annotate src/share/vm/gc_implementation/g1/concurrentG1Refine.hpp @ 1111:44f61c24ddab

6862387: tune concurrent refinement further Summary: Reworked the concurrent refinement: threads activation, feedback-based threshold adjustment, other miscellaneous fixes. Reviewed-by: apetrusenko, tonyp
author iveresov
date Wed, 16 Dec 2009 15:12:51 -0800
parents 035d2e036a9b
children b81f3572f355
rev   line source
ysr@342 1 /*
xdono@579 2 * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
ysr@342 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@342 4 *
ysr@342 5 * This code is free software; you can redistribute it and/or modify it
ysr@342 6 * under the terms of the GNU General Public License version 2 only, as
ysr@342 7 * published by the Free Software Foundation.
ysr@342 8 *
ysr@342 9 * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@342 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@342 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
ysr@342 12 * version 2 for more details (a copy is included in the LICENSE file that
ysr@342 13 * accompanied this code).
ysr@342 14 *
ysr@342 15 * You should have received a copy of the GNU General Public License version
ysr@342 16 * 2 along with this work; if not, write to the Free Software Foundation,
ysr@342 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@342 18 *
ysr@342 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
ysr@342 20 * CA 95054 USA or visit www.sun.com if you need additional information or
ysr@342 21 * have any questions.
ysr@342 22 *
ysr@342 23 */
ysr@342 24
ysr@342 25 // Forward decl
ysr@342 26 class ConcurrentG1RefineThread;
ysr@342 27 class G1RemSet;
ysr@342 28
apetrusenko@549 29 class ConcurrentG1Refine: public CHeapObj {
iveresov@794 30 ConcurrentG1RefineThread** _threads;
iveresov@794 31 int _n_threads;
iveresov@1111 32 int _n_worker_threads;
iveresov@1111 33 /*
iveresov@1111 34 * The value of the update buffer queue length falls into one of 3 zones:
iveresov@1111 35 * green, yellow, red. If the value is in [0, green) nothing is
iveresov@1111 36 * done, the buffers are left unprocessed to enable the caching effect of the
iveresov@1111 37 * dirtied cards. In the yellow zone [green, yellow) the concurrent refinement
iveresov@1111 38 * threads are gradually activated. In [yellow, red) all threads are
iveresov@1111 39 * running. If the length becomes red (max queue length) the mutators start
iveresov@1111 40 * processing the buffers.
iveresov@1111 41 *
iveresov@1111 42 * There are some interesting cases (with G1AdaptiveConcRefine turned off):
iveresov@1111 43 * 1) green = yellow = red = 0. In this case the mutator will process all
iveresov@1111 44 * buffers. Except for those that are created by the deferred updates
iveresov@1111 45 * machinery during a collection.
iveresov@1111 46 * 2) green = 0. Means no caching. Can be a good way to minimize the
iveresov@1111 47 * amount of time spent updating rsets during a collection.
iveresov@1111 48 */
iveresov@1111 49 int _green_zone;
iveresov@1111 50 int _yellow_zone;
iveresov@1111 51 int _red_zone;
iveresov@1111 52
iveresov@1111 53 int _thread_threshold_step;
iveresov@1111 54
iveresov@1111 55 // Reset the threshold step value based of the current zone boundaries.
iveresov@1111 56 void reset_threshold_step();
johnc@890 57
ysr@342 58 // The cache for card refinement.
johnc@890 59 bool _use_cache;
johnc@890 60 bool _def_use_cache;
ysr@342 61
johnc@890 62 size_t _n_periods; // Used as clearing epoch
johnc@890 63
johnc@890 64 // An evicting cache of the number of times each card
johnc@890 65 // is accessed. Reduces, but does not eliminate, the amount
johnc@890 66 // of duplicated processing of dirty cards.
johnc@890 67
johnc@890 68 enum SomePrivateConstants {
johnc@890 69 epoch_bits = 32,
johnc@890 70 card_num_shift = epoch_bits,
johnc@890 71 epoch_mask = AllBits,
johnc@890 72 card_num_mask = AllBits,
johnc@890 73
johnc@890 74 // The initial cache size is approximately this fraction
johnc@890 75 // of a maximal cache (i.e. the size needed for all cards
johnc@890 76 // in the heap)
johnc@890 77 InitialCacheFraction = 512
johnc@890 78 };
johnc@890 79
johnc@890 80 const static julong card_num_mask_in_place =
johnc@890 81 (julong) card_num_mask << card_num_shift;
johnc@890 82
johnc@890 83 typedef struct {
johnc@890 84 julong _value; // | card_num | epoch |
johnc@890 85 } CardEpochCacheEntry;
johnc@890 86
johnc@890 87 julong make_epoch_entry(unsigned int card_num, unsigned int epoch) {
johnc@890 88 assert(0 <= card_num && card_num < _max_n_card_counts, "Bounds");
johnc@890 89 assert(0 <= epoch && epoch <= _n_periods, "must be");
johnc@890 90
johnc@890 91 return ((julong) card_num << card_num_shift) | epoch;
johnc@890 92 }
johnc@890 93
johnc@890 94 unsigned int extract_epoch(julong v) {
johnc@890 95 return (v & epoch_mask);
johnc@890 96 }
johnc@890 97
johnc@890 98 unsigned int extract_card_num(julong v) {
johnc@890 99 return (v & card_num_mask_in_place) >> card_num_shift;
johnc@890 100 }
johnc@890 101
johnc@890 102 typedef struct {
johnc@890 103 unsigned char _count;
johnc@890 104 unsigned char _evict_count;
johnc@890 105 } CardCountCacheEntry;
johnc@890 106
johnc@890 107 CardCountCacheEntry* _card_counts;
johnc@890 108 CardEpochCacheEntry* _card_epochs;
johnc@890 109
johnc@890 110 // The current number of buckets in the card count cache
johnc@890 111 unsigned _n_card_counts;
johnc@890 112
johnc@890 113 // The max number of buckets required for the number of
johnc@890 114 // cards for the entire reserved heap
johnc@890 115 unsigned _max_n_card_counts;
johnc@890 116
johnc@890 117 // Possible sizes of the cache: odd primes that roughly double in size.
johnc@890 118 // (See jvmtiTagMap.cpp).
johnc@890 119 static int _cc_cache_sizes[];
johnc@890 120
johnc@890 121 // The index in _cc_cache_sizes corresponding to the size of
johnc@890 122 // _card_counts.
johnc@890 123 int _cache_size_index;
johnc@890 124
johnc@890 125 bool _expand_card_counts;
johnc@890 126
johnc@890 127 const jbyte* _ct_bot;
johnc@889 128
johnc@889 129 jbyte** _hot_cache;
johnc@889 130 int _hot_cache_size;
johnc@889 131 int _n_hot;
johnc@889 132 int _hot_cache_idx;
johnc@889 133
johnc@889 134 int _hot_cache_par_chunk_size;
johnc@889 135 volatile int _hot_cache_par_claimed_idx;
ysr@342 136
johnc@890 137 // Needed to workaround 6817995
johnc@890 138 CardTableModRefBS* _ct_bs;
johnc@890 139 G1CollectedHeap* _g1h;
johnc@890 140
johnc@890 141 // Expands the array that holds the card counts to the next size up
johnc@890 142 void expand_card_count_cache();
johnc@890 143
johnc@890 144 // hash a given key (index of card_ptr) with the specified size
johnc@890 145 static unsigned int hash(size_t key, int size) {
johnc@890 146 return (unsigned int) key % size;
johnc@890 147 }
johnc@890 148
johnc@890 149 // hash a given key (index of card_ptr)
johnc@890 150 unsigned int hash(size_t key) {
johnc@890 151 return hash(key, _n_card_counts);
johnc@890 152 }
johnc@890 153
johnc@890 154 unsigned ptr_2_card_num(jbyte* card_ptr) {
johnc@890 155 return (unsigned) (card_ptr - _ct_bot);
johnc@890 156 }
johnc@890 157
johnc@890 158 jbyte* card_num_2_ptr(unsigned card_num) {
johnc@890 159 return (jbyte*) (_ct_bot + card_num);
johnc@890 160 }
johnc@890 161
ysr@342 162 // Returns the count of this card after incrementing it.
johnc@890 163 jbyte* add_card_count(jbyte* card_ptr, int* count, bool* defer);
ysr@342 164
johnc@890 165 // Returns true if this card is in a young region
johnc@890 166 bool is_young_card(jbyte* card_ptr);
johnc@890 167
ysr@342 168 public:
ysr@342 169 ConcurrentG1Refine();
ysr@342 170 ~ConcurrentG1Refine();
ysr@342 171
ysr@342 172 void init(); // Accomplish some initialization that has to wait.
iveresov@794 173 void stop();
ysr@342 174
iveresov@1111 175 void reinitialize_threads();
iveresov@1111 176
iveresov@794 177 // Iterate over the conc refine threads
iveresov@794 178 void threads_do(ThreadClosure *tc);
ysr@342 179
ysr@342 180 // If this is the first entry for the slot, writes into the cache and
ysr@342 181 // returns NULL. If it causes an eviction, returns the evicted pointer.
ysr@342 182 // Otherwise, its a cache hit, and returns NULL.
johnc@890 183 jbyte* cache_insert(jbyte* card_ptr, bool* defer);
ysr@342 184
ysr@342 185 // Process the cached entries.
ysr@342 186 void clean_up_cache(int worker_i, G1RemSet* g1rs);
ysr@342 187
johnc@889 188 // Set up for parallel processing of the cards in the hot cache
johnc@889 189 void clear_hot_cache_claimed_index() {
johnc@889 190 _hot_cache_par_claimed_idx = 0;
johnc@889 191 }
johnc@889 192
ysr@342 193 // Discard entries in the hot cache.
ysr@342 194 void clear_hot_cache() {
ysr@342 195 _hot_cache_idx = 0; _n_hot = 0;
ysr@342 196 }
ysr@342 197
ysr@342 198 bool hot_cache_is_empty() { return _n_hot == 0; }
ysr@342 199
ysr@342 200 bool use_cache() { return _use_cache; }
ysr@342 201 void set_use_cache(bool b) {
ysr@342 202 if (b) _use_cache = _def_use_cache;
ysr@342 203 else _use_cache = false;
ysr@342 204 }
ysr@342 205
ysr@342 206 void clear_and_record_card_counts();
iveresov@795 207
iveresov@1111 208 static int thread_num();
tonyp@1019 209
tonyp@1019 210 void print_worker_threads_on(outputStream* st) const;
iveresov@1111 211
iveresov@1111 212 void set_green_zone(int x) { _green_zone = x; }
iveresov@1111 213 void set_yellow_zone(int x) { _yellow_zone = x; }
iveresov@1111 214 void set_red_zone(int x) { _red_zone = x; }
iveresov@1111 215
iveresov@1111 216 int green_zone() const { return _green_zone; }
iveresov@1111 217 int yellow_zone() const { return _yellow_zone; }
iveresov@1111 218 int red_zone() const { return _red_zone; }
iveresov@1111 219
iveresov@1111 220 int total_thread_num() const { return _n_threads; }
iveresov@1111 221 int worker_thread_num() const { return _n_worker_threads; }
iveresov@1111 222
iveresov@1111 223 int thread_threshold_step() const { return _thread_threshold_step; }
ysr@342 224 };