From be8fe592d31583e67d2c8189b49441944760e315 Mon Sep 17 00:00:00 2001 From: apetrusenko Date: Fri, 16 Apr 2010 08:48:16 -0700 Subject: [PATCH] 6942253: G1: replace G1ParallelGCAllocBufferSize with YoungPLABSize and OldPLABSize Summary: Replaces the G1-specific parameter with the existing ones that are used by the other GCs (YoungPLABSize and OldPLABSize) Reviewed-by: tonyp, johnc --- .../gc_implementation/g1/g1CollectedHeap.cpp | 24 ++++++++ .../gc_implementation/g1/g1CollectedHeap.hpp | 58 +++++++++++-------- .../g1/g1CollectorPolicy.cpp | 9 +++ .../vm/gc_implementation/g1/g1_globals.hpp | 3 - 4 files changed, 68 insertions(+), 26 deletions(-) diff --git a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp index c1baa6ee82..6857d8fda9 100644 --- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp +++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp @@ -2946,6 +2946,25 @@ G1CollectedHeap::do_collection_pause_at_safepoint() { } } +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 @@ -3680,6 +3699,8 @@ G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, int queue_num) _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), @@ -3706,6 +3727,9 @@ G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, int queue_num) _overflowed_refs = new OverflowQueue(10); + _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer; + _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer; + _start = os::elapsedTime(); } diff --git a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp index 54715bd7b9..478e658809 100644 --- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp +++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp @@ -232,6 +232,9 @@ private: // 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); @@ -1367,12 +1370,18 @@ private: return BitsPerWord << shifter(); } - static size_t gclab_word_size() { - return G1ParallelGCAllocBufferSize / HeapWordSize; + size_t gclab_word_size() const { + return _gclab_word_size; + } + + // 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 bits_in_bitmap = gclab_word_size() >> shifter(); + 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 +1391,13 @@ private: 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 +1492,7 @@ public: 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 +1504,10 @@ public: } } - 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 +1517,10 @@ private: 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 +1559,10 @@ protected: typedef GrowableArray 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 +1631,7 @@ public: 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 +1696,15 @@ public: 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 +1798,9 @@ public: 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); } } diff --git a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp index 19e22d78b7..d88c2fc624 100644 --- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp +++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp @@ -209,6 +209,15 @@ G1CollectorPolicy::G1CollectorPolicy() : 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; diff --git a/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp b/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp index fca2f43c88..7e74f68d4d 100644 --- a/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp +++ b/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp @@ -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") \ \ -- GitLab