Tue, 03 May 2011 10:30:34 -0700
7041789: 30% perf regression with c2/arm following 7017732
Summary: Implement a more accurate is_scavengable()
Reviewed-by: stefank, jcoomes, ysr
1 /*
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13 * accompanied this code).
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25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARALLELSCAVENGEHEAP_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARALLELSCAVENGEHEAP_HPP
28 #include "gc_implementation/parallelScavenge/objectStartArray.hpp"
29 #include "gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp"
30 #include "gc_implementation/parallelScavenge/psOldGen.hpp"
31 #include "gc_implementation/parallelScavenge/psPermGen.hpp"
32 #include "gc_implementation/parallelScavenge/psYoungGen.hpp"
33 #include "gc_implementation/shared/gcPolicyCounters.hpp"
34 #include "gc_interface/collectedHeap.inline.hpp"
35 #include "utilities/ostream.hpp"
37 class AdjoiningGenerations;
38 class GCTaskManager;
39 class PSAdaptiveSizePolicy;
40 class GenerationSizer;
41 class CollectorPolicy;
43 class ParallelScavengeHeap : public CollectedHeap {
44 friend class VMStructs;
45 private:
46 static PSYoungGen* _young_gen;
47 static PSOldGen* _old_gen;
48 static PSPermGen* _perm_gen;
50 // Sizing policy for entire heap
51 static PSAdaptiveSizePolicy* _size_policy;
52 static PSGCAdaptivePolicyCounters* _gc_policy_counters;
54 static ParallelScavengeHeap* _psh;
56 size_t _perm_gen_alignment;
57 size_t _young_gen_alignment;
58 size_t _old_gen_alignment;
60 GenerationSizer* _collector_policy;
62 inline size_t set_alignment(size_t& var, size_t val);
64 // Collection of generations that are adjacent in the
65 // space reserved for the heap.
66 AdjoiningGenerations* _gens;
68 static GCTaskManager* _gc_task_manager; // The task manager.
70 protected:
71 static inline size_t total_invocations();
72 HeapWord* allocate_new_tlab(size_t size);
74 public:
75 ParallelScavengeHeap() : CollectedHeap() {
76 set_alignment(_perm_gen_alignment, intra_heap_alignment());
77 set_alignment(_young_gen_alignment, intra_heap_alignment());
78 set_alignment(_old_gen_alignment, intra_heap_alignment());
79 }
81 // For use by VM operations
82 enum CollectionType {
83 Scavenge,
84 MarkSweep
85 };
87 ParallelScavengeHeap::Name kind() const {
88 return CollectedHeap::ParallelScavengeHeap;
89 }
91 CollectorPolicy* collector_policy() const { return (CollectorPolicy*) _collector_policy; }
92 // GenerationSizer* collector_policy() const { return _collector_policy; }
94 static PSYoungGen* young_gen() { return _young_gen; }
95 static PSOldGen* old_gen() { return _old_gen; }
96 static PSPermGen* perm_gen() { return _perm_gen; }
98 virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
100 static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
102 static ParallelScavengeHeap* heap();
104 static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
106 AdjoiningGenerations* gens() { return _gens; }
108 // Returns JNI_OK on success
109 virtual jint initialize();
111 void post_initialize();
112 void update_counters();
113 // The alignment used for the various generations.
114 size_t perm_gen_alignment() const { return _perm_gen_alignment; }
115 size_t young_gen_alignment() const { return _young_gen_alignment; }
116 size_t old_gen_alignment() const { return _old_gen_alignment; }
118 // The alignment used for eden and survivors within the young gen
119 // and for boundary between young gen and old gen.
120 size_t intra_heap_alignment() const { return 64 * K; }
122 size_t capacity() const;
123 size_t used() const;
125 // Return "true" if all generations (but perm) have reached the
126 // maximal committed limit that they can reach, without a garbage
127 // collection.
128 virtual bool is_maximal_no_gc() const;
130 // Return true if the reference points to an object that
131 // can be moved in a partial collection. For currently implemented
132 // generational collectors that means during a collection of
133 // the young gen.
134 virtual bool is_scavengable(const void* addr);
136 // Does this heap support heap inspection? (+PrintClassHistogram)
137 bool supports_heap_inspection() const { return true; }
139 size_t permanent_capacity() const;
140 size_t permanent_used() const;
142 size_t max_capacity() const;
144 // Whether p is in the allocated part of the heap
145 bool is_in(const void* p) const;
147 bool is_in_reserved(const void* p) const;
148 bool is_in_permanent(const void *p) const { // reserved part
149 return perm_gen()->reserved().contains(p);
150 }
152 #ifdef ASSERT
153 virtual bool is_in_partial_collection(const void *p);
154 #endif
156 bool is_permanent(const void *p) const { // committed part
157 return perm_gen()->is_in(p);
158 }
160 inline bool is_in_young(oop p); // reserved part
161 inline bool is_in_old_or_perm(oop p); // reserved part
163 // Memory allocation. "gc_time_limit_was_exceeded" will
164 // be set to true if the adaptive size policy determine that
165 // an excessive amount of time is being spent doing collections
166 // and caused a NULL to be returned. If a NULL is not returned,
167 // "gc_time_limit_was_exceeded" has an undefined meaning.
169 HeapWord* mem_allocate(size_t size,
170 bool is_noref,
171 bool is_tlab,
172 bool* gc_overhead_limit_was_exceeded);
173 HeapWord* failed_mem_allocate(size_t size, bool is_tlab);
175 HeapWord* permanent_mem_allocate(size_t size);
176 HeapWord* failed_permanent_mem_allocate(size_t size);
178 // Support for System.gc()
179 void collect(GCCause::Cause cause);
181 // This interface assumes that it's being called by the
182 // vm thread. It collects the heap assuming that the
183 // heap lock is already held and that we are executing in
184 // the context of the vm thread.
185 void collect_as_vm_thread(GCCause::Cause cause);
187 // These also should be called by the vm thread at a safepoint (e.g., from a
188 // VM operation).
189 //
190 // The first collects the young generation only, unless the scavenge fails; it
191 // will then attempt a full gc. The second collects the entire heap; if
192 // maximum_compaction is true, it will compact everything and clear all soft
193 // references.
194 inline void invoke_scavenge();
195 inline void invoke_full_gc(bool maximum_compaction);
197 size_t large_typearray_limit() { return FastAllocateSizeLimit; }
199 bool supports_inline_contig_alloc() const { return !UseNUMA; }
201 HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord**)-1; }
202 HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
204 void ensure_parsability(bool retire_tlabs);
205 void accumulate_statistics_all_tlabs();
206 void resize_all_tlabs();
208 size_t unsafe_max_alloc();
210 bool supports_tlab_allocation() const { return true; }
212 size_t tlab_capacity(Thread* thr) const;
213 size_t unsafe_max_tlab_alloc(Thread* thr) const;
215 // Can a compiler initialize a new object without store barriers?
216 // This permission only extends from the creation of a new object
217 // via a TLAB up to the first subsequent safepoint.
218 virtual bool can_elide_tlab_store_barriers() const {
219 return true;
220 }
222 virtual bool card_mark_must_follow_store() const {
223 return false;
224 }
226 // Return true if we don't we need a store barrier for
227 // initializing stores to an object at this address.
228 virtual bool can_elide_initializing_store_barrier(oop new_obj);
230 // Can a compiler elide a store barrier when it writes
231 // a permanent oop into the heap? Applies when the compiler
232 // is storing x to the heap, where x->is_perm() is true.
233 virtual bool can_elide_permanent_oop_store_barriers() const {
234 return true;
235 }
237 void oop_iterate(OopClosure* cl);
238 void object_iterate(ObjectClosure* cl);
239 void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
240 void permanent_oop_iterate(OopClosure* cl);
241 void permanent_object_iterate(ObjectClosure* cl);
243 HeapWord* block_start(const void* addr) const;
244 size_t block_size(const HeapWord* addr) const;
245 bool block_is_obj(const HeapWord* addr) const;
247 jlong millis_since_last_gc();
249 void prepare_for_verify();
250 void print() const;
251 void print_on(outputStream* st) const;
252 virtual void print_gc_threads_on(outputStream* st) const;
253 virtual void gc_threads_do(ThreadClosure* tc) const;
254 virtual void print_tracing_info() const;
256 void verify(bool allow_dirty, bool silent, bool /* option */);
258 void print_heap_change(size_t prev_used);
260 // Resize the young generation. The reserved space for the
261 // generation may be expanded in preparation for the resize.
262 void resize_young_gen(size_t eden_size, size_t survivor_size);
264 // Resize the old generation. The reserved space for the
265 // generation may be expanded in preparation for the resize.
266 void resize_old_gen(size_t desired_free_space);
268 // Save the tops of the spaces in all generations
269 void record_gen_tops_before_GC() PRODUCT_RETURN;
271 // Mangle the unused parts of all spaces in the heap
272 void gen_mangle_unused_area() PRODUCT_RETURN;
274 // Call these in sequential code around the processing of strong roots.
275 class ParStrongRootsScope : public MarkingCodeBlobClosure::MarkScope {
276 public:
277 ParStrongRootsScope();
278 ~ParStrongRootsScope();
279 };
280 };
282 inline size_t ParallelScavengeHeap::set_alignment(size_t& var, size_t val)
283 {
284 assert(is_power_of_2((intptr_t)val), "must be a power of 2");
285 var = round_to(val, intra_heap_alignment());
286 return var;
287 }
289 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARALLELSCAVENGEHEAP_HPP