Tue, 26 Jan 2010 16:52:29 -0800
6920090: G1: Disable ReduceInitialCardMarks at least until 6920109 is fixed
Summary: G1 now answers "no" to the query can_elide_initializing_store_barrier() in the product build. A debug flag allows alternate behaviour in debug builds.
Reviewed-by: iveresov, tonyp
ysr@777 | 1 | /* |
xdono@1014 | 2 | * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved. |
ysr@777 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
ysr@777 | 4 | * |
ysr@777 | 5 | * This code is free software; you can redistribute it and/or modify it |
ysr@777 | 6 | * under the terms of the GNU General Public License version 2 only, as |
ysr@777 | 7 | * published by the Free Software Foundation. |
ysr@777 | 8 | * |
ysr@777 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
ysr@777 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
ysr@777 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
ysr@777 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
ysr@777 | 13 | * accompanied this code). |
ysr@777 | 14 | * |
ysr@777 | 15 | * You should have received a copy of the GNU General Public License version |
ysr@777 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
ysr@777 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
ysr@777 | 18 | * |
ysr@777 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
ysr@777 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
ysr@777 | 21 | * have any questions. |
ysr@777 | 22 | * |
ysr@777 | 23 | */ |
ysr@777 | 24 | |
ysr@777 | 25 | // Forward decl |
ysr@777 | 26 | class ConcurrentG1RefineThread; |
ysr@777 | 27 | class G1RemSet; |
ysr@777 | 28 | |
apetrusenko@984 | 29 | class ConcurrentG1Refine: public CHeapObj { |
iveresov@1229 | 30 | ConcurrentG1RefineThread** _threads; |
iveresov@1229 | 31 | int _n_threads; |
iveresov@1546 | 32 | int _n_worker_threads; |
iveresov@1546 | 33 | /* |
iveresov@1546 | 34 | * The value of the update buffer queue length falls into one of 3 zones: |
iveresov@1546 | 35 | * green, yellow, red. If the value is in [0, green) nothing is |
iveresov@1546 | 36 | * done, the buffers are left unprocessed to enable the caching effect of the |
iveresov@1546 | 37 | * dirtied cards. In the yellow zone [green, yellow) the concurrent refinement |
iveresov@1546 | 38 | * threads are gradually activated. In [yellow, red) all threads are |
iveresov@1546 | 39 | * running. If the length becomes red (max queue length) the mutators start |
iveresov@1546 | 40 | * processing the buffers. |
iveresov@1546 | 41 | * |
iveresov@1546 | 42 | * There are some interesting cases (with G1AdaptiveConcRefine turned off): |
iveresov@1546 | 43 | * 1) green = yellow = red = 0. In this case the mutator will process all |
iveresov@1546 | 44 | * buffers. Except for those that are created by the deferred updates |
iveresov@1546 | 45 | * machinery during a collection. |
iveresov@1546 | 46 | * 2) green = 0. Means no caching. Can be a good way to minimize the |
iveresov@1546 | 47 | * amount of time spent updating rsets during a collection. |
iveresov@1546 | 48 | */ |
iveresov@1546 | 49 | int _green_zone; |
iveresov@1546 | 50 | int _yellow_zone; |
iveresov@1546 | 51 | int _red_zone; |
iveresov@1546 | 52 | |
iveresov@1546 | 53 | int _thread_threshold_step; |
iveresov@1546 | 54 | |
iveresov@1546 | 55 | // Reset the threshold step value based of the current zone boundaries. |
iveresov@1546 | 56 | void reset_threshold_step(); |
johnc@1325 | 57 | |
ysr@777 | 58 | // The cache for card refinement. |
johnc@1325 | 59 | bool _use_cache; |
johnc@1325 | 60 | bool _def_use_cache; |
ysr@777 | 61 | |
johnc@1325 | 62 | size_t _n_periods; // Used as clearing epoch |
johnc@1325 | 63 | |
johnc@1325 | 64 | // An evicting cache of the number of times each card |
johnc@1325 | 65 | // is accessed. Reduces, but does not eliminate, the amount |
johnc@1325 | 66 | // of duplicated processing of dirty cards. |
johnc@1325 | 67 | |
johnc@1325 | 68 | enum SomePrivateConstants { |
johnc@1325 | 69 | epoch_bits = 32, |
johnc@1325 | 70 | card_num_shift = epoch_bits, |
johnc@1325 | 71 | epoch_mask = AllBits, |
johnc@1325 | 72 | card_num_mask = AllBits, |
johnc@1325 | 73 | |
johnc@1325 | 74 | // The initial cache size is approximately this fraction |
johnc@1325 | 75 | // of a maximal cache (i.e. the size needed for all cards |
johnc@1325 | 76 | // in the heap) |
johnc@1325 | 77 | InitialCacheFraction = 512 |
johnc@1325 | 78 | }; |
johnc@1325 | 79 | |
johnc@1325 | 80 | const static julong card_num_mask_in_place = |
johnc@1325 | 81 | (julong) card_num_mask << card_num_shift; |
johnc@1325 | 82 | |
johnc@1325 | 83 | typedef struct { |
johnc@1325 | 84 | julong _value; // | card_num | epoch | |
johnc@1325 | 85 | } CardEpochCacheEntry; |
johnc@1325 | 86 | |
johnc@1325 | 87 | julong make_epoch_entry(unsigned int card_num, unsigned int epoch) { |
johnc@1325 | 88 | assert(0 <= card_num && card_num < _max_n_card_counts, "Bounds"); |
johnc@1325 | 89 | assert(0 <= epoch && epoch <= _n_periods, "must be"); |
johnc@1325 | 90 | |
johnc@1325 | 91 | return ((julong) card_num << card_num_shift) | epoch; |
johnc@1325 | 92 | } |
johnc@1325 | 93 | |
johnc@1325 | 94 | unsigned int extract_epoch(julong v) { |
johnc@1325 | 95 | return (v & epoch_mask); |
johnc@1325 | 96 | } |
johnc@1325 | 97 | |
johnc@1325 | 98 | unsigned int extract_card_num(julong v) { |
johnc@1325 | 99 | return (v & card_num_mask_in_place) >> card_num_shift; |
johnc@1325 | 100 | } |
johnc@1325 | 101 | |
johnc@1325 | 102 | typedef struct { |
johnc@1325 | 103 | unsigned char _count; |
johnc@1325 | 104 | unsigned char _evict_count; |
johnc@1325 | 105 | } CardCountCacheEntry; |
johnc@1325 | 106 | |
johnc@1325 | 107 | CardCountCacheEntry* _card_counts; |
johnc@1325 | 108 | CardEpochCacheEntry* _card_epochs; |
johnc@1325 | 109 | |
johnc@1325 | 110 | // The current number of buckets in the card count cache |
johnc@1325 | 111 | unsigned _n_card_counts; |
johnc@1325 | 112 | |
johnc@1325 | 113 | // The max number of buckets required for the number of |
johnc@1325 | 114 | // cards for the entire reserved heap |
johnc@1325 | 115 | unsigned _max_n_card_counts; |
johnc@1325 | 116 | |
johnc@1325 | 117 | // Possible sizes of the cache: odd primes that roughly double in size. |
johnc@1325 | 118 | // (See jvmtiTagMap.cpp). |
johnc@1325 | 119 | static int _cc_cache_sizes[]; |
johnc@1325 | 120 | |
johnc@1325 | 121 | // The index in _cc_cache_sizes corresponding to the size of |
johnc@1325 | 122 | // _card_counts. |
johnc@1325 | 123 | int _cache_size_index; |
johnc@1325 | 124 | |
johnc@1325 | 125 | bool _expand_card_counts; |
johnc@1325 | 126 | |
johnc@1325 | 127 | const jbyte* _ct_bot; |
johnc@1324 | 128 | |
johnc@1324 | 129 | jbyte** _hot_cache; |
johnc@1324 | 130 | int _hot_cache_size; |
johnc@1324 | 131 | int _n_hot; |
johnc@1324 | 132 | int _hot_cache_idx; |
johnc@1324 | 133 | |
johnc@1324 | 134 | int _hot_cache_par_chunk_size; |
johnc@1324 | 135 | volatile int _hot_cache_par_claimed_idx; |
ysr@777 | 136 | |
johnc@1325 | 137 | // Needed to workaround 6817995 |
johnc@1325 | 138 | CardTableModRefBS* _ct_bs; |
johnc@1325 | 139 | G1CollectedHeap* _g1h; |
johnc@1325 | 140 | |
johnc@1325 | 141 | // Expands the array that holds the card counts to the next size up |
johnc@1325 | 142 | void expand_card_count_cache(); |
johnc@1325 | 143 | |
johnc@1325 | 144 | // hash a given key (index of card_ptr) with the specified size |
johnc@1325 | 145 | static unsigned int hash(size_t key, int size) { |
johnc@1325 | 146 | return (unsigned int) key % size; |
johnc@1325 | 147 | } |
johnc@1325 | 148 | |
johnc@1325 | 149 | // hash a given key (index of card_ptr) |
johnc@1325 | 150 | unsigned int hash(size_t key) { |
johnc@1325 | 151 | return hash(key, _n_card_counts); |
johnc@1325 | 152 | } |
johnc@1325 | 153 | |
johnc@1325 | 154 | unsigned ptr_2_card_num(jbyte* card_ptr) { |
johnc@1325 | 155 | return (unsigned) (card_ptr - _ct_bot); |
johnc@1325 | 156 | } |
johnc@1325 | 157 | |
johnc@1325 | 158 | jbyte* card_num_2_ptr(unsigned card_num) { |
johnc@1325 | 159 | return (jbyte*) (_ct_bot + card_num); |
johnc@1325 | 160 | } |
johnc@1325 | 161 | |
ysr@777 | 162 | // Returns the count of this card after incrementing it. |
johnc@1325 | 163 | jbyte* add_card_count(jbyte* card_ptr, int* count, bool* defer); |
ysr@777 | 164 | |
johnc@1325 | 165 | // Returns true if this card is in a young region |
johnc@1325 | 166 | bool is_young_card(jbyte* card_ptr); |
johnc@1325 | 167 | |
ysr@777 | 168 | public: |
ysr@777 | 169 | ConcurrentG1Refine(); |
ysr@777 | 170 | ~ConcurrentG1Refine(); |
ysr@777 | 171 | |
ysr@777 | 172 | void init(); // Accomplish some initialization that has to wait. |
iveresov@1229 | 173 | void stop(); |
ysr@777 | 174 | |
iveresov@1546 | 175 | void reinitialize_threads(); |
iveresov@1546 | 176 | |
iveresov@1229 | 177 | // Iterate over the conc refine threads |
iveresov@1229 | 178 | void threads_do(ThreadClosure *tc); |
ysr@777 | 179 | |
ysr@777 | 180 | // If this is the first entry for the slot, writes into the cache and |
ysr@777 | 181 | // returns NULL. If it causes an eviction, returns the evicted pointer. |
ysr@777 | 182 | // Otherwise, its a cache hit, and returns NULL. |
johnc@1325 | 183 | jbyte* cache_insert(jbyte* card_ptr, bool* defer); |
ysr@777 | 184 | |
ysr@777 | 185 | // Process the cached entries. |
ysr@777 | 186 | void clean_up_cache(int worker_i, G1RemSet* g1rs); |
ysr@777 | 187 | |
johnc@1324 | 188 | // Set up for parallel processing of the cards in the hot cache |
johnc@1324 | 189 | void clear_hot_cache_claimed_index() { |
johnc@1324 | 190 | _hot_cache_par_claimed_idx = 0; |
johnc@1324 | 191 | } |
johnc@1324 | 192 | |
ysr@777 | 193 | // Discard entries in the hot cache. |
ysr@777 | 194 | void clear_hot_cache() { |
ysr@777 | 195 | _hot_cache_idx = 0; _n_hot = 0; |
ysr@777 | 196 | } |
ysr@777 | 197 | |
ysr@777 | 198 | bool hot_cache_is_empty() { return _n_hot == 0; } |
ysr@777 | 199 | |
ysr@777 | 200 | bool use_cache() { return _use_cache; } |
ysr@777 | 201 | void set_use_cache(bool b) { |
ysr@777 | 202 | if (b) _use_cache = _def_use_cache; |
ysr@777 | 203 | else _use_cache = false; |
ysr@777 | 204 | } |
ysr@777 | 205 | |
ysr@777 | 206 | void clear_and_record_card_counts(); |
iveresov@1230 | 207 | |
iveresov@1546 | 208 | static int thread_num(); |
tonyp@1454 | 209 | |
tonyp@1454 | 210 | void print_worker_threads_on(outputStream* st) const; |
iveresov@1546 | 211 | |
iveresov@1546 | 212 | void set_green_zone(int x) { _green_zone = x; } |
iveresov@1546 | 213 | void set_yellow_zone(int x) { _yellow_zone = x; } |
iveresov@1546 | 214 | void set_red_zone(int x) { _red_zone = x; } |
iveresov@1546 | 215 | |
iveresov@1546 | 216 | int green_zone() const { return _green_zone; } |
iveresov@1546 | 217 | int yellow_zone() const { return _yellow_zone; } |
iveresov@1546 | 218 | int red_zone() const { return _red_zone; } |
iveresov@1546 | 219 | |
iveresov@1546 | 220 | int total_thread_num() const { return _n_threads; } |
iveresov@1546 | 221 | int worker_thread_num() const { return _n_worker_threads; } |
iveresov@1546 | 222 | |
iveresov@1546 | 223 | int thread_threshold_step() const { return _thread_threshold_step; } |
ysr@777 | 224 | }; |