1 /* 2 * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc_implementation/g1/g1BiasedArray.hpp" 27 #include "gc_implementation/g1/g1RegionToSpaceMapper.hpp" 28 #include "memory/allocation.inline.hpp" 29 #include "runtime/virtualspace.hpp" 30 #include "services/memTracker.hpp" 31 #include "utilities/bitMap.inline.hpp" 32 33 G1RegionToSpaceMapper::G1RegionToSpaceMapper(ReservedSpace rs, 34 size_t actual_size, 35 size_t commit_granularity, 36 size_t region_granularity, 37 MemoryType type) : 38 _storage(), 39 _commit_granularity(commit_granularity), 40 _region_granularity(region_granularity), 41 _listener(NULL), 42 _commit_map() { 43 guarantee(is_power_of_2(commit_granularity), "must be"); 44 guarantee(is_power_of_2(region_granularity), "must be"); 45 _storage.initialize_with_granularity(rs, actual_size, commit_granularity); 46 47 MemTracker::record_virtual_memory_type((address)rs.base(), type); 48 } 49 50 // G1RegionToSpaceMapper implementation where the region granularity is larger than 51 // or the same as the commit granularity. 52 // Basically, the space corresponding to one region region spans several OS pages. 53 class G1RegionsLargerThanCommitSizeMapper : public G1RegionToSpaceMapper { 54 private: 55 size_t _pages_per_region; 56 57 public: 58 G1RegionsLargerThanCommitSizeMapper(ReservedSpace rs, 59 size_t actual_size, 60 size_t os_commit_granularity, 61 size_t alloc_granularity, 62 size_t commit_factor, 63 MemoryType type) : 64 G1RegionToSpaceMapper(rs, actual_size, os_commit_granularity, alloc_granularity, type), 65 _pages_per_region(alloc_granularity / (os_commit_granularity * commit_factor)) { 66 67 guarantee(alloc_granularity >= os_commit_granularity, "allocation granularity smaller than commit granularity"); 68 _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false); 69 } 70 71 virtual void commit_regions(uintptr_t start_idx, size_t num_regions) { 72 bool zero_filled = _storage.commit(start_idx * _pages_per_region, num_regions * _pages_per_region); 73 _commit_map.set_range(start_idx, start_idx + num_regions); 74 fire_on_commit(start_idx, num_regions, zero_filled); 75 } 76 77 virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions) { 78 _storage.uncommit(start_idx * _pages_per_region, num_regions * _pages_per_region); 79 _commit_map.clear_range(start_idx, start_idx + num_regions); 80 } 81 }; 82 83 // G1RegionToSpaceMapper implementation where the region granularity is smaller 84 // than the commit granularity. 85 // Basically, the contents of one OS page span several regions. 86 class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper { 87 private: 88 class CommitRefcountArray : public G1BiasedMappedArray<uint> { 89 protected: 90 virtual uint default_value() const { return 0; } 91 }; 92 93 size_t _regions_per_page; 94 95 CommitRefcountArray _refcounts; 96 97 uintptr_t region_idx_to_page_idx(uint region) const { 98 return region / _regions_per_page; 99 } 100 101 public: 102 G1RegionsSmallerThanCommitSizeMapper(ReservedSpace rs, 103 size_t actual_size, 104 size_t os_commit_granularity, 105 size_t alloc_granularity, 106 size_t commit_factor, 107 MemoryType type) : 108 G1RegionToSpaceMapper(rs, actual_size, os_commit_granularity, alloc_granularity, type), 109 _regions_per_page((os_commit_granularity * commit_factor) / alloc_granularity), _refcounts() { 110 111 guarantee((os_commit_granularity * commit_factor) >= alloc_granularity, "allocation granularity smaller than commit granularity"); 112 _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + align_size_up(rs.size(), os_commit_granularity)), os_commit_granularity); 113 _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false); 114 } 115 116 virtual void commit_regions(uintptr_t start_idx, size_t num_regions) { 117 for (uintptr_t i = start_idx; i < start_idx + num_regions; i++) { 118 assert(!_commit_map.at(i), err_msg("Trying to commit storage at region "INTPTR_FORMAT" that is already committed", i)); 119 uintptr_t idx = region_idx_to_page_idx(i); 120 uint old_refcount = _refcounts.get_by_index(idx); 121 bool zero_filled = false; 122 if (old_refcount == 0) { 123 zero_filled = _storage.commit(idx, 1); 124 } 125 _refcounts.set_by_index(idx, old_refcount + 1); 126 _commit_map.set_bit(i); 127 fire_on_commit(i, 1, zero_filled); 128 } 129 } 130 131 virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions) { 132 for (uintptr_t i = start_idx; i < start_idx + num_regions; i++) { 133 assert(_commit_map.at(i), err_msg("Trying to uncommit storage at region "INTPTR_FORMAT" that is not committed", i)); 134 uintptr_t idx = region_idx_to_page_idx(i); 135 uint old_refcount = _refcounts.get_by_index(idx); 136 assert(old_refcount > 0, "must be"); 137 if (old_refcount == 1) { 138 _storage.uncommit(idx, 1); 139 } 140 _refcounts.set_by_index(idx, old_refcount - 1); 141 _commit_map.clear_bit(i); 142 } 143 } 144 }; 145 146 void G1RegionToSpaceMapper::fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled) { 147 if (_listener != NULL) { 148 _listener->on_commit(start_idx, num_regions, zero_filled); 149 } 150 } 151 152 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_mapper(ReservedSpace rs, 153 size_t actual_size, 154 size_t os_commit_granularity, 155 size_t region_granularity, 156 size_t commit_factor, 157 MemoryType type) { 158 159 if (region_granularity >= (os_commit_granularity * commit_factor)) { 160 return new G1RegionsLargerThanCommitSizeMapper(rs, actual_size, os_commit_granularity, region_granularity, commit_factor, type); 161 } else { 162 return new G1RegionsSmallerThanCommitSizeMapper(rs, actual_size, os_commit_granularity, region_granularity, commit_factor, type); 163 } 164 }