tcache.c revision 58799f6d1c1f58053f4aac1b100ce9049c868039
1#define JEMALLOC_TCACHE_C_ 2#include "jemalloc/internal/jemalloc_internal.h" 3 4/******************************************************************************/ 5/* Data. */ 6 7malloc_tsd_data(, tcache, tcache_t *, NULL) 8malloc_tsd_data(, tcache_enabled, tcache_enabled_t, tcache_enabled_default) 9 10bool opt_tcache = true; 11ssize_t opt_lg_tcache_max = LG_TCACHE_MAXCLASS_DEFAULT; 12 13tcache_bin_info_t *tcache_bin_info; 14static unsigned stack_nelms; /* Total stack elms per tcache. */ 15 16size_t nhbins; 17size_t tcache_maxclass; 18 19/******************************************************************************/ 20 21size_t tcache_salloc(const void *ptr) 22{ 23 24 return (arena_salloc(ptr, false)); 25} 26 27void 28tcache_event_hard(tcache_t *tcache) 29{ 30 size_t binind = tcache->next_gc_bin; 31 tcache_bin_t *tbin = &tcache->tbins[binind]; 32 tcache_bin_info_t *tbin_info = &tcache_bin_info[binind]; 33 34 if (tbin->low_water > 0) { 35 /* 36 * Flush (ceiling) 3/4 of the objects below the low water mark. 37 */ 38 if (binind < NBINS) { 39 tcache_bin_flush_small(tbin, binind, tbin->ncached - 40 tbin->low_water + (tbin->low_water >> 2), tcache); 41 } else { 42 tcache_bin_flush_large(tbin, binind, tbin->ncached - 43 tbin->low_water + (tbin->low_water >> 2), tcache); 44 } 45 /* 46 * Reduce fill count by 2X. Limit lg_fill_div such that the 47 * fill count is always at least 1. 48 */ 49 if ((tbin_info->ncached_max >> (tbin->lg_fill_div+1)) >= 1) 50 tbin->lg_fill_div++; 51 } else if (tbin->low_water < 0) { 52 /* 53 * Increase fill count by 2X. Make sure lg_fill_div stays 54 * greater than 0. 55 */ 56 if (tbin->lg_fill_div > 1) 57 tbin->lg_fill_div--; 58 } 59 tbin->low_water = tbin->ncached; 60 61 tcache->next_gc_bin++; 62 if (tcache->next_gc_bin == nhbins) 63 tcache->next_gc_bin = 0; 64 tcache->ev_cnt = 0; 65} 66 67void * 68tcache_alloc_small_hard(tcache_t *tcache, tcache_bin_t *tbin, size_t binind) 69{ 70 void *ret; 71 72 arena_tcache_fill_small(tcache->arena, tbin, binind, 73 config_prof ? tcache->prof_accumbytes : 0); 74 if (config_prof) 75 tcache->prof_accumbytes = 0; 76 ret = tcache_alloc_easy(tbin); 77 78 return (ret); 79} 80 81void 82tcache_bin_flush_small(tcache_bin_t *tbin, size_t binind, unsigned rem, 83 tcache_t *tcache) 84{ 85 void *ptr; 86 unsigned i, nflush, ndeferred; 87 bool merged_stats = false; 88 89 assert(binind < NBINS); 90 assert(rem <= tbin->ncached); 91 92 for (nflush = tbin->ncached - rem; nflush > 0; nflush = ndeferred) { 93 /* Lock the arena bin associated with the first object. */ 94 arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE( 95 tbin->avail[0]); 96 arena_t *arena = chunk->arena; 97 arena_bin_t *bin = &arena->bins[binind]; 98 99 if (config_prof && arena == tcache->arena) { 100 if (arena_prof_accum(arena, tcache->prof_accumbytes)) 101 prof_idump(); 102 tcache->prof_accumbytes = 0; 103 } 104 105 malloc_mutex_lock(&bin->lock); 106 if (config_stats && arena == tcache->arena) { 107 assert(merged_stats == false); 108 merged_stats = true; 109 bin->stats.nflushes++; 110 bin->stats.nrequests += tbin->tstats.nrequests; 111 tbin->tstats.nrequests = 0; 112 } 113 ndeferred = 0; 114 for (i = 0; i < nflush; i++) { 115 ptr = tbin->avail[i]; 116 assert(ptr != NULL); 117 chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr); 118 if (chunk->arena == arena) { 119 size_t pageind = ((uintptr_t)ptr - 120 (uintptr_t)chunk) >> LG_PAGE; 121 arena_chunk_map_t *mapelm = 122 arena_mapp_get(chunk, pageind); 123 arena_dalloc_bin_locked(arena, chunk, ptr, 124 mapelm); 125 } else { 126 /* 127 * This object was allocated via a different 128 * arena bin than the one that is currently 129 * locked. Stash the object, so that it can be 130 * handled in a future pass. 131 */ 132 tbin->avail[ndeferred] = ptr; 133 ndeferred++; 134 } 135 } 136 malloc_mutex_unlock(&bin->lock); 137 } 138 if (config_stats && merged_stats == false) { 139 /* 140 * The flush loop didn't happen to flush to this thread's 141 * arena, so the stats didn't get merged. Manually do so now. 142 */ 143 arena_bin_t *bin = &tcache->arena->bins[binind]; 144 malloc_mutex_lock(&bin->lock); 145 bin->stats.nflushes++; 146 bin->stats.nrequests += tbin->tstats.nrequests; 147 tbin->tstats.nrequests = 0; 148 malloc_mutex_unlock(&bin->lock); 149 } 150 151 memmove(tbin->avail, &tbin->avail[tbin->ncached - rem], 152 rem * sizeof(void *)); 153 tbin->ncached = rem; 154 if ((int)tbin->ncached < tbin->low_water) 155 tbin->low_water = tbin->ncached; 156} 157 158void 159tcache_bin_flush_large(tcache_bin_t *tbin, size_t binind, unsigned rem, 160 tcache_t *tcache) 161{ 162 void *ptr; 163 unsigned i, nflush, ndeferred; 164 bool merged_stats = false; 165 166 assert(binind < nhbins); 167 assert(rem <= tbin->ncached); 168 169 for (nflush = tbin->ncached - rem; nflush > 0; nflush = ndeferred) { 170 /* Lock the arena associated with the first object. */ 171 arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE( 172 tbin->avail[0]); 173 arena_t *arena = chunk->arena; 174 UNUSED bool idump; 175 176 if (config_prof) 177 idump = false; 178 malloc_mutex_lock(&arena->lock); 179 if ((config_prof || config_stats) && arena == tcache->arena) { 180 if (config_prof) { 181 idump = arena_prof_accum_locked(arena, 182 tcache->prof_accumbytes); 183 tcache->prof_accumbytes = 0; 184 } 185 if (config_stats) { 186 merged_stats = true; 187 arena->stats.nrequests_large += 188 tbin->tstats.nrequests; 189 arena->stats.lstats[binind - NBINS].nrequests += 190 tbin->tstats.nrequests; 191 tbin->tstats.nrequests = 0; 192 } 193 } 194 ndeferred = 0; 195 for (i = 0; i < nflush; i++) { 196 ptr = tbin->avail[i]; 197 assert(ptr != NULL); 198 chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr); 199 if (chunk->arena == arena) 200 arena_dalloc_large_locked(arena, chunk, ptr); 201 else { 202 /* 203 * This object was allocated via a different 204 * arena than the one that is currently locked. 205 * Stash the object, so that it can be handled 206 * in a future pass. 207 */ 208 tbin->avail[ndeferred] = ptr; 209 ndeferred++; 210 } 211 } 212 malloc_mutex_unlock(&arena->lock); 213 if (config_prof && idump) 214 prof_idump(); 215 } 216 if (config_stats && merged_stats == false) { 217 /* 218 * The flush loop didn't happen to flush to this thread's 219 * arena, so the stats didn't get merged. Manually do so now. 220 */ 221 arena_t *arena = tcache->arena; 222 malloc_mutex_lock(&arena->lock); 223 arena->stats.nrequests_large += tbin->tstats.nrequests; 224 arena->stats.lstats[binind - NBINS].nrequests += 225 tbin->tstats.nrequests; 226 tbin->tstats.nrequests = 0; 227 malloc_mutex_unlock(&arena->lock); 228 } 229 230 memmove(tbin->avail, &tbin->avail[tbin->ncached - rem], 231 rem * sizeof(void *)); 232 tbin->ncached = rem; 233 if ((int)tbin->ncached < tbin->low_water) 234 tbin->low_water = tbin->ncached; 235} 236 237void 238tcache_arena_associate(tcache_t *tcache, arena_t *arena) 239{ 240 241 if (config_stats) { 242 /* Link into list of extant tcaches. */ 243 malloc_mutex_lock(&arena->lock); 244 ql_elm_new(tcache, link); 245 ql_tail_insert(&arena->tcache_ql, tcache, link); 246 malloc_mutex_unlock(&arena->lock); 247 } 248 tcache->arena = arena; 249} 250 251void 252tcache_arena_dissociate(tcache_t *tcache) 253{ 254 255 if (config_stats) { 256 /* Unlink from list of extant tcaches. */ 257 malloc_mutex_lock(&tcache->arena->lock); 258 ql_remove(&tcache->arena->tcache_ql, tcache, link); 259 tcache_stats_merge(tcache, tcache->arena); 260 malloc_mutex_unlock(&tcache->arena->lock); 261 } 262} 263 264tcache_t * 265tcache_get_hard(tcache_t *tcache, bool create) 266{ 267 268 if (tcache == NULL) { 269 if (create == false) { 270 /* 271 * Creating a tcache here would cause 272 * allocation as a side effect of free(). 273 * Ordinarily that would be okay since 274 * tcache_create() failure is a soft failure 275 * that doesn't propagate. However, if TLS 276 * data are freed via free() as in glibc, 277 * subtle corruption could result from setting 278 * a TLS variable after its backing memory is 279 * freed. 280 */ 281 return (NULL); 282 } 283 if (tcache_enabled_get() == false) { 284 tcache_enabled_set(false); /* Memoize. */ 285 return (NULL); 286 } 287 return (tcache_create(choose_arena(NULL))); 288 } 289 if (tcache == TCACHE_STATE_PURGATORY) { 290 /* 291 * Make a note that an allocator function was called 292 * after tcache_thread_cleanup() was called. 293 */ 294 tcache = TCACHE_STATE_REINCARNATED; 295 tcache_tsd_set(&tcache); 296 return (NULL); 297 } 298 if (tcache == TCACHE_STATE_REINCARNATED) 299 return (NULL); 300 not_reached(); 301 return (NULL); 302} 303 304tcache_t * 305tcache_create(arena_t *arena) 306{ 307 tcache_t *tcache; 308 size_t size, stack_offset; 309 unsigned i; 310 311 size = offsetof(tcache_t, tbins) + (sizeof(tcache_bin_t) * nhbins); 312 /* Naturally align the pointer stacks. */ 313 size = PTR_CEILING(size); 314 stack_offset = size; 315 size += stack_nelms * sizeof(void *); 316 /* 317 * Round up to the nearest multiple of the cacheline size, in order to 318 * avoid the possibility of false cacheline sharing. 319 * 320 * That this works relies on the same logic as in ipalloc(), but we 321 * cannot directly call ipalloc() here due to tcache bootstrapping 322 * issues. 323 */ 324 size = (size + CACHELINE_MASK) & (-CACHELINE); 325 326 if (size <= SMALL_MAXCLASS) 327 tcache = (tcache_t *)arena_malloc_small(arena, size, true); 328 else if (size <= tcache_maxclass) 329 tcache = (tcache_t *)arena_malloc_large(arena, size, true); 330 else 331 tcache = (tcache_t *)icalloct(size, false, arena); 332 333 if (tcache == NULL) 334 return (NULL); 335 336 tcache_arena_associate(tcache, arena); 337 338 assert((TCACHE_NSLOTS_SMALL_MAX & 1U) == 0); 339 for (i = 0; i < nhbins; i++) { 340 tcache->tbins[i].lg_fill_div = 1; 341 tcache->tbins[i].avail = (void **)((uintptr_t)tcache + 342 (uintptr_t)stack_offset); 343 stack_offset += tcache_bin_info[i].ncached_max * sizeof(void *); 344 } 345 346 tcache_tsd_set(&tcache); 347 348 return (tcache); 349} 350 351void 352tcache_destroy(tcache_t *tcache) 353{ 354 unsigned i; 355 size_t tcache_size; 356 357 tcache_arena_dissociate(tcache); 358 359 for (i = 0; i < NBINS; i++) { 360 tcache_bin_t *tbin = &tcache->tbins[i]; 361 tcache_bin_flush_small(tbin, i, 0, tcache); 362 363 if (config_stats && tbin->tstats.nrequests != 0) { 364 arena_t *arena = tcache->arena; 365 arena_bin_t *bin = &arena->bins[i]; 366 malloc_mutex_lock(&bin->lock); 367 bin->stats.nrequests += tbin->tstats.nrequests; 368 malloc_mutex_unlock(&bin->lock); 369 } 370 } 371 372 for (; i < nhbins; i++) { 373 tcache_bin_t *tbin = &tcache->tbins[i]; 374 tcache_bin_flush_large(tbin, i, 0, tcache); 375 376 if (config_stats && tbin->tstats.nrequests != 0) { 377 arena_t *arena = tcache->arena; 378 malloc_mutex_lock(&arena->lock); 379 arena->stats.nrequests_large += tbin->tstats.nrequests; 380 arena->stats.lstats[i - NBINS].nrequests += 381 tbin->tstats.nrequests; 382 malloc_mutex_unlock(&arena->lock); 383 } 384 } 385 386 if (config_prof && tcache->prof_accumbytes > 0 && 387 arena_prof_accum(tcache->arena, tcache->prof_accumbytes)) 388 prof_idump(); 389 390 tcache_size = arena_salloc(tcache, false); 391 if (tcache_size <= SMALL_MAXCLASS) { 392 arena_chunk_t *chunk = CHUNK_ADDR2BASE(tcache); 393 arena_t *arena = chunk->arena; 394 size_t pageind = ((uintptr_t)tcache - (uintptr_t)chunk) >> 395 LG_PAGE; 396 arena_chunk_map_t *mapelm = arena_mapp_get(chunk, pageind); 397 398 arena_dalloc_bin(arena, chunk, tcache, pageind, mapelm); 399 } else if (tcache_size <= tcache_maxclass) { 400 arena_chunk_t *chunk = CHUNK_ADDR2BASE(tcache); 401 arena_t *arena = chunk->arena; 402 403 arena_dalloc_large(arena, chunk, tcache); 404 } else 405 idalloct(tcache, false); 406} 407 408void 409tcache_thread_cleanup(void *arg) 410{ 411 tcache_t *tcache = *(tcache_t **)arg; 412 413 if (tcache == TCACHE_STATE_DISABLED) { 414 /* Do nothing. */ 415 } else if (tcache == TCACHE_STATE_REINCARNATED) { 416 /* 417 * Another destructor called an allocator function after this 418 * destructor was called. Reset tcache to 419 * TCACHE_STATE_PURGATORY in order to receive another callback. 420 */ 421 tcache = TCACHE_STATE_PURGATORY; 422 tcache_tsd_set(&tcache); 423 } else if (tcache == TCACHE_STATE_PURGATORY) { 424 /* 425 * The previous time this destructor was called, we set the key 426 * to TCACHE_STATE_PURGATORY so that other destructors wouldn't 427 * cause re-creation of the tcache. This time, do nothing, so 428 * that the destructor will not be called again. 429 */ 430 } else if (tcache != NULL) { 431 assert(tcache != TCACHE_STATE_PURGATORY); 432 tcache_destroy(tcache); 433 tcache = TCACHE_STATE_PURGATORY; 434 tcache_tsd_set(&tcache); 435 } 436} 437 438/* Caller must own arena->lock. */ 439void 440tcache_stats_merge(tcache_t *tcache, arena_t *arena) 441{ 442 unsigned i; 443 444 cassert(config_stats); 445 446 /* Merge and reset tcache stats. */ 447 for (i = 0; i < NBINS; i++) { 448 arena_bin_t *bin = &arena->bins[i]; 449 tcache_bin_t *tbin = &tcache->tbins[i]; 450 malloc_mutex_lock(&bin->lock); 451 bin->stats.nrequests += tbin->tstats.nrequests; 452 malloc_mutex_unlock(&bin->lock); 453 tbin->tstats.nrequests = 0; 454 } 455 456 for (; i < nhbins; i++) { 457 malloc_large_stats_t *lstats = &arena->stats.lstats[i - NBINS]; 458 tcache_bin_t *tbin = &tcache->tbins[i]; 459 arena->stats.nrequests_large += tbin->tstats.nrequests; 460 lstats->nrequests += tbin->tstats.nrequests; 461 tbin->tstats.nrequests = 0; 462 } 463} 464 465bool 466tcache_boot0(void) 467{ 468 unsigned i; 469 470 /* 471 * If necessary, clamp opt_lg_tcache_max, now that arena_maxclass is 472 * known. 473 */ 474 if (opt_lg_tcache_max < 0 || (1U << opt_lg_tcache_max) < SMALL_MAXCLASS) 475 tcache_maxclass = SMALL_MAXCLASS; 476 else if ((1U << opt_lg_tcache_max) > arena_maxclass) 477 tcache_maxclass = arena_maxclass; 478 else 479 tcache_maxclass = (1U << opt_lg_tcache_max); 480 481 nhbins = NBINS + (tcache_maxclass >> LG_PAGE); 482 483 /* Initialize tcache_bin_info. */ 484 tcache_bin_info = (tcache_bin_info_t *)base_alloc(nhbins * 485 sizeof(tcache_bin_info_t)); 486 if (tcache_bin_info == NULL) 487 return (true); 488 stack_nelms = 0; 489 for (i = 0; i < NBINS; i++) { 490 if ((arena_bin_info[i].nregs << 1) <= TCACHE_NSLOTS_SMALL_MAX) { 491 tcache_bin_info[i].ncached_max = 492 (arena_bin_info[i].nregs << 1); 493 } else { 494 tcache_bin_info[i].ncached_max = 495 TCACHE_NSLOTS_SMALL_MAX; 496 } 497 stack_nelms += tcache_bin_info[i].ncached_max; 498 } 499 for (; i < nhbins; i++) { 500 tcache_bin_info[i].ncached_max = TCACHE_NSLOTS_LARGE; 501 stack_nelms += tcache_bin_info[i].ncached_max; 502 } 503 504 return (false); 505} 506 507bool 508tcache_boot1(void) 509{ 510 511 if (tcache_tsd_boot() || tcache_enabled_tsd_boot()) 512 return (true); 513 514 return (false); 515} 516