Mercurial > hg > truffle
diff src/share/vm/gc_implementation/g1/g1RegionToSpaceMapper.cpp @ 20337:1f1d373cd044
8038423: G1: Decommit memory within heap
Summary: Allow G1 to decommit memory of arbitrary regions within the heap and their associated auxiliary data structures card table, BOT, hot card cache, and mark bitmaps.
Reviewed-by: mgerdin, brutisso, jwilhelm
author | tschatzl |
---|---|
date | Thu, 21 Aug 2014 11:47:10 +0200 |
parents | |
children | 7b2fc3129653 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/g1/g1RegionToSpaceMapper.cpp Thu Aug 21 11:47:10 2014 +0200 @@ -0,0 +1,158 @@ +/* + * Copyright (c) 2001, 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/g1BiasedArray.hpp" +#include "gc_implementation/g1/g1RegionToSpaceMapper.hpp" +#include "runtime/virtualspace.hpp" +#include "services/memTracker.hpp" +#include "utilities/bitMap.inline.hpp" + +G1RegionToSpaceMapper::G1RegionToSpaceMapper(ReservedSpace rs, + size_t commit_granularity, + size_t region_granularity, + MemoryType type) : + _storage(), + _commit_granularity(commit_granularity), + _region_granularity(region_granularity), + _listener(NULL), + _commit_map() { + guarantee(is_power_of_2(commit_granularity), "must be"); + guarantee(is_power_of_2(region_granularity), "must be"); + _storage.initialize_with_granularity(rs, commit_granularity); + + MemTracker::record_virtual_memory_type((address)rs.base(), type); +} + +// G1RegionToSpaceMapper implementation where the region granularity is larger than +// or the same as the commit granularity. +// Basically, the space corresponding to one region region spans several OS pages. +class G1RegionsLargerThanCommitSizeMapper : public G1RegionToSpaceMapper { + private: + size_t _pages_per_region; + + public: + G1RegionsLargerThanCommitSizeMapper(ReservedSpace rs, + size_t os_commit_granularity, + size_t alloc_granularity, + size_t commit_factor, + MemoryType type) : + G1RegionToSpaceMapper(rs, os_commit_granularity, alloc_granularity, type), + _pages_per_region(alloc_granularity / (os_commit_granularity * commit_factor)) { + + guarantee(alloc_granularity >= os_commit_granularity, "allocation granularity smaller than commit granularity"); + _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false); + } + + virtual void commit_regions(uintptr_t start_idx, size_t num_regions) { + _storage.commit(start_idx * _pages_per_region, num_regions * _pages_per_region); + _commit_map.set_range(start_idx, start_idx + num_regions); + fire_on_commit(start_idx, num_regions); + } + + virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions) { + _storage.uncommit(start_idx * _pages_per_region, num_regions * _pages_per_region); + _commit_map.clear_range(start_idx, start_idx + num_regions); + } +}; + +// G1RegionToSpaceMapper implementation where the region granularity is smaller +// than the commit granularity. +// Basically, the contents of one OS page span several regions. +class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper { + private: + class CommitRefcountArray : public G1BiasedMappedArray<uint> { + protected: + virtual uint default_value() const { return 0; } + }; + + size_t _regions_per_page; + + CommitRefcountArray _refcounts; + + uintptr_t region_idx_to_page_idx(uint region) const { + return region / _regions_per_page; + } + + public: + G1RegionsSmallerThanCommitSizeMapper(ReservedSpace rs, + size_t os_commit_granularity, + size_t alloc_granularity, + size_t commit_factor, + MemoryType type) : + G1RegionToSpaceMapper(rs, os_commit_granularity, alloc_granularity, type), + _regions_per_page((os_commit_granularity * commit_factor) / alloc_granularity), _refcounts() { + + guarantee((os_commit_granularity * commit_factor) >= alloc_granularity, "allocation granularity smaller than commit granularity"); + _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + rs.size()), os_commit_granularity); + _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false); + } + + virtual void commit_regions(uintptr_t start_idx, size_t num_regions) { + for (uintptr_t i = start_idx; i < start_idx + num_regions; i++) { + assert(!_commit_map.at(i), err_msg("Trying to commit storage at region "INTPTR_FORMAT" that is already committed", i)); + uintptr_t idx = region_idx_to_page_idx(i); + uint old_refcount = _refcounts.get_by_index(idx); + if (old_refcount == 0) { + _storage.commit(idx, 1); + } + _refcounts.set_by_index(idx, old_refcount + 1); + _commit_map.set_bit(i); + fire_on_commit(i, 1); + } + } + + virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions) { + for (uintptr_t i = start_idx; i < start_idx + num_regions; i++) { + assert(_commit_map.at(i), err_msg("Trying to uncommit storage at region "INTPTR_FORMAT" that is not committed", i)); + uintptr_t idx = region_idx_to_page_idx(i); + uint old_refcount = _refcounts.get_by_index(idx); + assert(old_refcount > 0, "must be"); + if (old_refcount == 1) { + _storage.uncommit(idx, 1); + } + _refcounts.set_by_index(idx, old_refcount - 1); + _commit_map.clear_bit(i); + } + } +}; + +void G1RegionToSpaceMapper::fire_on_commit(uint start_idx, size_t num_regions) { + if (_listener != NULL) { + _listener->on_commit(start_idx, num_regions); + } +} + +G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_mapper(ReservedSpace rs, + size_t os_commit_granularity, + size_t region_granularity, + size_t commit_factor, + MemoryType type) { + + if (region_granularity >= (os_commit_granularity * commit_factor)) { + return new G1RegionsLargerThanCommitSizeMapper(rs, os_commit_granularity, region_granularity, commit_factor, type); + } else { + return new G1RegionsSmallerThanCommitSizeMapper(rs, os_commit_granularity, region_granularity, commit_factor, type); + } +}