Mercurial > hg > graal-compiler
annotate src/share/vm/memory/heap.cpp @ 10114:a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
Summary: Remove continous free block requirement
Reviewed-by: kvn
| author | neliasso |
|---|---|
| date | Thu, 11 Apr 2013 13:57:44 +0200 |
| parents | cc32ccaaf47f |
| children | 836a62f43af9 740e263c80c6 |
| rev | line source |
|---|---|
| 0 | 1 /* |
|
6842
b9a9ed0f8eeb
7197424: update copyright year to match last edit in jdk8 hotspot repository
mikael
parents:
6197
diff
changeset
|
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1123
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
|
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1123
diff
changeset
|
20 * or visit www.oracle.com if you need additional information or have any |
|
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1123
diff
changeset
|
21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #include "precompiled.hpp" |
| 26 #include "memory/heap.hpp" | |
| 27 #include "oops/oop.inline.hpp" | |
| 28 #include "runtime/os.hpp" | |
| 6197 | 29 #include "services/memTracker.hpp" |
| 0 | 30 |
| 31 size_t CodeHeap::header_size() { | |
| 32 return sizeof(HeapBlock); | |
| 33 } | |
| 34 | |
| 35 | |
| 36 // Implementation of Heap | |
| 37 | |
| 38 CodeHeap::CodeHeap() { | |
| 39 _number_of_committed_segments = 0; | |
| 40 _number_of_reserved_segments = 0; | |
| 41 _segment_size = 0; | |
| 42 _log2_segment_size = 0; | |
| 43 _next_segment = 0; | |
| 44 _freelist = NULL; | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
45 _freelist_segments = 0; |
| 0 | 46 } |
| 47 | |
| 48 | |
| 49 void CodeHeap::mark_segmap_as_free(size_t beg, size_t end) { | |
| 50 assert(0 <= beg && beg < _number_of_committed_segments, "interval begin out of bounds"); | |
| 51 assert(beg < end && end <= _number_of_committed_segments, "interval end out of bounds"); | |
| 52 // setup _segmap pointers for faster indexing | |
| 53 address p = (address)_segmap.low() + beg; | |
| 54 address q = (address)_segmap.low() + end; | |
| 55 // initialize interval | |
| 56 while (p < q) *p++ = 0xFF; | |
| 57 } | |
| 58 | |
| 59 | |
| 60 void CodeHeap::mark_segmap_as_used(size_t beg, size_t end) { | |
| 61 assert(0 <= beg && beg < _number_of_committed_segments, "interval begin out of bounds"); | |
| 62 assert(beg < end && end <= _number_of_committed_segments, "interval end out of bounds"); | |
| 63 // setup _segmap pointers for faster indexing | |
| 64 address p = (address)_segmap.low() + beg; | |
| 65 address q = (address)_segmap.low() + end; | |
| 66 // initialize interval | |
| 67 int i = 0; | |
| 68 while (p < q) { | |
| 69 *p++ = i++; | |
| 70 if (i == 0xFF) i = 1; | |
| 71 } | |
| 72 } | |
| 73 | |
| 74 | |
| 75 static size_t align_to_page_size(size_t size) { | |
| 76 const size_t alignment = (size_t)os::vm_page_size(); | |
| 77 assert(is_power_of_2(alignment), "no kidding ???"); | |
| 78 return (size + alignment - 1) & ~(alignment - 1); | |
| 79 } | |
| 80 | |
| 81 | |
| 82 void CodeHeap::on_code_mapping(char* base, size_t size) { | |
| 83 #ifdef LINUX | |
| 84 extern void linux_wrap_code(char* base, size_t size); | |
| 85 linux_wrap_code(base, size); | |
| 86 #endif | |
| 87 } | |
| 88 | |
| 89 | |
| 90 bool CodeHeap::reserve(size_t reserved_size, size_t committed_size, | |
| 91 size_t segment_size) { | |
| 92 assert(reserved_size >= committed_size, "reserved < committed"); | |
| 93 assert(segment_size >= sizeof(FreeBlock), "segment size is too small"); | |
| 94 assert(is_power_of_2(segment_size), "segment_size must be a power of 2"); | |
| 95 | |
| 96 _segment_size = segment_size; | |
| 97 _log2_segment_size = exact_log2(segment_size); | |
| 98 | |
| 99 // Reserve and initialize space for _memory. | |
|
79
82db0859acbe
6642862: Code cache allocation fails with large pages after 6588638
jcoomes
parents:
0
diff
changeset
|
100 const size_t page_size = os::can_execute_large_page_memory() ? |
|
82db0859acbe
6642862: Code cache allocation fails with large pages after 6588638
jcoomes
parents:
0
diff
changeset
|
101 os::page_size_for_region(committed_size, reserved_size, 8) : |
|
82db0859acbe
6642862: Code cache allocation fails with large pages after 6588638
jcoomes
parents:
0
diff
changeset
|
102 os::vm_page_size(); |
| 0 | 103 const size_t granularity = os::vm_allocation_granularity(); |
| 104 const size_t r_align = MAX2(page_size, granularity); | |
| 105 const size_t r_size = align_size_up(reserved_size, r_align); | |
| 106 const size_t c_size = align_size_up(committed_size, page_size); | |
| 107 | |
| 108 const size_t rs_align = page_size == (size_t) os::vm_page_size() ? 0 : | |
| 109 MAX2(page_size, granularity); | |
| 656 | 110 ReservedCodeSpace rs(r_size, rs_align, rs_align > 0); |
| 0 | 111 os::trace_page_sizes("code heap", committed_size, reserved_size, page_size, |
| 112 rs.base(), rs.size()); | |
| 113 if (!_memory.initialize(rs, c_size)) { | |
| 114 return false; | |
| 115 } | |
| 116 | |
| 117 on_code_mapping(_memory.low(), _memory.committed_size()); | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
118 _number_of_committed_segments = size_to_segments(_memory.committed_size()); |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
119 _number_of_reserved_segments = size_to_segments(_memory.reserved_size()); |
| 0 | 120 assert(_number_of_reserved_segments >= _number_of_committed_segments, "just checking"); |
| 121 | |
| 122 // reserve space for _segmap | |
| 123 if (!_segmap.initialize(align_to_page_size(_number_of_reserved_segments), align_to_page_size(_number_of_committed_segments))) { | |
| 124 return false; | |
| 125 } | |
| 6197 | 126 |
| 127 MemTracker::record_virtual_memory_type((address)_segmap.low_boundary(), mtCode); | |
| 128 | |
| 0 | 129 assert(_segmap.committed_size() >= (size_t) _number_of_committed_segments, "could not commit enough space for segment map"); |
| 130 assert(_segmap.reserved_size() >= (size_t) _number_of_reserved_segments , "could not reserve enough space for segment map"); | |
| 131 assert(_segmap.reserved_size() >= _segmap.committed_size() , "just checking"); | |
| 132 | |
| 133 // initialize remaining instance variables | |
| 134 clear(); | |
| 135 return true; | |
| 136 } | |
| 137 | |
| 138 | |
| 139 void CodeHeap::release() { | |
| 140 Unimplemented(); | |
| 141 } | |
| 142 | |
| 143 | |
| 144 bool CodeHeap::expand_by(size_t size) { | |
| 145 // expand _memory space | |
| 146 size_t dm = align_to_page_size(_memory.committed_size() + size) - _memory.committed_size(); | |
| 147 if (dm > 0) { | |
| 148 char* base = _memory.low() + _memory.committed_size(); | |
| 149 if (!_memory.expand_by(dm)) return false; | |
| 150 on_code_mapping(base, dm); | |
| 151 size_t i = _number_of_committed_segments; | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
152 _number_of_committed_segments = size_to_segments(_memory.committed_size()); |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
153 assert(_number_of_reserved_segments == size_to_segments(_memory.reserved_size()), "number of reserved segments should not change"); |
| 0 | 154 assert(_number_of_reserved_segments >= _number_of_committed_segments, "just checking"); |
| 155 // expand _segmap space | |
| 156 size_t ds = align_to_page_size(_number_of_committed_segments) - _segmap.committed_size(); | |
| 157 if (ds > 0) { | |
| 158 if (!_segmap.expand_by(ds)) return false; | |
| 159 } | |
| 160 assert(_segmap.committed_size() >= (size_t) _number_of_committed_segments, "just checking"); | |
| 161 // initialize additional segmap entries | |
| 162 mark_segmap_as_free(i, _number_of_committed_segments); | |
| 163 } | |
| 164 return true; | |
| 165 } | |
| 166 | |
| 167 | |
| 168 void CodeHeap::shrink_by(size_t size) { | |
| 169 Unimplemented(); | |
| 170 } | |
| 171 | |
| 172 | |
| 173 void CodeHeap::clear() { | |
| 174 _next_segment = 0; | |
| 175 mark_segmap_as_free(0, _number_of_committed_segments); | |
| 176 } | |
| 177 | |
| 178 | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
179 void* CodeHeap::allocate(size_t instance_size, bool is_critical) { |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
180 size_t number_of_segments = size_to_segments(instance_size + sizeof(HeapBlock)); |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
181 assert(segments_to_size(number_of_segments) >= sizeof(FreeBlock), "not enough room for FreeList"); |
| 0 | 182 |
| 183 // First check if we can satify request from freelist | |
| 184 debug_only(verify()); | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
185 HeapBlock* block = search_freelist(number_of_segments, is_critical); |
| 0 | 186 debug_only(if (VerifyCodeCacheOften) verify()); |
| 187 if (block != NULL) { | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
188 assert(block->length() >= number_of_segments && block->length() < number_of_segments + CodeCacheMinBlockLength, "sanity check"); |
| 0 | 189 assert(!block->free(), "must be marked free"); |
| 190 #ifdef ASSERT | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
191 memset((void *)block->allocated_space(), badCodeHeapNewVal, instance_size); |
| 0 | 192 #endif |
| 193 return block->allocated_space(); | |
| 194 } | |
| 195 | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
196 // Ensure minimum size for allocation to the heap. |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
197 if (number_of_segments < CodeCacheMinBlockLength) { |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
198 number_of_segments = CodeCacheMinBlockLength; |
| 0 | 199 } |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
200 |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
201 if (!is_critical) { |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
202 // Make sure the allocation fits in the unallocated heap without using |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
203 // the CodeCacheMimimumFreeSpace that is reserved for critical allocations. |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
204 if (segments_to_size(number_of_segments) > (heap_unallocated_capacity() - CodeCacheMinimumFreeSpace)) { |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
205 // Fail allocation |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
206 return NULL; |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
207 } |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
208 } |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
209 |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
210 if (_next_segment + number_of_segments <= _number_of_committed_segments) { |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
211 mark_segmap_as_used(_next_segment, _next_segment + number_of_segments); |
| 0 | 212 HeapBlock* b = block_at(_next_segment); |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
213 b->initialize(number_of_segments); |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
214 _next_segment += number_of_segments; |
| 0 | 215 #ifdef ASSERT |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
216 memset((void *)b->allocated_space(), badCodeHeapNewVal, instance_size); |
| 0 | 217 #endif |
| 218 return b->allocated_space(); | |
| 219 } else { | |
| 220 return NULL; | |
| 221 } | |
| 222 } | |
| 223 | |
| 224 | |
| 225 void CodeHeap::deallocate(void* p) { | |
| 226 assert(p == find_start(p), "illegal deallocation"); | |
| 227 // Find start of HeapBlock | |
| 228 HeapBlock* b = (((HeapBlock *)p) - 1); | |
| 229 assert(b->allocated_space() == p, "sanity check"); | |
| 230 #ifdef ASSERT | |
| 231 memset((void *)b->allocated_space(), | |
| 232 badCodeHeapFreeVal, | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
233 segments_to_size(b->length()) - sizeof(HeapBlock)); |
| 0 | 234 #endif |
| 235 add_to_freelist(b); | |
| 236 | |
| 237 debug_only(if (VerifyCodeCacheOften) verify()); | |
| 238 } | |
| 239 | |
| 240 | |
| 241 void* CodeHeap::find_start(void* p) const { | |
| 242 if (!contains(p)) { | |
| 243 return NULL; | |
| 244 } | |
| 245 size_t i = segment_for(p); | |
| 246 address b = (address)_segmap.low(); | |
| 247 if (b[i] == 0xFF) { | |
| 248 return NULL; | |
| 249 } | |
| 250 while (b[i] > 0) i -= (int)b[i]; | |
| 251 HeapBlock* h = block_at(i); | |
| 252 if (h->free()) { | |
| 253 return NULL; | |
| 254 } | |
| 255 return h->allocated_space(); | |
| 256 } | |
| 257 | |
| 258 | |
| 259 size_t CodeHeap::alignment_unit() const { | |
| 260 // this will be a power of two | |
| 261 return _segment_size; | |
| 262 } | |
| 263 | |
| 264 | |
| 265 size_t CodeHeap::alignment_offset() const { | |
| 266 // The lowest address in any allocated block will be | |
| 267 // equal to alignment_offset (mod alignment_unit). | |
| 268 return sizeof(HeapBlock) & (_segment_size - 1); | |
| 269 } | |
| 270 | |
| 271 // Finds the next free heapblock. If the current one is free, that it returned | |
| 272 void* CodeHeap::next_free(HeapBlock *b) const { | |
| 273 // Since free blocks are merged, there is max. on free block | |
| 274 // between two used ones | |
| 275 if (b != NULL && b->free()) b = next_block(b); | |
| 276 assert(b == NULL || !b->free(), "must be in use or at end of heap"); | |
| 277 return (b == NULL) ? NULL : b->allocated_space(); | |
| 278 } | |
| 279 | |
| 280 // Returns the first used HeapBlock | |
| 281 HeapBlock* CodeHeap::first_block() const { | |
| 282 if (_next_segment > 0) | |
| 283 return block_at(0); | |
| 284 return NULL; | |
| 285 } | |
| 286 | |
| 287 HeapBlock *CodeHeap::block_start(void *q) const { | |
| 288 HeapBlock* b = (HeapBlock*)find_start(q); | |
| 289 if (b == NULL) return NULL; | |
| 290 return b - 1; | |
| 291 } | |
| 292 | |
| 293 // Returns the next Heap block an offset into one | |
| 294 HeapBlock* CodeHeap::next_block(HeapBlock *b) const { | |
| 295 if (b == NULL) return NULL; | |
| 296 size_t i = segment_for(b) + b->length(); | |
| 297 if (i < _next_segment) | |
| 298 return block_at(i); | |
| 299 return NULL; | |
| 300 } | |
| 301 | |
| 302 | |
| 303 // Returns current capacity | |
| 304 size_t CodeHeap::capacity() const { | |
| 305 return _memory.committed_size(); | |
| 306 } | |
| 307 | |
| 308 size_t CodeHeap::max_capacity() const { | |
| 309 return _memory.reserved_size(); | |
| 310 } | |
| 311 | |
| 312 size_t CodeHeap::allocated_capacity() const { | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
313 // size of used heap - size on freelist |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
314 return segments_to_size(_next_segment - _freelist_segments); |
| 0 | 315 } |
| 316 | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
317 // Returns size of the unallocated heap block |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
318 size_t CodeHeap::heap_unallocated_capacity() const { |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
319 // Total number of segments - number currently used |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
320 return segments_to_size(_number_of_reserved_segments - _next_segment); |
|
2091
51bd2d261853
7008325: CodeCache exhausted on sparc starting from hs20b04
kvn
parents:
1972
diff
changeset
|
321 } |
|
51bd2d261853
7008325: CodeCache exhausted on sparc starting from hs20b04
kvn
parents:
1972
diff
changeset
|
322 |
| 0 | 323 // Free list management |
| 324 | |
| 325 FreeBlock *CodeHeap::following_block(FreeBlock *b) { | |
| 326 return (FreeBlock*)(((address)b) + _segment_size * b->length()); | |
| 327 } | |
| 328 | |
| 329 // Inserts block b after a | |
| 330 void CodeHeap::insert_after(FreeBlock* a, FreeBlock* b) { | |
| 331 assert(a != NULL && b != NULL, "must be real pointers"); | |
| 332 | |
| 333 // Link b into the list after a | |
| 334 b->set_link(a->link()); | |
| 335 a->set_link(b); | |
| 336 | |
| 337 // See if we can merge blocks | |
| 338 merge_right(b); // Try to make b bigger | |
| 339 merge_right(a); // Try to make a include b | |
| 340 } | |
| 341 | |
| 342 // Try to merge this block with the following block | |
| 343 void CodeHeap::merge_right(FreeBlock *a) { | |
| 344 assert(a->free(), "must be a free block"); | |
| 345 if (following_block(a) == a->link()) { | |
| 346 assert(a->link() != NULL && a->link()->free(), "must be free too"); | |
| 347 // Update block a to include the following block | |
| 348 a->set_length(a->length() + a->link()->length()); | |
| 349 a->set_link(a->link()->link()); | |
| 350 // Update find_start map | |
| 351 size_t beg = segment_for(a); | |
| 352 mark_segmap_as_used(beg, beg + a->length()); | |
| 353 } | |
| 354 } | |
| 355 | |
| 356 void CodeHeap::add_to_freelist(HeapBlock *a) { | |
| 357 FreeBlock* b = (FreeBlock*)a; | |
| 358 assert(b != _freelist, "cannot be removed twice"); | |
| 359 | |
| 360 // Mark as free and update free space count | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
361 _freelist_segments += b->length(); |
| 0 | 362 b->set_free(); |
| 363 | |
| 364 // First element in list? | |
| 365 if (_freelist == NULL) { | |
| 366 _freelist = b; | |
| 367 b->set_link(NULL); | |
| 368 return; | |
| 369 } | |
| 370 | |
| 371 // Scan for right place to put into list. List | |
| 372 // is sorted by increasing addresseses | |
| 373 FreeBlock* prev = NULL; | |
| 374 FreeBlock* cur = _freelist; | |
| 375 while(cur != NULL && cur < b) { | |
| 376 assert(prev == NULL || prev < cur, "must be ordered"); | |
| 377 prev = cur; | |
| 378 cur = cur->link(); | |
| 379 } | |
| 380 | |
| 381 assert( (prev == NULL && b < _freelist) || | |
| 382 (prev < b && (cur == NULL || b < cur)), "list must be ordered"); | |
| 383 | |
| 384 if (prev == NULL) { | |
| 385 // Insert first in list | |
| 386 b->set_link(_freelist); | |
| 387 _freelist = b; | |
| 388 merge_right(_freelist); | |
| 389 } else { | |
| 390 insert_after(prev, b); | |
| 391 } | |
| 392 } | |
| 393 | |
| 394 // Search freelist for an entry on the list with the best fit | |
| 395 // Return NULL if no one was found | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
396 FreeBlock* CodeHeap::search_freelist(size_t length, bool is_critical) { |
| 0 | 397 FreeBlock *best_block = NULL; |
| 398 FreeBlock *best_prev = NULL; | |
| 399 size_t best_length = 0; | |
| 400 | |
| 401 // Search for smallest block which is bigger than length | |
| 402 FreeBlock *prev = NULL; | |
| 403 FreeBlock *cur = _freelist; | |
| 404 while(cur != NULL) { | |
| 405 size_t l = cur->length(); | |
| 406 if (l >= length && (best_block == NULL || best_length > l)) { | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
407 |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
408 // Non critical allocations are not allowed to use the last part of the code heap. |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
409 if (!is_critical) { |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
410 // Make sure the end of the allocation doesn't cross into the last part of the code heap |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
411 if (((size_t)cur + length) > ((size_t)high_boundary() - CodeCacheMinimumFreeSpace)) { |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
412 // the freelist is sorted by address - if one fails, all consecutive will also fail. |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
413 break; |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
414 } |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
415 } |
|
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
416 |
| 0 | 417 // Remember best block, its previous element, and its length |
| 418 best_block = cur; | |
| 419 best_prev = prev; | |
| 420 best_length = best_block->length(); | |
| 421 } | |
| 422 | |
| 423 // Next element in list | |
| 424 prev = cur; | |
| 425 cur = cur->link(); | |
| 426 } | |
| 427 | |
| 428 if (best_block == NULL) { | |
| 429 // None found | |
| 430 return NULL; | |
| 431 } | |
| 432 | |
| 433 assert((best_prev == NULL && _freelist == best_block ) || | |
| 434 (best_prev != NULL && best_prev->link() == best_block), "sanity check"); | |
| 435 | |
| 436 // Exact (or at least good enough) fit. Remove from list. | |
| 437 // Don't leave anything on the freelist smaller than CodeCacheMinBlockLength. | |
| 438 if (best_length < length + CodeCacheMinBlockLength) { | |
| 439 length = best_length; | |
| 440 if (best_prev == NULL) { | |
| 441 assert(_freelist == best_block, "sanity check"); | |
| 442 _freelist = _freelist->link(); | |
| 443 } else { | |
| 444 // Unmap element | |
| 445 best_prev->set_link(best_block->link()); | |
| 446 } | |
| 447 } else { | |
| 448 // Truncate block and return a pointer to the following block | |
| 449 best_block->set_length(best_length - length); | |
| 450 best_block = following_block(best_block); | |
| 451 // Set used bit and length on new block | |
| 452 size_t beg = segment_for(best_block); | |
| 453 mark_segmap_as_used(beg, beg + length); | |
| 454 best_block->set_length(length); | |
| 455 } | |
| 456 | |
| 457 best_block->set_used(); | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
458 _freelist_segments -= length; |
| 0 | 459 return best_block; |
| 460 } | |
| 461 | |
| 462 //---------------------------------------------------------------------------- | |
| 463 // Non-product code | |
| 464 | |
| 465 #ifndef PRODUCT | |
| 466 | |
| 467 void CodeHeap::print() { | |
| 468 tty->print_cr("The Heap"); | |
| 469 } | |
| 470 | |
| 471 #endif | |
| 472 | |
| 473 void CodeHeap::verify() { | |
| 474 // Count the number of blocks on the freelist, and the amount of space | |
| 475 // represented. | |
| 476 int count = 0; | |
| 477 size_t len = 0; | |
| 478 for(FreeBlock* b = _freelist; b != NULL; b = b->link()) { | |
| 479 len += b->length(); | |
| 480 count++; | |
| 481 } | |
| 482 | |
| 483 // Verify that freelist contains the right amount of free space | |
|
10114
a7fb14888912
8006952: Slow VM due to excessive code cache freelist iteration
neliasso
parents:
9060
diff
changeset
|
484 // guarantee(len == _freelist_segments, "wrong freelist"); |
| 0 | 485 |
| 486 // Verify that the number of free blocks is not out of hand. | |
| 487 static int free_block_threshold = 10000; | |
| 488 if (count > free_block_threshold) { | |
| 489 warning("CodeHeap: # of free blocks > %d", free_block_threshold); | |
| 490 // Double the warning limit | |
| 491 free_block_threshold *= 2; | |
| 492 } | |
| 493 | |
| 494 // Verify that the freelist contains the same number of free blocks that is | |
| 495 // found on the full list. | |
| 496 for(HeapBlock *h = first_block(); h != NULL; h = next_block(h)) { | |
| 497 if (h->free()) count--; | |
| 498 } | |
|
1123
167c2986d91b
6843629: Make current hotspot build part of jdk5 control build
phh
parents:
844
diff
changeset
|
499 // guarantee(count == 0, "missing free blocks"); |
| 0 | 500 } |