1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #ifndef _SYS_KMEM_IMPL_H 28 #define _SYS_KMEM_IMPL_H 29 30 #include <sys/kmem.h> 31 #include <sys/vmem.h> 32 #include <sys/thread.h> 33 #include <sys/t_lock.h> 34 #include <sys/time.h> 35 #include <sys/kstat.h> 36 #include <sys/cpuvar.h> 37 #include <sys/systm.h> 38 #include <vm/page.h> 39 #include <sys/avl.h> 40 #include <sys/list.h> 41 42 #ifdef __cplusplus 43 extern "C" { 44 #endif 45 46 /* 47 * kernel memory allocator: implementation-private data structures 48 * 49 * Lock order: 50 * 1. cache_lock 51 * 2. cc_lock in order by CPU ID 52 * 3. cache_depot_lock 53 * 54 * Do not call kmem_cache_alloc() or taskq_dispatch() while holding any of the 55 * above locks. 56 */ 57 58 #define KMF_AUDIT 0x00000001 /* transaction auditing */ 59 #define KMF_DEADBEEF 0x00000002 /* deadbeef checking */ 60 #define KMF_REDZONE 0x00000004 /* redzone checking */ 61 #define KMF_CONTENTS 0x00000008 /* freed-buffer content logging */ 62 #define KMF_STICKY 0x00000010 /* if set, override /etc/system */ 63 #define KMF_NOMAGAZINE 0x00000020 /* disable per-cpu magazines */ 64 #define KMF_FIREWALL 0x00000040 /* put all bufs before unmapped pages */ 65 #define KMF_LITE 0x00000100 /* lightweight debugging */ 66 67 #define KMF_HASH 0x00000200 /* cache has hash table */ 68 #define KMF_RANDOMIZE 0x00000400 /* randomize other kmem_flags */ 69 70 #define KMF_BUFTAG (KMF_DEADBEEF | KMF_REDZONE) 71 #define KMF_TOUCH (KMF_BUFTAG | KMF_LITE | KMF_CONTENTS) 72 #define KMF_RANDOM (KMF_TOUCH | KMF_AUDIT | KMF_NOMAGAZINE) 73 #define KMF_DEBUG (KMF_RANDOM | KMF_FIREWALL) 74 75 #define KMEM_STACK_DEPTH 15 76 77 #define KMEM_FREE_PATTERN 0xdeadbeefdeadbeefULL 78 #define KMEM_UNINITIALIZED_PATTERN 0xbaddcafebaddcafeULL 79 #define KMEM_REDZONE_PATTERN 0xfeedfacefeedfaceULL 80 #define KMEM_REDZONE_BYTE 0xbb 81 82 /* 83 * Redzone size encodings for kmem_alloc() / kmem_free(). We encode the 84 * allocation size, rather than storing it directly, so that kmem_free() 85 * can distinguish frees of the wrong size from redzone violations. 86 * 87 * A size of zero is never valid. 88 */ 89 #define KMEM_SIZE_ENCODE(x) (251 * (x) + 1) 90 #define KMEM_SIZE_DECODE(x) ((x) / 251) 91 #define KMEM_SIZE_VALID(x) ((x) % 251 == 1 && (x) != 1) 92 93 94 #define KMEM_ALIGN 8 /* min guaranteed alignment */ 95 #define KMEM_ALIGN_SHIFT 3 /* log2(KMEM_ALIGN) */ 96 #define KMEM_VOID_FRACTION 8 /* never waste more than 1/8 of slab */ 97 98 #define KMEM_SLAB_IS_PARTIAL(sp) \ 99 ((sp)->slab_refcnt > 0 && (sp)->slab_refcnt < (sp)->slab_chunks) 100 #define KMEM_SLAB_IS_ALL_USED(sp) \ 101 ((sp)->slab_refcnt == (sp)->slab_chunks) 102 103 /* 104 * The bufctl (buffer control) structure keeps some minimal information 105 * about each buffer: its address, its slab, and its current linkage, 106 * which is either on the slab's freelist (if the buffer is free), or 107 * on the cache's buf-to-bufctl hash table (if the buffer is allocated). 108 * In the case of non-hashed, or "raw", caches (the common case), only 109 * the freelist linkage is necessary: the buffer address is at a fixed 110 * offset from the bufctl address, and the slab is at the end of the page. 111 * 112 * NOTE: bc_next must be the first field; raw buffers have linkage only. 113 */ 114 typedef struct kmem_bufctl { 115 struct kmem_bufctl *bc_next; /* next bufctl struct */ 116 void *bc_addr; /* address of buffer */ 117 struct kmem_slab *bc_slab; /* controlling slab */ 118 } kmem_bufctl_t; 119 120 /* 121 * The KMF_AUDIT version of the bufctl structure. The beginning of this 122 * structure must be identical to the normal bufctl structure so that 123 * pointers are interchangeable. 124 */ 125 typedef struct kmem_bufctl_audit { 126 struct kmem_bufctl *bc_next; /* next bufctl struct */ 127 void *bc_addr; /* address of buffer */ 128 struct kmem_slab *bc_slab; /* controlling slab */ 129 kmem_cache_t *bc_cache; /* controlling cache */ 130 hrtime_t bc_timestamp; /* transaction time */ 131 kthread_t *bc_thread; /* thread doing transaction */ 132 struct kmem_bufctl *bc_lastlog; /* last log entry */ 133 void *bc_contents; /* contents at last free */ 134 int bc_depth; /* stack depth */ 135 pc_t bc_stack[KMEM_STACK_DEPTH]; /* pc stack */ 136 } kmem_bufctl_audit_t; 137 138 /* 139 * A kmem_buftag structure is appended to each buffer whenever any of the 140 * KMF_BUFTAG flags (KMF_DEADBEEF, KMF_REDZONE, KMF_VERIFY) are set. 141 */ 142 typedef struct kmem_buftag { 143 uint64_t bt_redzone; /* 64-bit redzone pattern */ 144 kmem_bufctl_t *bt_bufctl; /* bufctl */ 145 intptr_t bt_bxstat; /* bufctl ^ (alloc/free) */ 146 } kmem_buftag_t; 147 148 /* 149 * A variant of the kmem_buftag structure used for KMF_LITE caches. 150 * Previous callers are stored in reverse chronological order. (i.e. most 151 * recent first) 152 */ 153 typedef struct kmem_buftag_lite { 154 kmem_buftag_t bt_buftag; /* a normal buftag */ 155 pc_t bt_history[1]; /* zero or more callers */ 156 } kmem_buftag_lite_t; 157 158 #define KMEM_BUFTAG_LITE_SIZE(f) \ 159 (offsetof(kmem_buftag_lite_t, bt_history[f])) 160 161 #define KMEM_BUFTAG(cp, buf) \ 162 ((kmem_buftag_t *)((char *)(buf) + (cp)->cache_buftag)) 163 164 #define KMEM_BUFCTL(cp, buf) \ 165 ((kmem_bufctl_t *)((char *)(buf) + (cp)->cache_bufctl)) 166 167 #define KMEM_BUF(cp, bcp) \ 168 ((void *)((char *)(bcp) - (cp)->cache_bufctl)) 169 170 #define KMEM_SLAB(cp, buf) \ 171 ((kmem_slab_t *)P2END((uintptr_t)(buf), (cp)->cache_slabsize) - 1) 172 173 /* 174 * The "CPU" macro loads a cpu_t that refers to the cpu that the current 175 * thread is running on at the time the macro is executed. A context switch 176 * may occur immediately after loading this data structure, leaving this 177 * thread pointing at the cpu_t for the previous cpu. This is not a problem; 178 * we'd just end up checking the previous cpu's per-cpu cache, and then check 179 * the other layers of the kmem cache if need be. 180 * 181 * It's not even a problem if the old cpu gets DR'ed out during the context 182 * switch. The cpu-remove DR operation bzero()s the cpu_t, but doesn't free 183 * it. So the cpu_t's cpu_cache_offset would read as 0, causing us to use 184 * cpu 0's per-cpu cache. 185 * 186 * So, there is no need to disable kernel preemption while using the CPU macro 187 * below since if we have been context switched, there will not be any 188 * correctness problem, just a momentary use of a different per-cpu cache. 189 */ 190 191 #define KMEM_CPU_CACHE(cp) \ 192 (kmem_cpu_cache_t *)((char *)(&cp->cache_cpu) + CPU->cpu_cache_offset) 193 194 #define KMEM_MAGAZINE_VALID(cp, mp) \ 195 (((kmem_slab_t *)P2END((uintptr_t)(mp), PAGESIZE) - 1)->slab_cache == \ 196 (cp)->cache_magtype->mt_cache) 197 198 #define KMEM_SLAB_OFFSET(sp, buf) \ 199 ((size_t)((uintptr_t)(buf) - (uintptr_t)((sp)->slab_base))) 200 201 #define KMEM_SLAB_MEMBER(sp, buf) \ 202 (KMEM_SLAB_OFFSET(sp, buf) < (sp)->slab_cache->cache_slabsize) 203 204 #define KMEM_BUFTAG_ALLOC 0xa110c8edUL 205 #define KMEM_BUFTAG_FREE 0xf4eef4eeUL 206 207 /* slab_later_count thresholds */ 208 #define KMEM_DISBELIEF 3 209 210 /* slab_flags */ 211 #define KMEM_SLAB_NOMOVE 0x1 212 #define KMEM_SLAB_MOVE_PENDING 0x2 213 214 typedef struct kmem_slab { 215 struct kmem_cache *slab_cache; /* controlling cache */ 216 void *slab_base; /* base of allocated memory */ 217 avl_node_t slab_link; /* slab linkage */ 218 struct kmem_bufctl *slab_head; /* first free buffer */ 219 long slab_refcnt; /* outstanding allocations */ 220 long slab_chunks; /* chunks (bufs) in this slab */ 221 uint32_t slab_stuck_offset; /* unmoved buffer offset */ 222 uint16_t slab_later_count; /* cf KMEM_CBRC_LATER */ 223 uint16_t slab_flags; /* bits to mark the slab */ 224 } kmem_slab_t; 225 226 #define KMEM_HASH_INITIAL 64 227 228 #define KMEM_HASH(cp, buf) \ 229 ((cp)->cache_hash_table + \ 230 (((uintptr_t)(buf) >> (cp)->cache_hash_shift) & (cp)->cache_hash_mask)) 231 232 typedef struct kmem_magazine { 233 void *mag_next; 234 void *mag_round[1]; /* one or more rounds */ 235 } kmem_magazine_t; 236 237 /* 238 * The magazine types for fast per-cpu allocation 239 */ 240 typedef struct kmem_magtype { 241 int mt_magsize; /* magazine size (number of rounds) */ 242 int mt_align; /* magazine alignment */ 243 size_t mt_minbuf; /* all smaller buffers qualify */ 244 size_t mt_maxbuf; /* no larger buffers qualify */ 245 kmem_cache_t *mt_cache; /* magazine cache */ 246 } kmem_magtype_t; 247 248 #define KMEM_CPU_CACHE_SIZE 64 /* must be power of 2 */ 249 #define KMEM_CPU_PAD (KMEM_CPU_CACHE_SIZE - sizeof (kmutex_t) - \ 250 2 * sizeof (uint64_t) - 2 * sizeof (void *) - 4 * sizeof (int)) 251 #define KMEM_CACHE_SIZE(ncpus) \ 252 ((size_t)(&((kmem_cache_t *)0)->cache_cpu[ncpus])) 253 254 /* Offset from kmem_cache->cache_cpu for per cpu caches */ 255 #define KMEM_CPU_CACHE_OFFSET(cpuid) \ 256 ((size_t)(&((kmem_cache_t *)0)->cache_cpu[cpuid]) - \ 257 (size_t)(&((kmem_cache_t *)0)->cache_cpu)) 258 259 typedef struct kmem_cpu_cache { 260 kmutex_t cc_lock; /* protects this cpu's local cache */ 261 uint64_t cc_alloc; /* allocations from this cpu */ 262 uint64_t cc_free; /* frees to this cpu */ 263 kmem_magazine_t *cc_loaded; /* the currently loaded magazine */ 264 kmem_magazine_t *cc_ploaded; /* the previously loaded magazine */ 265 int cc_rounds; /* number of objects in loaded mag */ 266 int cc_prounds; /* number of objects in previous mag */ 267 int cc_magsize; /* number of rounds in a full mag */ 268 int cc_flags; /* CPU-local copy of cache_flags */ 269 char cc_pad[KMEM_CPU_PAD]; /* for nice alignment */ 270 } kmem_cpu_cache_t; 271 272 /* 273 * The magazine lists used in the depot. 274 */ 275 typedef struct kmem_maglist { 276 kmem_magazine_t *ml_list; /* magazine list */ 277 long ml_total; /* number of magazines */ 278 long ml_min; /* min since last update */ 279 long ml_reaplimit; /* max reapable magazines */ 280 uint64_t ml_alloc; /* allocations from this list */ 281 } kmem_maglist_t; 282 283 typedef struct kmem_defrag { 284 /* 285 * Statistics 286 */ 287 uint64_t kmd_callbacks; /* move callbacks */ 288 uint64_t kmd_yes; /* KMEM_CBRC_YES responses */ 289 uint64_t kmd_no; /* NO responses */ 290 uint64_t kmd_later; /* LATER responses */ 291 uint64_t kmd_dont_need; /* DONT_NEED responses */ 292 uint64_t kmd_dont_know; /* DONT_KNOW responses */ 293 uint64_t kmd_hunt_found; /* DONT_KNOW: # found in mag */ 294 295 /* 296 * Consolidator fields 297 */ 298 avl_tree_t kmd_moves_pending; /* buffer moves pending */ 299 list_t kmd_deadlist; /* deferred slab frees */ 300 size_t kmd_deadcount; /* # of slabs in kmd_deadlist */ 301 uint8_t kmd_reclaim_numer; /* slab usage threshold */ 302 uint8_t kmd_pad1; /* compiler padding */ 303 size_t kmd_slabs_sought; /* reclaimable slabs sought */ 304 size_t kmd_slabs_found; /* reclaimable slabs found */ 305 size_t kmd_scans; /* nth scan interval counter */ 306 /* 307 * Fields used to ASSERT that the client does not kmem_cache_free() 308 * objects passed to the move callback. 309 */ 310 void *kmd_from_buf; /* object to move */ 311 void *kmd_to_buf; /* move destination */ 312 kthread_t *kmd_thread; /* thread calling move */ 313 } kmem_defrag_t; 314 315 #define KMEM_CACHE_NAMELEN 31 316 317 struct kmem_cache { 318 /* 319 * Statistics 320 */ 321 uint64_t cache_slab_create; /* slab creates */ 322 uint64_t cache_slab_destroy; /* slab destroys */ 323 uint64_t cache_slab_alloc; /* slab layer allocations */ 324 uint64_t cache_slab_free; /* slab layer frees */ 325 uint64_t cache_alloc_fail; /* total failed allocations */ 326 uint64_t cache_buftotal; /* total buffers */ 327 uint64_t cache_bufmax; /* max buffers ever */ 328 uint64_t cache_bufslab; /* buffers free in slab layer */ 329 uint64_t cache_rescale; /* # of hash table rescales */ 330 uint64_t cache_lookup_depth; /* hash lookup depth */ 331 uint64_t cache_depot_contention; /* mutex contention count */ 332 uint64_t cache_depot_contention_prev; /* previous snapshot */ 333 334 /* 335 * Cache properties 336 */ 337 char cache_name[KMEM_CACHE_NAMELEN + 1]; 338 size_t cache_bufsize; /* object size */ 339 size_t cache_align; /* object alignment */ 340 int (*cache_constructor)(void *, void *, int); 341 void (*cache_destructor)(void *, void *); 342 void (*cache_reclaim)(void *); 343 kmem_cbrc_t (*cache_move)(void *, void *, size_t, void *); 344 void *cache_private; /* opaque arg to callbacks */ 345 vmem_t *cache_arena; /* vmem source for slabs */ 346 int cache_cflags; /* cache creation flags */ 347 int cache_flags; /* various cache state info */ 348 uint32_t cache_mtbf; /* induced alloc failure rate */ 349 uint32_t cache_pad1; /* compiler padding */ 350 kstat_t *cache_kstat; /* exported statistics */ 351 list_node_t cache_link; /* cache linkage */ 352 353 /* 354 * Slab layer 355 */ 356 kmutex_t cache_lock; /* protects slab layer */ 357 size_t cache_chunksize; /* buf + alignment [+ debug] */ 358 size_t cache_slabsize; /* size of a slab */ 359 size_t cache_maxchunks; /* max buffers per slab */ 360 size_t cache_bufctl; /* buf-to-bufctl distance */ 361 size_t cache_buftag; /* buf-to-buftag distance */ 362 size_t cache_verify; /* bytes to verify */ 363 size_t cache_contents; /* bytes of saved content */ 364 size_t cache_color; /* next slab color */ 365 size_t cache_mincolor; /* maximum slab color */ 366 size_t cache_maxcolor; /* maximum slab color */ 367 size_t cache_hash_shift; /* get to interesting bits */ 368 size_t cache_hash_mask; /* hash table mask */ 369 list_t cache_complete_slabs; /* completely allocated slabs */ 370 size_t cache_complete_slab_count; 371 avl_tree_t cache_partial_slabs; /* partial slab freelist */ 372 size_t cache_partial_binshift; /* for AVL sort bins */ 373 kmem_cache_t *cache_bufctl_cache; /* source of bufctls */ 374 kmem_bufctl_t **cache_hash_table; /* hash table base */ 375 kmem_defrag_t *cache_defrag; /* slab consolidator fields */ 376 377 /* 378 * Depot layer 379 */ 380 kmutex_t cache_depot_lock; /* protects depot */ 381 kmem_magtype_t *cache_magtype; /* magazine type */ 382 kmem_maglist_t cache_full; /* full magazines */ 383 kmem_maglist_t cache_empty; /* empty magazines */ 384 385 /* 386 * Per-CPU layer 387 */ 388 kmem_cpu_cache_t cache_cpu[1]; /* max_ncpus actual elements */ 389 }; 390 391 typedef struct kmem_cpu_log_header { 392 kmutex_t clh_lock; 393 char *clh_current; 394 size_t clh_avail; 395 int clh_chunk; 396 int clh_hits; 397 char clh_pad[64 - sizeof (kmutex_t) - sizeof (char *) - 398 sizeof (size_t) - 2 * sizeof (int)]; 399 } kmem_cpu_log_header_t; 400 401 typedef struct kmem_log_header { 402 kmutex_t lh_lock; 403 char *lh_base; 404 int *lh_free; 405 size_t lh_chunksize; 406 int lh_nchunks; 407 int lh_head; 408 int lh_tail; 409 int lh_hits; 410 kmem_cpu_log_header_t lh_cpu[1]; /* ncpus actually allocated */ 411 } kmem_log_header_t; 412 413 /* kmem_move kmm_flags */ 414 #define KMM_DESPERATE 0x1 415 #define KMM_NOTIFY 0x2 416 417 typedef struct kmem_move { 418 kmem_slab_t *kmm_from_slab; 419 void *kmm_from_buf; 420 void *kmm_to_buf; 421 avl_node_t kmm_entry; 422 int kmm_flags; 423 } kmem_move_t; 424 425 /* 426 * In order to consolidate partial slabs, it must be possible for the cache to 427 * have partial slabs. 428 */ 429 #define KMEM_IS_MOVABLE(cp) \ 430 (((cp)->cache_chunksize * 2) <= (cp)->cache_slabsize) 431 432 #ifdef __cplusplus 433 } 434 #endif 435 436 #endif /* _SYS_KMEM_IMPL_H */ 437