Mercurial > hg > truffle
annotate src/share/vm/memory/generationSpec.hpp @ 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 |
|---|---|
| date | Fri, 10 Oct 2014 15:51:58 +0200 |
| parents | da91efe96a93 |
| children |
| rev | line source |
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| 0 | 1 /* |
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6964458: Reimplement class meta-data storage to use native memory
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2 * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. |
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| 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #ifndef SHARE_VM_MEMORY_GENERATIONSPEC_HPP |
| 26 #define SHARE_VM_MEMORY_GENERATIONSPEC_HPP | |
| 27 | |
| 28 #include "memory/generation.hpp" | |
| 29 | |
| 0 | 30 // The specification of a generation. This class also encapsulates |
| 31 // some generation-specific behavior. This is done here rather than as a | |
| 32 // virtual function of Generation because these methods are needed in | |
| 33 // initialization of the Generations. | |
| 6197 | 34 class GenerationSpec : public CHeapObj<mtGC> { |
| 0 | 35 friend class VMStructs; |
| 36 private: | |
| 37 Generation::Name _name; | |
| 38 size_t _init_size; | |
| 39 size_t _max_size; | |
| 40 | |
| 41 public: | |
| 42 GenerationSpec(Generation::Name name, size_t init_size, size_t max_size) { | |
| 43 _name = name; | |
| 44 _init_size = init_size; | |
| 45 _max_size = max_size; | |
| 46 } | |
| 47 | |
| 48 Generation* init(ReservedSpace rs, int level, GenRemSet* remset); | |
| 49 | |
| 50 // Accessors | |
| 51 Generation::Name name() const { return _name; } | |
| 52 size_t init_size() const { return _init_size; } | |
| 53 void set_init_size(size_t size) { _init_size = size; } | |
| 54 size_t max_size() const { return _max_size; } | |
| 55 void set_max_size(size_t size) { _max_size = size; } | |
| 56 | |
| 57 // Alignment | |
| 58 void align(size_t alignment) { | |
| 59 set_init_size(align_size_up(init_size(), alignment)); | |
| 60 set_max_size(align_size_up(max_size(), alignment)); | |
| 61 } | |
| 62 | |
| 63 // Return the number of regions contained in the generation which | |
| 64 // might need to be independently covered by a remembered set. | |
| 65 virtual int n_covered_regions() const { return 1; } | |
| 66 }; | |
| 67 | |
| 68 typedef GenerationSpec* GenerationSpecPtr; | |
| 69 | |
| 1972 | 70 #endif // SHARE_VM_MEMORY_GENERATIONSPEC_HPP |