Thu, 28 Mar 2013 10:27:28 +0100
7014552: gc/lock/jni/jnilockXXX works too slow on 1-processor machine
Summary: Keep a counter of how many times we were stalled by the GC locker, add a diagnostic flag which sets the limit.
Reviewed-by: brutisso, ehelin, johnc
1 /*
2 * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
28 #include "gc_implementation/g1/concurrentMark.hpp"
29 #include "gc_implementation/g1/g1CollectedHeap.hpp"
30 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
31 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
32 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
33 #include "utilities/taskqueue.hpp"
35 // Inline functions for G1CollectedHeap
37 template <class T>
38 inline HeapRegion*
39 G1CollectedHeap::heap_region_containing(const T addr) const {
40 HeapRegion* hr = _hrs.addr_to_region((HeapWord*) addr);
41 // hr can be null if addr in perm_gen
42 if (hr != NULL && hr->continuesHumongous()) {
43 hr = hr->humongous_start_region();
44 }
45 return hr;
46 }
48 template <class T>
49 inline HeapRegion*
50 G1CollectedHeap::heap_region_containing_raw(const T addr) const {
51 assert(_g1_reserved.contains((const void*) addr), "invariant");
52 HeapRegion* res = _hrs.addr_to_region_unsafe((HeapWord*) addr);
53 return res;
54 }
56 inline bool G1CollectedHeap::obj_in_cs(oop obj) {
57 HeapRegion* r = _hrs.addr_to_region((HeapWord*) obj);
58 return r != NULL && r->in_collection_set();
59 }
61 inline HeapWord*
62 G1CollectedHeap::attempt_allocation(size_t word_size,
63 unsigned int* gc_count_before_ret,
64 int* gclocker_retry_count_ret) {
65 assert_heap_not_locked_and_not_at_safepoint();
66 assert(!isHumongous(word_size), "attempt_allocation() should not "
67 "be called for humongous allocation requests");
69 HeapWord* result = _mutator_alloc_region.attempt_allocation(word_size,
70 false /* bot_updates */);
71 if (result == NULL) {
72 result = attempt_allocation_slow(word_size,
73 gc_count_before_ret,
74 gclocker_retry_count_ret);
75 }
76 assert_heap_not_locked();
77 if (result != NULL) {
78 dirty_young_block(result, word_size);
79 }
80 return result;
81 }
83 inline HeapWord* G1CollectedHeap::survivor_attempt_allocation(size_t
84 word_size) {
85 assert(!isHumongous(word_size),
86 "we should not be seeing humongous-size allocations in this path");
88 HeapWord* result = _survivor_gc_alloc_region.attempt_allocation(word_size,
89 false /* bot_updates */);
90 if (result == NULL) {
91 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
92 result = _survivor_gc_alloc_region.attempt_allocation_locked(word_size,
93 false /* bot_updates */);
94 }
95 if (result != NULL) {
96 dirty_young_block(result, word_size);
97 }
98 return result;
99 }
101 inline HeapWord* G1CollectedHeap::old_attempt_allocation(size_t word_size) {
102 assert(!isHumongous(word_size),
103 "we should not be seeing humongous-size allocations in this path");
105 HeapWord* result = _old_gc_alloc_region.attempt_allocation(word_size,
106 true /* bot_updates */);
107 if (result == NULL) {
108 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
109 result = _old_gc_alloc_region.attempt_allocation_locked(word_size,
110 true /* bot_updates */);
111 }
112 return result;
113 }
115 // It dirties the cards that cover the block so that so that the post
116 // write barrier never queues anything when updating objects on this
117 // block. It is assumed (and in fact we assert) that the block
118 // belongs to a young region.
119 inline void
120 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
121 assert_heap_not_locked();
123 // Assign the containing region to containing_hr so that we don't
124 // have to keep calling heap_region_containing_raw() in the
125 // asserts below.
126 DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing_raw(start);)
127 assert(containing_hr != NULL && start != NULL && word_size > 0,
128 "pre-condition");
129 assert(containing_hr->is_in(start), "it should contain start");
130 assert(containing_hr->is_young(), "it should be young");
131 assert(!containing_hr->isHumongous(), "it should not be humongous");
133 HeapWord* end = start + word_size;
134 assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
136 MemRegion mr(start, end);
137 ((CardTableModRefBS*)_g1h->barrier_set())->dirty(mr);
138 }
140 inline RefToScanQueue* G1CollectedHeap::task_queue(int i) const {
141 return _task_queues->queue(i);
142 }
144 inline bool G1CollectedHeap::isMarkedPrev(oop obj) const {
145 return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj);
146 }
148 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
149 return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
150 }
152 #ifndef PRODUCT
153 // Support for G1EvacuationFailureALot
155 inline bool
156 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
157 bool during_initial_mark,
158 bool during_marking) {
159 bool res = false;
160 if (during_marking) {
161 res |= G1EvacuationFailureALotDuringConcMark;
162 }
163 if (during_initial_mark) {
164 res |= G1EvacuationFailureALotDuringInitialMark;
165 }
166 if (gcs_are_young) {
167 res |= G1EvacuationFailureALotDuringYoungGC;
168 } else {
169 // GCs are mixed
170 res |= G1EvacuationFailureALotDuringMixedGC;
171 }
172 return res;
173 }
175 inline void
176 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
177 if (G1EvacuationFailureALot) {
178 // Note we can't assert that _evacuation_failure_alot_for_current_gc
179 // is clear here. It may have been set during a previous GC but that GC
180 // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
181 // trigger an evacuation failure and clear the flags and and counts.
183 // Check if we have gone over the interval.
184 const size_t gc_num = total_collections();
185 const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
187 _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
189 // Now check if G1EvacuationFailureALot is enabled for the current GC type.
190 const bool gcs_are_young = g1_policy()->gcs_are_young();
191 const bool during_im = g1_policy()->during_initial_mark_pause();
192 const bool during_marking = mark_in_progress();
194 _evacuation_failure_alot_for_current_gc &=
195 evacuation_failure_alot_for_gc_type(gcs_are_young,
196 during_im,
197 during_marking);
198 }
199 }
201 inline bool
202 G1CollectedHeap::evacuation_should_fail() {
203 if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
204 return false;
205 }
206 // G1EvacuationFailureALot is in effect for current GC
207 // Access to _evacuation_failure_alot_count is not atomic;
208 // the value does not have to be exact.
209 if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
210 return false;
211 }
212 _evacuation_failure_alot_count = 0;
213 return true;
214 }
216 inline void G1CollectedHeap::reset_evacuation_should_fail() {
217 if (G1EvacuationFailureALot) {
218 _evacuation_failure_alot_gc_number = total_collections();
219 _evacuation_failure_alot_count = 0;
220 _evacuation_failure_alot_for_current_gc = false;
221 }
222 }
223 #endif // #ifndef PRODUCT
225 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP