Tue, 07 Apr 2015 10:53:51 +0200
8058354: SPECjvm2008-Derby -2.7% performance regression on Solaris-X64 starting with 9-b29
Summary: Allow use of large pages for auxiliary data structures in G1. Clean up existing interfaces.
Reviewed-by: jmasa, pliden, stefank
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25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP
28 #include "gc_implementation/g1/g1PageBasedVirtualSpace.hpp"
29 #include "memory/allocation.hpp"
30 #include "utilities/debug.hpp"
32 class G1MappingChangedListener VALUE_OBJ_CLASS_SPEC {
33 public:
34 // Fired after commit of the memory, i.e. the memory this listener is registered
35 // for can be accessed.
36 // Zero_filled indicates that the memory can be considered as filled with zero bytes
37 // when called.
38 virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled) = 0;
39 };
41 // Maps region based commit/uncommit requests to the underlying page sized virtual
42 // space.
43 class G1RegionToSpaceMapper : public CHeapObj<mtGC> {
44 private:
45 G1MappingChangedListener* _listener;
46 protected:
47 // Backing storage.
48 G1PageBasedVirtualSpace _storage;
50 size_t _region_granularity;
51 // Mapping management
52 BitMap _commit_map;
54 G1RegionToSpaceMapper(ReservedSpace rs, size_t used_size, size_t page_size, size_t region_granularity, MemoryType type);
56 void fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled);
57 public:
58 MemRegion reserved() { return _storage.reserved(); }
60 void set_mapping_changed_listener(G1MappingChangedListener* listener) { _listener = listener; }
62 virtual ~G1RegionToSpaceMapper() {
63 _commit_map.resize(0, /* in_resource_area */ false);
64 }
66 bool is_committed(uintptr_t idx) const {
67 return _commit_map.at(idx);
68 }
70 virtual void commit_regions(uint start_idx, size_t num_regions = 1) = 0;
71 virtual void uncommit_regions(uint start_idx, size_t num_regions = 1) = 0;
73 // Creates an appropriate G1RegionToSpaceMapper for the given parameters.
74 // The actual space to be used within the given reservation is given by actual_size.
75 // This is because some OSes need to round up the reservation size to guarantee
76 // alignment of page_size.
77 // The byte_translation_factor defines how many bytes in a region correspond to
78 // a single byte in the data structure this mapper is for.
79 // Eg. in the card table, this value corresponds to the size a single card
80 // table entry corresponds to in the heap.
81 static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs,
82 size_t actual_size,
83 size_t page_size,
84 size_t region_granularity,
85 size_t byte_translation_factor,
86 MemoryType type);
87 };
89 #endif /* SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP */