap_delta_bytes / (double) K); + } + return; + } + + // No expansion, now see if we want to shrink + size_t shrink_bytes = 0; + // We would never want to shrink more than this + size_t max_shrink_bytes = capacity_after_gc - minimum_desired_capacity; + + if (MaxHeapFreeRatio < 100) { + const double maximum_free_percentage = MaxHeapFreeRatio / 100.0; + const double minimum_used_percentage = 1.0 - maximum_free_percentage; + const double max_tmp = used_after_gc / minimum_used_percentage; + size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx)); + maximum_desired_capacity = MAX2(maximum_desired_capacity, + spec()->init_size()); + if (PrintGC && Verbose) { + gclog_or_tty->print_cr(" " + " maximum_free_percentage: %6.2f" + " minimum_used_percentage: %6.2f", + maximum_free_percentage, + minimum_used_percentage); + gclog_or_tty->print_cr(" " + " _capacity_at_prologue: %6.1fK" + " minimum_desired_capacity: %6.1fK" + " maximum_desired_capacity: %6.1fK", + _capacity_at_prologue / (double) K, + minimum_desired_capacity / (double) K, + maximum_desired_capacity / (double) K); + } + assert(minimum_desired_capacity <= maximum_desired_capacity, + "sanity check"); + + if (capacity_after_gc > maximum_desired_capacity) { + // Capacity too large, compute shrinking size + shrink_bytes = capacity_after_gc - maximum_desired_capacity; + // We don't want shrink all the way back to initSize if people call + // System.gc(), because some programs do that between "phases" and then + // we'd just have to grow the heap up again for the next phase. So we + // damp the shrinking: 0% on the first call, 10% on the second call, 40% + // on the third call, and 100% by the fourth call. But if we recompute + // size without shrinking, it goes back to 0%. + shrink_bytes = shrink_bytes / 100 * current_shrink_factor; + assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size"); + if (current_shrink_factor == 0) { + _shrink_factor = 10; + } else { + _shrink_factor = MIN2(current_shrink_factor * 4, (size_t) 100); + } + if (PrintGC && Verbose) { + gclog_or_tty->print_cr(" " + " shrinking:" + " initSize: %.1fK" + " maximum_desired_capacity: %.1fK", + spec()->init_size() / (double) K, + maximum_desired_capacity / (double) K); + gclog_or_tty->print_cr(" " + " shrink_bytes: %.1fK" + " current_shrink_factor: %d" + " new shrink factor: %d" + " _min_heap_delta_bytes: %.1fK", + shrink_bytes / (double) K, + current_shrink_factor, + _shrink_factor, + _min_heap_delta_bytes / (double) K); + } + } + } + + if (capacity_after_gc > _capacity_at_prologue) { + // We might have expanded for promotions, in which case we might want to + // take back that expansion if there's room after GC. That keeps us from + // stretching the heap with promotions when there's plenty of room. + size_t expansion_for_promotion = capacity_after_gc - _capacity_at_prologue; + expansion_for_promotion = MIN2(expansion_for_promotion, max_shrink_bytes); + // We have two shrinking computations, take the largest + shrink_bytes = MAX2(shrink_bytes, expansion_for_promotion); + assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size"); + if (PrintGC && Verbose) { + gclog_or_tty->print_cr(" " + " aggressive shrinking:" + " _capacity_at_prologue: %.1fK" + " capacity_after_gc: %.1fK" + " expansion_for_promotion: %.1fK" + " shrink_bytes: %.1fK", + capacity_after_gc / (double) K, + _capacity_at_prologue / (double) K, + expansion_for_promotion / (double) K, + shrink_bytes / (double) K); + } + } + // Don't shrink unless it's significant + if (shrink_bytes >= _min_heap_delta_bytes) { + shrink(shrink_bytes); + } +} + // Currently nothing to do. void CardGeneration::prepare_for_verify() {}
--- a/src/share/vm/memory/generation.hpp Fri Apr 05 10:20:04 2013 -0700 +++ b/src/share/vm/memory/generation.hpp Mon Feb 11 10:31:56 2013 -0800 @@ -634,6 +634,17 @@ // This is local to this generation. BlockOffsetSharedArray* _bts; + // current shrinking effect: this damps shrinking when the heap gets empty. + size_t _shrink_factor; + + size_t _min_heap_delta_bytes; // Minimum amount to expand. + + // Some statistics from before gc started. + // These are gathered in the gc_prologue (and should_collect) + // to control growing/shrinking policy in spite of promotions. + size_t _capacity_at_prologue; + size_t _used_at_prologue; + CardGeneration(ReservedSpace rs, size_t initial_byte_size, int level, GenRemSet* remset); @@ -644,6 +655,11 @@ // necessarily the full "bytes") was done. virtual bool expand(size_t bytes, size_t expand_bytes); + // Shrink generation with specified size (returns false if unable to shrink) + virtual void shrink(size_t bytes) = 0; + + virtual void compute_new_size(); + virtual void clear_remembered_set(); virtual void invalidate_remembered_set(); @@ -667,7 +683,6 @@ friend class VM_PopulateDumpSharedSpace; protected: - size_t _min_heap_delta_bytes; // Minimum amount to expand. ContiguousSpace* _the_space; // actual space holding objects WaterMark _last_gc; // watermark between objects allocated before // and after last GC. @@ -688,11 +703,10 @@ public: OneContigSpaceCardGeneration(ReservedSpace rs, size_t initial_byte_size, - size_t min_heap_delta_bytes, int level, GenRemSet* remset, ContiguousSpace* space) : CardGeneration(rs, initial_byte_size, level, remset), - _the_space(space), _min_heap_delta_bytes(min_heap_delta_bytes) + _the_space(space) {} inline bool is_in(const void* p) const;
--- a/src/share/vm/memory/tenuredGeneration.cpp Fri Apr 05 10:20:04 2013 -0700 +++ b/src/share/vm/memory/tenuredGeneration.cpp Mon Feb 11 10:31:56 2013 -0800 @@ -39,7 +39,7 @@ size_t initial_byte_size, int level, GenRemSet* remset) : OneContigSpaceCardGeneration(rs, initial_byte_size, - MinHeapDeltaBytes, level, remset, NULL) + level, remset, NULL) { HeapWord* bottom = (HeapWord*) _virtual_space.low(); HeapWord* end = (HeapWord*) _virtual_space.high(); @@ -86,162 +86,6 @@ return "tenured generation"; } -void TenuredGeneration::compute_new_size() { - assert(_shrink_factor <= 100, "invalid shrink factor"); - size_t current_shrink_factor = _shrink_factor; - _shrink_factor = 0; - - // We don't have floating point command-line arguments - // Note: argument processing ensures that MinHeapFreeRatio < 100. - const double minimum_free_percentage = MinHeapFreeRatio / 100.0; - const double maximum_used_percentage = 1.0 - minimum_free_percentage; - - // Compute some numbers about the state of the heap. - const size_t used_after_gc = used(); - const size_t capacity_after_gc = capacity(); - - const double min_tmp = used_after_gc / maximum_used_percentage; - size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(max_uintx)); - // Don't shrink less than the initial generation size - minimum_desired_capacity = MAX2(minimum_desired_capacity, - spec()->init_size()); - assert(used_after_gc <= minimum_desired_capacity, "sanity check"); - - if (PrintGC && Verbose) { - const size_t free_after_gc = free(); - const double free_percentage = ((double)free_after_gc) / capacity_after_gc; - gclog_or_tty->print_cr("TenuredGeneration::compute_new_size: "); - gclog_or_tty->print_cr(" " - " minimum_free_percentage: %6.2f" - " maximum_used_percentage: %6.2f", - minimum_free_percentage, - maximum_used_percentage); - gclog_or_tty->print_cr(" " - " free_after_gc : %6.1fK" - " used_after_gc : %6.1fK" - " capacity_after_gc : %6.1fK", - free_after_gc / (double) K, - used_after_gc / (double) K, - capacity_after_gc / (double) K); - gclog_or_tty->print_cr(" " - " free_percentage: %6.2f", - free_percentage); - } - - if (capacity_after_gc < minimum_desired_capacity) { - // If we have less free space than we want then expand - size_t expand_bytes = minimum_desired_capacity - capacity_after_gc; - // Don't expand unless it's significant - if (expand_bytes >= _min_heap_delta_bytes) { - expand(expand_bytes, 0); // safe if expansion fails - } - if (PrintGC && Verbose) { - gclog_or_tty->print_cr(" expanding:" - " minimum_desired_capacity: %6.1fK" - " expand_bytes: %6.1fK" - " _min_heap_delta_bytes: %6.1fK", - minimum_desired_capacity / (double) K, - expand_bytes / (double) K, - _min_heap_delta_bytes / (double) K); - } - return; - } - - // No expansion, now see if we want to shrink - size_t shrink_bytes = 0; - // We would never want to shrink more than this - size_t max_shrink_bytes = capacity_after_gc - minimum_desired_capacity; - - if (MaxHeapFreeRatio < 100) { - const double maximum_free_percentage = MaxHeapFreeRatio / 100.0; - const double minimum_used_percentage = 1.0 - maximum_free_percentage; - const double max_tmp = used_after_gc / minimum_used_percentage; - size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx)); - maximum_desired_capacity = MAX2(maximum_desired_capacity, - spec()->init_size()); - if (PrintGC && Verbose) { - gclog_or_tty->print_cr(" " - " maximum_free_percentage: %6.2f" - " minimum_used_percentage: %6.2f", - maximum_free_percentage, - minimum_used_percentage); - gclog_or_tty->print_cr(" " - " _capacity_at_prologue: %6.1fK" - " minimum_desired_capacity: %6.1fK" - " maximum_desired_capacity: %6.1fK", - _capacity_at_prologue / (double) K, - minimum_desired_capacity / (double) K, - maximum_desired_capacity / (double) K); - } - assert(minimum_desired_capacity <= maximum_desired_capacity, - "sanity check"); - - if (capacity_after_gc > maximum_desired_capacity) { - // Capacity too large, compute shrinking size - shrink_bytes = capacity_after_gc - maximum_desired_capacity; - // We don't want shrink all the way back to initSize if people call - // System.gc(), because some programs do that between "phases" and then - // we'd just have to grow the heap up again for the next phase. So we - // damp the shrinking: 0% on the first call, 10% on the second call, 40% - // on the third call, and 100% by the fourth call. But if we recompute - // size without shrinking, it goes back to 0%. - shrink_bytes = shrink_bytes / 100 * current_shrink_factor; - assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size"); - if (current_shrink_factor == 0) { - _shrink_factor = 10; - } else { - _shrink_factor = MIN2(current_shrink_factor * 4, (size_t) 100); - } - if (PrintGC && Verbose) { - gclog_or_tty->print_cr(" " - " shrinking:" - " initSize: %.1fK" - " maximum_desired_capacity: %.1fK", - spec()->init_size() / (double) K, - maximum_desired_capacity / (double) K); - gclog_or_tty->print_cr(" " - " shrink_bytes: %.1fK" - " current_shrink_factor: %d" - " new shrink factor: %d" - " _min_heap_delta_bytes: %.1fK", - shrink_bytes / (double) K, - current_shrink_factor, - _shrink_factor, - _min_heap_delta_bytes / (double) K); - } - } - } - - if (capacity_after_gc > _capacity_at_prologue) { - // We might have expanded for promotions, in which case we might want to - // take back that expansion if there's room after GC. That keeps us from - // stretching the heap with promotions when there's plenty of room. - size_t expansion_for_promotion = capacity_after_gc - _capacity_at_prologue; - expansion_for_promotion = MIN2(expansion_for_promotion, max_shrink_bytes); - // We have two shrinking computations, take the largest - shrink_bytes = MAX2(shrink_bytes, expansion_for_promotion); - assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size"); - if (PrintGC && Verbose) { - gclog_or_tty->print_cr(" " - " aggressive shrinking:" - " _capacity_at_prologue: %.1fK" - " capacity_after_gc: %.1fK" - " expansion_for_promotion: %.1fK" - " shrink_bytes: %.1fK", - capacity_after_gc / (double) K, - _capacity_at_prologue / (double) K, - expansion_for_promotion / (double) K, - shrink_bytes / (double) K); - } - } - // Don't shrink unless it's significant - if (shrink_bytes >= _min_heap_delta_bytes) { - shrink(shrink_bytes); - } - assert(used() == used_after_gc && used_after_gc <= capacity(), - "sanity check"); -} - void TenuredGeneration::gc_prologue(bool full) { _capacity_at_prologue = capacity(); _used_at_prologue = used(); @@ -312,6 +156,19 @@ size, is_tlab); } +void TenuredGeneration::compute_new_size() { + assert_locked_or_safepoint(Heap_lock); + + // Compute some numbers about the state of the heap. + const size_t used_after_gc = used(); + const size_t capacity_after_gc = capacity(); + + CardGeneration::compute_new_size(); + + assert(used() == used_after_gc && used_after_gc <= capacity(), + err_msg("used: " SIZE_FORMAT " used_after_gc: " SIZE_FORMAT + " capacity: " SIZE_FORMAT, used(), used_after_gc, capacity())); +} void TenuredGeneration::update_gc_stats(int current_level, bool full) { // If the next lower level(s) has been collected, gather any statistics
--- a/src/share/vm/memory/tenuredGeneration.hpp Fri Apr 05 10:20:04 2013 -0700 +++ b/src/share/vm/memory/tenuredGeneration.hpp Mon Feb 11 10:31:56 2013 -0800 @@ -38,13 +38,6 @@ class TenuredGeneration: public OneContigSpaceCardGeneration { friend class VMStructs; protected: - // current shrinking effect: this damps shrinking when the heap gets empty. - size_t _shrink_factor; - // Some statistics from before gc started. - // These are gathered in the gc_prologue (and should_collect) - // to control growing/shrinking policy in spite of promotions. - size_t _capacity_at_prologue; - size_t _used_at_prologue; #if INCLUDE_ALL_GCS // To support parallel promotion: an array of parallel allocation @@ -80,9 +73,6 @@ return !CollectGen0First; } - // Mark sweep support - void compute_new_size(); - virtual void gc_prologue(bool full); virtual void gc_epilogue(bool full); bool should_collect(bool full, @@ -93,6 +83,7 @@ bool clear_all_soft_refs, size_t size, bool is_tlab); + virtual void compute_new_size(); #if INCLUDE_ALL_GCS // Overrides.
--- a/src/share/vm/runtime/vmStructs.cpp Fri Apr 05 10:20:04 2013 -0700 +++ b/src/share/vm/runtime/vmStructs.cpp Mon Feb 11 10:31:56 2013 -0800 @@ -478,6 +478,9 @@ \ nonstatic_field(CardGeneration, _rs, GenRemSet*) \ nonstatic_field(CardGeneration, _bts, BlockOffsetSharedArray*) \ + nonstatic_field(CardGeneration, _shrink_factor, size_t) \ + nonstatic_field(CardGeneration, _capacity_at_prologue, size_t) \ + nonstatic_field(CardGeneration, _used_at_prologue, size_t) \ \ nonstatic_field(CardTableModRefBS, _whole_heap, const MemRegion) \ nonstatic_field(CardTableModRefBS, _guard_index, const size_t) \ @@ -548,8 +551,6 @@ nonstatic_field(Space, _bottom, HeapWord*) \ nonstatic_field(Space, _end, HeapWord*) \ \ - nonstatic_field(TenuredGeneration, _shrink_factor, size_t) \ - nonstatic_field(TenuredGeneration, _capacity_at_prologue, size_t) \ nonstatic_field(ThreadLocalAllocBuffer, _start, HeapWord*) \ nonstatic_field(ThreadLocalAllocBuffer, _top, HeapWord*) \ nonstatic_field(ThreadLocalAllocBuffer, _end, HeapWord*) \