Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/g1CardCounts.cpp @ 10246:194f52aa2f23
7176479: G1: JVM crashes on T5-8 system with 1.5 TB heap
Summary: Refactor G1's hot card cache and card counts table into their own files. Simplify the card counts table, including removing the encoding of the card index in each entry. The card counts table now has a 1:1 correspondence with the cards spanned by heap. Space for the card counts table is reserved from virtual memory (rather than C heap) during JVM startup and is committed/expanded when the heap is expanded. Changes were also reviewed-by Vitaly Davidovich.
Reviewed-by: tschatzl, jmasa
author | johnc |
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date | Thu, 09 May 2013 11:16:39 -0700 |
parents | |
children | bed55d125e37 |
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/* * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "gc_implementation/g1/g1CardCounts.hpp" #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" #include "gc_implementation/g1/g1CollectorPolicy.hpp" #include "gc_implementation/g1/g1GCPhaseTimes.hpp" #include "memory/cardTableModRefBS.hpp" #include "services/memTracker.hpp" #include "utilities/copy.hpp" void G1CardCounts::clear_range(size_t from_card_num, size_t to_card_num) { if (has_count_table()) { check_card_num(from_card_num, err_msg("from card num out of range: "SIZE_FORMAT, from_card_num)); assert(from_card_num < to_card_num, err_msg("Wrong order? from: " SIZE_FORMAT ", to: "SIZE_FORMAT, from_card_num, to_card_num)); assert(to_card_num <= _committed_max_card_num, err_msg("to card num out of range: " "to: "SIZE_FORMAT ", " "max: "SIZE_FORMAT, to_card_num, _committed_max_card_num)); to_card_num = MIN2(_committed_max_card_num, to_card_num); Copy::fill_to_bytes(&_card_counts[from_card_num], (to_card_num - from_card_num)); } } G1CardCounts::G1CardCounts(G1CollectedHeap *g1h): _g1h(g1h), _card_counts(NULL), _reserved_max_card_num(0), _committed_max_card_num(0), _committed_size(0) {} void G1CardCounts::initialize() { assert(_g1h->max_capacity() > 0, "initialization order"); assert(_g1h->capacity() == 0, "initialization order"); if (G1ConcRSHotCardLimit > 0) { // The max value we can store in the counts table is // max_jubyte. Guarantee the value of the hot // threshold limit is no more than this. guarantee(G1ConcRSHotCardLimit <= max_jubyte, "sanity"); ModRefBarrierSet* bs = _g1h->mr_bs(); guarantee(bs->is_a(BarrierSet::CardTableModRef), "Precondition"); _ct_bs = (CardTableModRefBS*)bs; _ct_bot = _ct_bs->byte_for_const(_g1h->reserved_region().start()); // Allocate/Reserve the counts table size_t reserved_bytes = _g1h->max_capacity(); _reserved_max_card_num = reserved_bytes >> CardTableModRefBS::card_shift; size_t reserved_size = _reserved_max_card_num * sizeof(jbyte); ReservedSpace rs(ReservedSpace::allocation_align_size_up(reserved_size)); if (!rs.is_reserved()) { warning("Could not reserve enough space for the card counts table"); guarantee(!has_reserved_count_table(), "should be NULL"); return; } MemTracker::record_virtual_memory_type((address)rs.base(), mtGC); _card_counts_storage.initialize(rs, 0); _card_counts = (jubyte*) _card_counts_storage.low(); } } void G1CardCounts::resize(size_t heap_capacity) { // Expand the card counts table to handle a heap with the given capacity. if (!has_reserved_count_table()) { // Don't expand if we failed to reserve the card counts table. return; } assert(_committed_size == ReservedSpace::allocation_align_size_up(_committed_size), err_msg("Unaligned? committed_size: " SIZE_FORMAT, _committed_size)); // Verify that the committed space for the card counts // matches our committed max card num. size_t prev_committed_size = _committed_size; size_t prev_committed_card_num = prev_committed_size / sizeof(jbyte); assert(prev_committed_card_num == _committed_max_card_num, err_msg("Card mismatch: " "prev: " SIZE_FORMAT ", " "committed: "SIZE_FORMAT, prev_committed_card_num, _committed_max_card_num)); size_t new_size = (heap_capacity >> CardTableModRefBS::card_shift) * sizeof(jbyte); size_t new_committed_size = ReservedSpace::allocation_align_size_up(new_size); size_t new_committed_card_num = MIN2(_reserved_max_card_num, new_committed_size / sizeof(jbyte)); if (_committed_max_card_num < new_committed_card_num) { // we need to expand the backing store for the card counts size_t expand_size = new_committed_size - prev_committed_size; if (!_card_counts_storage.expand_by(expand_size)) { warning("Card counts table backing store commit failure"); return; } assert(_card_counts_storage.committed_size() == new_committed_size, "expansion commit failure"); _committed_size = new_committed_size; _committed_max_card_num = new_committed_card_num; clear_range(prev_committed_card_num, _committed_max_card_num); } } uint G1CardCounts::add_card_count(jbyte* card_ptr) { // Returns the number of times the card has been refined. // If we failed to reserve/commit the counts table, return 0. // If card_ptr is beyond the committed end of the counts table, // return 0. // Otherwise return the actual count. // Unless G1ConcRSHotCardLimit has been set appropriately, // returning 0 will result in the card being considered // cold and will be refined immediately. uint count = 0; if (has_count_table()) { size_t card_num = ptr_2_card_num(card_ptr); if (card_num < _committed_max_card_num) { count = (uint) _card_counts[card_num]; if (count < G1ConcRSHotCardLimit) { _card_counts[card_num] += 1; } assert(_card_counts[card_num] <= G1ConcRSHotCardLimit, err_msg("Refinement count overflow? " "new count: "UINT32_FORMAT, (uint) _card_counts[card_num])); } } return count; } bool G1CardCounts::is_hot(uint count) { return (count >= G1ConcRSHotCardLimit); } void G1CardCounts::clear_region(HeapRegion* hr) { assert(!hr->isHumongous(), "Should have been cleared"); if (has_count_table()) { HeapWord* bottom = hr->bottom(); // We use the last address in hr as hr could be the // last region in the heap. In which case trying to find // the card for hr->end() will be an OOB accesss to the // card table. HeapWord* last = hr->end() - 1; assert(_g1h->g1_committed().contains(last), err_msg("last not in committed: " "last: " PTR_FORMAT ", " "committed: [" PTR_FORMAT ", " PTR_FORMAT ")", last, _g1h->g1_committed().start(), _g1h->g1_committed().end())); const jbyte* from_card_ptr = _ct_bs->byte_for_const(bottom); const jbyte* last_card_ptr = _ct_bs->byte_for_const(last); #ifdef ASSERT HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr); assert(start_addr == hr->bottom(), "alignment"); HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr); assert((last_addr + CardTableModRefBS::card_size_in_words) == hr->end(), "alignment"); #endif // ASSERT // Clear the counts for the (exclusive) card range. size_t from_card_num = ptr_2_card_num(from_card_ptr); size_t to_card_num = ptr_2_card_num(last_card_ptr) + 1; clear_range(from_card_num, to_card_num); } } void G1CardCounts::clear_all() { assert(SafepointSynchronize::is_at_safepoint(), "don't call this otherwise"); clear_range((size_t)0, _committed_max_card_num); } G1CardCounts::~G1CardCounts() { if (has_reserved_count_table()) { _card_counts_storage.release(); } }