1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/g1/g1CardCounts.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,212 @@
1.4 +/*
1.5 + * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "gc_implementation/g1/g1CardCounts.hpp"
1.30 +#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
1.31 +#include "gc_implementation/g1/g1CollectorPolicy.hpp"
1.32 +#include "gc_implementation/g1/g1GCPhaseTimes.hpp"
1.33 +#include "memory/cardTableModRefBS.hpp"
1.34 +#include "services/memTracker.hpp"
1.35 +#include "utilities/copy.hpp"
1.36 +
1.37 +PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
1.38 +
1.39 +void G1CardCounts::clear_range(size_t from_card_num, size_t to_card_num) {
1.40 + if (has_count_table()) {
1.41 + assert(from_card_num >= 0 && from_card_num < _committed_max_card_num,
1.42 + err_msg("from card num out of range: "SIZE_FORMAT, from_card_num));
1.43 + assert(from_card_num < to_card_num,
1.44 + err_msg("Wrong order? from: " SIZE_FORMAT ", to: "SIZE_FORMAT,
1.45 + from_card_num, to_card_num));
1.46 + assert(to_card_num <= _committed_max_card_num,
1.47 + err_msg("to card num out of range: "
1.48 + "to: "SIZE_FORMAT ", "
1.49 + "max: "SIZE_FORMAT,
1.50 + to_card_num, _committed_max_card_num));
1.51 +
1.52 + to_card_num = MIN2(_committed_max_card_num, to_card_num);
1.53 +
1.54 + Copy::fill_to_bytes(&_card_counts[from_card_num], (to_card_num - from_card_num));
1.55 + }
1.56 +}
1.57 +
1.58 +G1CardCounts::G1CardCounts(G1CollectedHeap *g1h):
1.59 + _g1h(g1h), _card_counts(NULL),
1.60 + _reserved_max_card_num(0), _committed_max_card_num(0),
1.61 + _committed_size(0) {}
1.62 +
1.63 +void G1CardCounts::initialize() {
1.64 + assert(_g1h->max_capacity() > 0, "initialization order");
1.65 + assert(_g1h->capacity() == 0, "initialization order");
1.66 +
1.67 + if (G1ConcRSHotCardLimit > 0) {
1.68 + // The max value we can store in the counts table is
1.69 + // max_jubyte. Guarantee the value of the hot
1.70 + // threshold limit is no more than this.
1.71 + guarantee(G1ConcRSHotCardLimit <= max_jubyte, "sanity");
1.72 +
1.73 + _ct_bs = _g1h->g1_barrier_set();
1.74 + _ct_bot = _ct_bs->byte_for_const(_g1h->reserved_region().start());
1.75 +
1.76 + // Allocate/Reserve the counts table
1.77 + size_t reserved_bytes = _g1h->max_capacity();
1.78 + _reserved_max_card_num = reserved_bytes >> CardTableModRefBS::card_shift;
1.79 +
1.80 + size_t reserved_size = _reserved_max_card_num * sizeof(jbyte);
1.81 + ReservedSpace rs(ReservedSpace::allocation_align_size_up(reserved_size));
1.82 + if (!rs.is_reserved()) {
1.83 + warning("Could not reserve enough space for the card counts table");
1.84 + guarantee(!has_reserved_count_table(), "should be NULL");
1.85 + return;
1.86 + }
1.87 +
1.88 + MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
1.89 +
1.90 + _card_counts_storage.initialize(rs, 0);
1.91 + _card_counts = (jubyte*) _card_counts_storage.low();
1.92 + }
1.93 +}
1.94 +
1.95 +void G1CardCounts::resize(size_t heap_capacity) {
1.96 + // Expand the card counts table to handle a heap with the given capacity.
1.97 +
1.98 + if (!has_reserved_count_table()) {
1.99 + // Don't expand if we failed to reserve the card counts table.
1.100 + return;
1.101 + }
1.102 +
1.103 + assert(_committed_size ==
1.104 + ReservedSpace::allocation_align_size_up(_committed_size),
1.105 + err_msg("Unaligned? committed_size: " SIZE_FORMAT, _committed_size));
1.106 +
1.107 + // Verify that the committed space for the card counts matches our
1.108 + // committed max card num. Note for some allocation alignments, the
1.109 + // amount of space actually committed for the counts table will be able
1.110 + // to span more cards than the number spanned by the maximum heap.
1.111 + size_t prev_committed_size = _committed_size;
1.112 + size_t prev_committed_card_num = committed_to_card_num(prev_committed_size);
1.113 +
1.114 + assert(prev_committed_card_num == _committed_max_card_num,
1.115 + err_msg("Card mismatch: "
1.116 + "prev: " SIZE_FORMAT ", "
1.117 + "committed: "SIZE_FORMAT", "
1.118 + "reserved: "SIZE_FORMAT,
1.119 + prev_committed_card_num, _committed_max_card_num, _reserved_max_card_num));
1.120 +
1.121 + size_t new_size = (heap_capacity >> CardTableModRefBS::card_shift) * sizeof(jbyte);
1.122 + size_t new_committed_size = ReservedSpace::allocation_align_size_up(new_size);
1.123 + size_t new_committed_card_num = committed_to_card_num(new_committed_size);
1.124 +
1.125 + if (_committed_max_card_num < new_committed_card_num) {
1.126 + // we need to expand the backing store for the card counts
1.127 + size_t expand_size = new_committed_size - prev_committed_size;
1.128 +
1.129 + if (!_card_counts_storage.expand_by(expand_size)) {
1.130 + warning("Card counts table backing store commit failure");
1.131 + return;
1.132 + }
1.133 + assert(_card_counts_storage.committed_size() == new_committed_size,
1.134 + "expansion commit failure");
1.135 +
1.136 + _committed_size = new_committed_size;
1.137 + _committed_max_card_num = new_committed_card_num;
1.138 +
1.139 + clear_range(prev_committed_card_num, _committed_max_card_num);
1.140 + }
1.141 +}
1.142 +
1.143 +uint G1CardCounts::add_card_count(jbyte* card_ptr) {
1.144 + // Returns the number of times the card has been refined.
1.145 + // If we failed to reserve/commit the counts table, return 0.
1.146 + // If card_ptr is beyond the committed end of the counts table,
1.147 + // return 0.
1.148 + // Otherwise return the actual count.
1.149 + // Unless G1ConcRSHotCardLimit has been set appropriately,
1.150 + // returning 0 will result in the card being considered
1.151 + // cold and will be refined immediately.
1.152 + uint count = 0;
1.153 + if (has_count_table()) {
1.154 + size_t card_num = ptr_2_card_num(card_ptr);
1.155 + if (card_num < _committed_max_card_num) {
1.156 + count = (uint) _card_counts[card_num];
1.157 + if (count < G1ConcRSHotCardLimit) {
1.158 + _card_counts[card_num] =
1.159 + (jubyte)(MIN2((uintx)(_card_counts[card_num] + 1), G1ConcRSHotCardLimit));
1.160 + }
1.161 + }
1.162 + }
1.163 + return count;
1.164 +}
1.165 +
1.166 +bool G1CardCounts::is_hot(uint count) {
1.167 + return (count >= G1ConcRSHotCardLimit);
1.168 +}
1.169 +
1.170 +void G1CardCounts::clear_region(HeapRegion* hr) {
1.171 + assert(!hr->isHumongous(), "Should have been cleared");
1.172 + if (has_count_table()) {
1.173 + HeapWord* bottom = hr->bottom();
1.174 +
1.175 + // We use the last address in hr as hr could be the
1.176 + // last region in the heap. In which case trying to find
1.177 + // the card for hr->end() will be an OOB accesss to the
1.178 + // card table.
1.179 + HeapWord* last = hr->end() - 1;
1.180 + assert(_g1h->g1_committed().contains(last),
1.181 + err_msg("last not in committed: "
1.182 + "last: " PTR_FORMAT ", "
1.183 + "committed: [" PTR_FORMAT ", " PTR_FORMAT ")",
1.184 + last,
1.185 + _g1h->g1_committed().start(),
1.186 + _g1h->g1_committed().end()));
1.187 +
1.188 + const jbyte* from_card_ptr = _ct_bs->byte_for_const(bottom);
1.189 + const jbyte* last_card_ptr = _ct_bs->byte_for_const(last);
1.190 +
1.191 +#ifdef ASSERT
1.192 + HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);
1.193 + assert(start_addr == hr->bottom(), "alignment");
1.194 + HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr);
1.195 + assert((last_addr + CardTableModRefBS::card_size_in_words) == hr->end(), "alignment");
1.196 +#endif // ASSERT
1.197 +
1.198 + // Clear the counts for the (exclusive) card range.
1.199 + size_t from_card_num = ptr_2_card_num(from_card_ptr);
1.200 + size_t to_card_num = ptr_2_card_num(last_card_ptr) + 1;
1.201 + clear_range(from_card_num, to_card_num);
1.202 + }
1.203 +}
1.204 +
1.205 +void G1CardCounts::clear_all() {
1.206 + assert(SafepointSynchronize::is_at_safepoint(), "don't call this otherwise");
1.207 + clear_range((size_t)0, _committed_max_card_num);
1.208 +}
1.209 +
1.210 +G1CardCounts::~G1CardCounts() {
1.211 + if (has_reserved_count_table()) {
1.212 + _card_counts_storage.release();
1.213 + }
1.214 +}
1.215 +
