1 /*
2 * Copyright (c) 2013, 2015, 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 *
50 // first is_dirty check in the write barrier, skipping the remainder
51 // of the write barrier.
52 //
53 // This can significantly reduce the overhead of the write barrier
54 // code, increasing throughput.
55
56 class G1HotCardCache: public CHeapObj<mtGC> {
57
58 G1CollectedHeap* _g1h;
59
60 bool _use_cache;
61
62 G1CardCounts _card_counts;
63
64
65 // The card cache table
66 jbyte** _hot_cache;
67
68 size_t _hot_cache_size;
69
70 int _hot_cache_par_chunk_size;
71
72 // Avoids false sharing when concurrently updating _hot_cache_idx or
73 // _hot_cache_par_claimed_idx. These are never updated at the same time
74 // thus it's not necessary to separate them as well
75 char _pad_before[DEFAULT_CACHE_LINE_SIZE];
76
77 volatile size_t _hot_cache_idx;
78
79 volatile size_t _hot_cache_par_claimed_idx;
80
81 char _pad_after[DEFAULT_CACHE_LINE_SIZE];
82
83 // The number of cached cards a thread claims when flushing the cache
84 static const int ClaimChunkSize = 32;
85
86 public:
87 static bool default_use_cache() {
88 return (G1ConcRSLogCacheSize > 0);
89 }
90
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1 /*
2 * Copyright (c) 2013, 2017, 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 *
50 // first is_dirty check in the write barrier, skipping the remainder
51 // of the write barrier.
52 //
53 // This can significantly reduce the overhead of the write barrier
54 // code, increasing throughput.
55
56 class G1HotCardCache: public CHeapObj<mtGC> {
57
58 G1CollectedHeap* _g1h;
59
60 bool _use_cache;
61
62 G1CardCounts _card_counts;
63
64
65 // The card cache table
66 jbyte** _hot_cache;
67
68 size_t _hot_cache_size;
69
70 size_t _hot_cache_par_chunk_size;
71
72 // Avoids false sharing when concurrently updating _hot_cache_idx or
73 // _hot_cache_par_claimed_idx. These are never updated at the same time
74 // thus it's not necessary to separate them as well
75 char _pad_before[DEFAULT_CACHE_LINE_SIZE];
76
77 volatile size_t _hot_cache_idx;
78
79 volatile size_t _hot_cache_par_claimed_idx;
80
81 char _pad_after[DEFAULT_CACHE_LINE_SIZE];
82
83 // The number of cached cards a thread claims when flushing the cache
84 static const int ClaimChunkSize = 32;
85
86 public:
87 static bool default_use_cache() {
88 return (G1ConcRSLogCacheSize > 0);
89 }
90
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