Tue, 21 Aug 2012 14:10:39 -0700
7185699: G1: Prediction model discrepancies
Summary: Correct the result value of G1CollectedHeap::pending_card_num(). Change the code that calculates the GC efficiency of a non-young heap region to use historical data from mixed GCs and the actual number of live bytes when predicting how long it would take to collect the region. Changes were also reviewed by Thomas Schatzl.
Reviewed-by: azeemj, brutisso
1 /*
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25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_VM_OPERATIONS_G1_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_VM_OPERATIONS_G1_HPP
28 #include "gc_implementation/shared/vmGCOperations.hpp"
30 // VM_operations for the G1 collector.
31 // VM_GC_Operation:
32 // - VM_CGC_Operation
33 // - VM_G1CollectFull
34 // - VM_G1OperationWithAllocRequest
35 // - VM_G1CollectForAllocation
36 // - VM_G1IncCollectionPause
38 class VM_G1OperationWithAllocRequest: public VM_GC_Operation {
39 protected:
40 size_t _word_size;
41 HeapWord* _result;
42 bool _pause_succeeded;
44 public:
45 VM_G1OperationWithAllocRequest(unsigned int gc_count_before,
46 size_t word_size,
47 GCCause::Cause gc_cause)
48 : VM_GC_Operation(gc_count_before, gc_cause),
49 _word_size(word_size), _result(NULL), _pause_succeeded(false) { }
50 HeapWord* result() { return _result; }
51 bool pause_succeeded() { return _pause_succeeded; }
52 };
54 class VM_G1CollectFull: public VM_GC_Operation {
55 public:
56 VM_G1CollectFull(unsigned int gc_count_before,
57 unsigned int full_gc_count_before,
58 GCCause::Cause cause)
59 : VM_GC_Operation(gc_count_before, cause, full_gc_count_before) { }
60 virtual VMOp_Type type() const { return VMOp_G1CollectFull; }
61 virtual void doit();
62 virtual const char* name() const {
63 return "full garbage-first collection";
64 }
65 };
67 class VM_G1CollectForAllocation: public VM_G1OperationWithAllocRequest {
68 public:
69 VM_G1CollectForAllocation(unsigned int gc_count_before,
70 size_t word_size);
71 virtual VMOp_Type type() const { return VMOp_G1CollectForAllocation; }
72 virtual void doit();
73 virtual const char* name() const {
74 return "garbage-first collection to satisfy allocation";
75 }
76 };
78 class VM_G1IncCollectionPause: public VM_G1OperationWithAllocRequest {
79 private:
80 bool _should_initiate_conc_mark;
81 bool _should_retry_gc;
82 double _target_pause_time_ms;
83 unsigned int _old_marking_cycles_completed_before;
84 public:
85 VM_G1IncCollectionPause(unsigned int gc_count_before,
86 size_t word_size,
87 bool should_initiate_conc_mark,
88 double target_pause_time_ms,
89 GCCause::Cause gc_cause);
90 virtual VMOp_Type type() const { return VMOp_G1IncCollectionPause; }
91 virtual bool doit_prologue();
92 virtual void doit();
93 virtual void doit_epilogue();
94 virtual const char* name() const {
95 return "garbage-first incremental collection pause";
96 }
97 bool should_retry_gc() const { return _should_retry_gc; }
98 };
100 // Concurrent GC stop-the-world operations such as remark and cleanup;
101 // consider sharing these with CMS's counterparts.
102 class VM_CGC_Operation: public VM_Operation {
103 VoidClosure* _cl;
104 const char* _printGCMessage;
105 bool _needs_pll;
107 protected:
108 // java.lang.ref.Reference support
109 void acquire_pending_list_lock();
110 void release_and_notify_pending_list_lock();
112 public:
113 VM_CGC_Operation(VoidClosure* cl, const char *printGCMsg, bool needs_pll)
114 : _cl(cl), _printGCMessage(printGCMsg), _needs_pll(needs_pll) { }
115 virtual VMOp_Type type() const { return VMOp_CGC_Operation; }
116 virtual void doit();
117 virtual bool doit_prologue();
118 virtual void doit_epilogue();
119 virtual const char* name() const {
120 return "concurrent gc";
121 }
122 };
124 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_VM_OPERATIONS_G1_HPP