1 /* 2 * Copyright (c) 2001, 2017, 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 "logging/log.hpp" 26 #include "precompiled.hpp" 27 #include "gc/g1/g1BiasedArray.hpp" 28 #include "gc/g1/g1RegionToSpaceMapper.hpp" 29 #include "memory/allocation.inline.hpp" 30 #include "memory/virtualspace.hpp" 31 #include "runtime/java.hpp" 32 #include "services/memTracker.hpp" 33 #include "utilities/align.hpp" 34 #include "utilities/bitMap.inline.hpp" 35 #include "utilities/formatBuffer.hpp" 36 37 G1RegionToSpaceMapper::G1RegionToSpaceMapper(ReservedSpace rs, 38 size_t used_size, 39 size_t page_size, 40 size_t region_granularity, 41 size_t commit_factor, 42 MemoryType type) : 43 _listener(NULL), 44 _storage(rs, used_size, page_size), 45 _region_granularity(region_granularity), 46 _commit_map(rs.size() * commit_factor / region_granularity, mtGC) { 47 guarantee(is_power_of_2(page_size), "must be"); 48 guarantee(is_power_of_2(region_granularity), "must be"); 49 50 MemTracker::record_virtual_memory_type((address)rs.base(), type); 51 } 52 53 // G1RegionToSpaceMapper implementation where the region granularity is larger than 54 // or the same as the commit granularity. 55 // Basically, the space corresponding to one region region spans several OS pages. 56 class G1RegionsLargerThanCommitSizeMapper : public G1RegionToSpaceMapper { 57 private: 58 size_t _pages_per_region; 59 60 public: 61 G1RegionsLargerThanCommitSizeMapper(ReservedSpace rs, 62 size_t actual_size, 63 size_t page_size, 64 size_t alloc_granularity, 65 size_t commit_factor, 66 MemoryType type) : 67 G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type), 68 _pages_per_region(alloc_granularity / (page_size * commit_factor)) { 69 70 guarantee(alloc_granularity >= page_size, "allocation granularity smaller than commit granularity"); 71 } 72 73 virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) { 74 size_t const start_page = (size_t)start_idx * _pages_per_region; 75 bool zero_filled = _storage.commit(start_page, num_regions * _pages_per_region); 76 if (AlwaysPreTouch) { 77 _storage.pretouch(start_page, num_regions * _pages_per_region, pretouch_gang); 78 } 79 _commit_map.set_range(start_idx, start_idx + num_regions); 80 fire_on_commit(start_idx, num_regions, zero_filled); 81 } 82 83 virtual void uncommit_regions(uint start_idx, size_t num_regions) { 84 _storage.uncommit((size_t)start_idx * _pages_per_region, num_regions * _pages_per_region); 85 _commit_map.clear_range(start_idx, start_idx + num_regions); 86 } 87 }; 88 89 // G1RegionToSpaceMapper implementation where the region granularity is smaller 90 // than the commit granularity. 91 // Basically, the contents of one OS page span several regions. 92 class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper { 93 private: 94 class CommitRefcountArray : public G1BiasedMappedArray<uint> { 95 protected: 96 virtual uint default_value() const { return 0; } 97 }; 98 99 size_t _regions_per_page; 100 101 CommitRefcountArray _refcounts; 102 103 uintptr_t region_idx_to_page_idx(uint region) const { 104 return region / _regions_per_page; 105 } 106 107 public: 108 G1RegionsSmallerThanCommitSizeMapper(ReservedSpace rs, 109 size_t actual_size, 110 size_t page_size, 111 size_t alloc_granularity, 112 size_t commit_factor, 113 MemoryType type) : 114 G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type), 115 _regions_per_page((page_size * commit_factor) / alloc_granularity), _refcounts() { 116 117 guarantee((page_size * commit_factor) >= alloc_granularity, "allocation granularity smaller than commit granularity"); 118 _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + align_up(rs.size(), page_size)), page_size); 119 } 120 121 virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) { 122 size_t const NoPage = ~(size_t)0; 123 124 size_t first_committed = NoPage; 125 size_t num_committed = 0; 126 127 bool all_zero_filled = true; 128 129 for (uint i = start_idx; i < start_idx + num_regions; i++) { 130 assert(!_commit_map.at(i), "Trying to commit storage at region %u that is already committed", i); 131 size_t idx = region_idx_to_page_idx(i); 132 uint old_refcount = _refcounts.get_by_index(idx); 133 134 bool zero_filled = false; 135 if (old_refcount == 0) { 136 if (first_committed == NoPage) { 137 first_committed = idx; 138 num_committed = 1; 139 } else { 140 num_committed++; 141 } 142 zero_filled = _storage.commit(idx, 1); 143 } 144 all_zero_filled &= zero_filled; 145 146 _refcounts.set_by_index(idx, old_refcount + 1); 147 _commit_map.set_bit(i); 148 } 149 if (AlwaysPreTouch && num_committed > 0) { 150 _storage.pretouch(first_committed, num_committed, pretouch_gang); 151 } 152 fire_on_commit(start_idx, num_regions, all_zero_filled); 153 } 154 155 virtual void uncommit_regions(uint start_idx, size_t num_regions) { 156 for (uint i = start_idx; i < start_idx + num_regions; i++) { 157 assert(_commit_map.at(i), "Trying to uncommit storage at region %u that is not committed", i); 158 size_t idx = region_idx_to_page_idx(i); 159 uint old_refcount = _refcounts.get_by_index(idx); 160 assert(old_refcount > 0, "must be"); 161 if (old_refcount == 1) { 162 _storage.uncommit(idx, 1); 163 } 164 _refcounts.set_by_index(idx, old_refcount - 1); 165 _commit_map.clear_bit(i); 166 } 167 } 168 }; 169 170 void G1RegionToSpaceMapper::fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled) { 171 if (_listener != NULL) { 172 _listener->on_commit(start_idx, num_regions, zero_filled); 173 } 174 } 175 176 static bool map_nvdimm_space(ReservedSpace rs) { 177 assert(AllocateOldGenAt != NULL, ""); 178 int _backing_fd = os::create_file_for_heap(AllocateOldGenAt); 179 if (_backing_fd == -1) { 180 return false; 181 log_error(gc, init)("Could not create file for Old generation at location %s", AllocateOldGenAt); 182 } 183 // commit this memory in nv-dimm 184 char* ret = os::attempt_reserve_memory_at(rs.size(), rs.base(), _backing_fd); 185 186 if (ret != rs.base()) { 187 if (ret != NULL) { 188 os::unmap_memory(rs.base(), rs.size()); 189 } 190 log_error(gc, init)("Error in mapping Old Gen to given AllocateOldGenAt = %s", AllocateOldGenAt); 191 return false; 192 } 193 return true; 194 } 195 196 G1RegionToHeteroSpaceMapper::G1RegionToHeteroSpaceMapper(ReservedSpace rs, 197 size_t actual_size, 198 size_t page_size, 199 size_t alloc_granularity, 200 size_t commit_factor, 201 MemoryType type) : 202 G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type), 203 _num_committed_dram(0), _num_committed_nvdimm(0), _success(false) { 204 assert(actual_size == 2 * MaxHeapSize, "For 2-way heterogenuous heap, reserved space is two times MaxHeapSize"); 205 206 // Since we need to re-map the reserved space - 'Xmx' to nv-dimm and 'Xmx' to dram, we need to release the reserved memory first. 207 // Because on some OSes (e.g. Windows) you cannot do a file mapping on memory reserved with regular mapping. 208 os::release_memory(rs.base(), rs.size()); 209 // First half of size Xmx is for nv-dimm. 210 ReservedSpace rs_nvdimm = rs.first_part(MaxHeapSize); 211 assert(rs_nvdimm.base() == rs.base(), "We should get the same base address"); 212 213 // Second half of reserved memory is mapped to dram. 214 ReservedSpace rs_dram = rs.last_part(MaxHeapSize); 215 216 assert(rs_dram.size() == rs_nvdimm.size() && rs_nvdimm.size() == MaxHeapSize, "They all should be same"); 217 218 // Reserve dram memory 219 char* base = os::attempt_reserve_memory_at(rs_dram.size(), rs_dram.base()); 220 if (base != rs_dram.base()) { 221 if (base != NULL) { 222 os::release_memory(base, rs_dram.size()); 223 } 224 log_error(gc, init)("Error in re-mapping memory on dram during G1 heterogenous memory initialization"); 225 return; 226 } 227 228 // We reserve and commit this entire space to NV-DIMM. 229 if (!map_nvdimm_space(rs_nvdimm)) { 230 log_error(gc, init)("Error in re-mapping memory to nv-dimm during G1 heterogenous memory initialization"); 231 return; 232 } 233 234 if (alloc_granularity >= (page_size * commit_factor)) { 235 _dram_mapper = new G1RegionsLargerThanCommitSizeMapper(rs_dram, rs_dram.size(), page_size, alloc_granularity, commit_factor, type); 236 } 237 else { 238 _dram_mapper = new G1RegionsSmallerThanCommitSizeMapper(rs_dram, rs_dram.size(), page_size, alloc_granularity, commit_factor, type); 239 } 240 241 _start_index_of_nvdimm = 0; 242 _start_index_of_dram = (uint)(rs_nvdimm.size() / alloc_granularity); 243 _success = true; 244 } 245 246 void G1RegionToHeteroSpaceMapper::commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) { 247 uint end_idx = (start_idx + (uint)num_regions - 1); 248 249 uint num_dram = end_idx >= _start_index_of_dram ? MIN2((end_idx - _start_index_of_dram + 1), (uint)num_regions) : 0; 250 uint num_nvdimm = (uint)num_regions - num_dram; 251 252 if (num_nvdimm > 0) { 253 // We do not need to commit nv-dimm regions, since they are committed in the beginning. 254 _num_committed_nvdimm += num_nvdimm; 255 } 256 if (num_dram > 0) { 257 _dram_mapper->commit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, num_dram, pretouch_gang); 258 _num_committed_dram += num_dram; 259 } 260 } 261 262 void G1RegionToHeteroSpaceMapper::uncommit_regions(uint start_idx, size_t num_regions) { 263 uint end_idx = (start_idx + (uint)num_regions - 1); 264 uint num_dram = end_idx >= _start_index_of_dram ? MIN2((end_idx - _start_index_of_dram + 1), (uint)num_regions) : 0; 265 uint num_nvdimm = (uint)num_regions - num_dram; 266 267 if (num_nvdimm > 0) { 268 // We do not uncommit memory for nv-dimm regions. 269 _num_committed_nvdimm -= num_nvdimm; 270 } 271 272 if (num_dram > 0) { 273 _dram_mapper->uncommit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, num_dram); 274 _num_committed_dram -= num_dram; 275 } 276 } 277 278 uint G1RegionToHeteroSpaceMapper::num_committed_dram() const { 279 return _num_committed_dram; 280 } 281 282 uint G1RegionToHeteroSpaceMapper::num_committed_nvdimm() const { 283 return _num_committed_nvdimm; 284 } 285 286 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_heap_mapper(ReservedSpace rs, 287 size_t actual_size, 288 size_t page_size, 289 size_t region_granularity, 290 size_t commit_factor, 291 MemoryType type) { 292 if (AllocateOldGenAt != NULL) { 293 G1RegionToHeteroSpaceMapper* mapper = new G1RegionToHeteroSpaceMapper(rs, actual_size, page_size, region_granularity, commit_factor, type); 294 if (!mapper->success()) { 295 delete mapper; 296 return NULL; 297 } 298 return (G1RegionToSpaceMapper*)mapper; 299 } else { 300 return create_mapper(rs, actual_size, page_size, region_granularity, commit_factor, type); 301 } 302 } 303 304 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_mapper(ReservedSpace rs, 305 size_t actual_size, 306 size_t page_size, 307 size_t region_granularity, 308 size_t commit_factor, 309 MemoryType type) { 310 if (region_granularity >= (page_size * commit_factor)) { 311 return new G1RegionsLargerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type); 312 } else { 313 return new G1RegionsSmallerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type); 314 } 315 }