Mercurial > hg > truffle
comparison src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.cpp @ 20543:e7d0505c8a30
8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso
author | tschatzl |
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date | Fri, 10 Oct 2014 15:51:58 +0200 |
parents | 1f1d373cd044 |
children | 7848fc12602b |
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20542:0fcaab91d485 | 20543:e7d0505c8a30 |
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122 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) { | 122 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) { |
123 verify_region(mr, g1_young_gen, true); | 123 verify_region(mr, g1_young_gen, true); |
124 } | 124 } |
125 #endif | 125 #endif |
126 | 126 |
127 void G1SATBCardTableLoggingModRefBSChangedListener::on_commit(uint start_idx, size_t num_regions) { | 127 void G1SATBCardTableLoggingModRefBSChangedListener::on_commit(uint start_idx, size_t num_regions, bool zero_filled) { |
128 // Default value for a clean card on the card table is -1. So we cannot take advantage of the zero_filled parameter. | |
128 MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords); | 129 MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords); |
129 _card_table->clear(mr); | 130 _card_table->clear(mr); |
130 } | 131 } |
131 | 132 |
132 G1SATBCardTableLoggingModRefBS:: | 133 G1SATBCardTableLoggingModRefBS:: |