Mercurial > hg > graal-compiler
annotate src/share/vm/oops/markOop.inline.hpp @ 1711:a6bff45449bc
6973570: OrderAccess::storestore() scales poorly on multi-socket x64 and sparc: cache-line ping-ponging
Summary: volatile store to static variable removed in favour of a volatile store to stack to avoid excessive cache coherency traffic; verified that the volatile store is not elided by any of our current compilers.
Reviewed-by: dholmes, dice, jcoomes, kvn
author | ysr |
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date | Tue, 10 Aug 2010 14:53:35 -0700 |
parents | c18cbe5936b8 |
children | f95d63e2154a |
rev | line source |
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0 | 1 /* |
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2 * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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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). | |
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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, | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
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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 | |
25 // Should this header be preserved during GC? | |
26 inline bool markOopDesc::must_be_preserved_with_bias(oop obj_containing_mark) const { | |
27 assert(UseBiasedLocking, "unexpected"); | |
28 if (has_bias_pattern()) { | |
29 // Will reset bias at end of collection | |
30 // Mark words of biased and currently locked objects are preserved separately | |
31 return false; | |
32 } | |
33 markOop prototype_header = prototype_for_object(obj_containing_mark); | |
34 if (prototype_header->has_bias_pattern()) { | |
35 // Individual instance which has its bias revoked; must return | |
36 // true for correctness | |
37 return true; | |
38 } | |
39 return (!is_unlocked() || !has_no_hash()); | |
40 } | |
41 | |
342 | 42 inline bool markOopDesc::must_be_preserved(oop obj_containing_mark) const { |
43 if (!UseBiasedLocking) | |
44 return (!is_unlocked() || !has_no_hash()); | |
45 return must_be_preserved_with_bias(obj_containing_mark); | |
46 } | |
47 | |
0 | 48 // Should this header (including its age bits) be preserved in the |
49 // case of a promotion failure during scavenge? | |
50 inline bool markOopDesc::must_be_preserved_with_bias_for_promotion_failure(oop obj_containing_mark) const { | |
51 assert(UseBiasedLocking, "unexpected"); | |
52 // We don't explicitly save off the mark words of biased and | |
53 // currently-locked objects during scavenges, so if during a | |
54 // promotion failure we encounter either a biased mark word or a | |
55 // klass which still has a biasable prototype header, we have to | |
56 // preserve the mark word. This results in oversaving, but promotion | |
57 // failures are rare, and this avoids adding more complex logic to | |
58 // the scavengers to call new variants of | |
59 // BiasedLocking::preserve_marks() / restore_marks() in the middle | |
60 // of a scavenge when a promotion failure has first been detected. | |
61 if (has_bias_pattern() || | |
62 prototype_for_object(obj_containing_mark)->has_bias_pattern()) { | |
63 return true; | |
64 } | |
65 return (this != prototype()); | |
66 } | |
67 | |
342 | 68 inline bool markOopDesc::must_be_preserved_for_promotion_failure(oop obj_containing_mark) const { |
69 if (!UseBiasedLocking) | |
70 return (this != prototype()); | |
71 return must_be_preserved_with_bias_for_promotion_failure(obj_containing_mark); | |
72 } | |
73 | |
74 | |
0 | 75 // Should this header (including its age bits) be preserved in the |
76 // case of a scavenge in which CMS is the old generation? | |
77 inline bool markOopDesc::must_be_preserved_with_bias_for_cms_scavenge(klassOop klass_of_obj_containing_mark) const { | |
78 assert(UseBiasedLocking, "unexpected"); | |
79 // CMS scavenges preserve mark words in similar fashion to promotion failures; see above | |
80 if (has_bias_pattern() || | |
81 klass_of_obj_containing_mark->klass_part()->prototype_header()->has_bias_pattern()) { | |
82 return true; | |
83 } | |
84 return (this != prototype()); | |
85 } | |
342 | 86 inline bool markOopDesc::must_be_preserved_for_cms_scavenge(klassOop klass_of_obj_containing_mark) const { |
87 if (!UseBiasedLocking) | |
88 return (this != prototype()); | |
89 return must_be_preserved_with_bias_for_cms_scavenge(klass_of_obj_containing_mark); | |
90 } | |
0 | 91 |
92 inline markOop markOopDesc::prototype_for_object(oop obj) { | |
93 #ifdef ASSERT | |
94 markOop prototype_header = obj->klass()->klass_part()->prototype_header(); | |
95 assert(prototype_header == prototype() || prototype_header->has_bias_pattern(), "corrupt prototype header"); | |
96 #endif | |
97 return obj->klass()->klass_part()->prototype_header(); | |
98 } |