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 (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 #ifndef _SYS_KMEM_IMPL_H
27 #define _SYS_KMEM_IMPL_H
28
29 #include <sys/kmem.h>
30 #include <sys/vmem.h>
31 #include <sys/thread.h>
32 #include <sys/t_lock.h>
33 #include <sys/time.h>
34 #include <sys/kstat.h>
35 #include <sys/cpuvar.h>
36 #include <sys/systm.h>
37 #include <vm/page.h>
38 #include <sys/avl.h>
39 #include <sys/list.h>
40
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44
45 /*
46 * kernel memory allocator: implementation-private data structures
47 *
48 * Lock order:
49 * 1. cache_lock
50 * 2. cc_lock in order by CPU ID
51 * 3. cache_depot_lock
52 *
53 * Do not call kmem_cache_alloc() or taskq_dispatch() while holding any of the
54 * above locks.
55 */
56
57 #define KMF_AUDIT 0x00000001 /* transaction auditing */
58 #define KMF_DEADBEEF 0x00000002 /* deadbeef checking */
59 #define KMF_REDZONE 0x00000004 /* redzone checking */
60 #define KMF_CONTENTS 0x00000008 /* freed-buffer content logging */
61 #define KMF_STICKY 0x00000010 /* if set, override /etc/system */
62 #define KMF_NOMAGAZINE 0x00000020 /* disable per-cpu magazines */
63 #define KMF_FIREWALL 0x00000040 /* put all bufs before unmapped pages */
64 #define KMF_LITE 0x00000100 /* lightweight debugging */
65
66 #define KMF_HASH 0x00000200 /* cache has hash table */
67 #define KMF_RANDOMIZE 0x00000400 /* randomize other kmem_flags */
68
69 #define KMF_DUMPDIVERT 0x00001000 /* use alternate memory at dump time */
70 #define KMF_DUMPUNSAFE 0x00002000 /* flag caches used at dump time */
71 #define KMF_PREFILL 0x00004000 /* Prefill the slab when created. */
72
73 #define KMF_BUFTAG (KMF_DEADBEEF | KMF_REDZONE)
74 #define KMF_TOUCH (KMF_BUFTAG | KMF_LITE | KMF_CONTENTS)
75 #define KMF_RANDOM (KMF_TOUCH | KMF_AUDIT | KMF_NOMAGAZINE)
76 #define KMF_DEBUG (KMF_RANDOM | KMF_FIREWALL)
77
78 #define KMEM_STACK_DEPTH 15
79
80 #define KMEM_FREE_PATTERN 0xdeadbeefdeadbeefULL
81 #define KMEM_UNINITIALIZED_PATTERN 0xbaddcafebaddcafeULL
82 #define KMEM_REDZONE_PATTERN 0xfeedfacefeedfaceULL
83 #define KMEM_REDZONE_BYTE 0xbb
84
85 /*
86 * Redzone size encodings for kmem_alloc() / kmem_free(). We encode the
87 * allocation size, rather than storing it directly, so that kmem_free()
88 * can distinguish frees of the wrong size from redzone violations.
89 *
90 * A size of zero is never valid.
91 */
92 #define KMEM_SIZE_ENCODE(x) (251 * (x) + 1)
93 #define KMEM_SIZE_DECODE(x) ((x) / 251)
94 #define KMEM_SIZE_VALID(x) ((x) % 251 == 1 && (x) != 1)
95
96
97 #define KMEM_ALIGN 8 /* min guaranteed alignment */
98 #define KMEM_ALIGN_SHIFT 3 /* log2(KMEM_ALIGN) */
99 #define KMEM_VOID_FRACTION 8 /* never waste more than 1/8 of slab */
100
101 #define KMEM_SLAB_IS_PARTIAL(sp) \
102 ((sp)->slab_refcnt > 0 && (sp)->slab_refcnt < (sp)->slab_chunks)
103 #define KMEM_SLAB_IS_ALL_USED(sp) \
104 ((sp)->slab_refcnt == (sp)->slab_chunks)
105
106 /*
107 * The bufctl (buffer control) structure keeps some minimal information
108 * about each buffer: its address, its slab, and its current linkage,
109 * which is either on the slab's freelist (if the buffer is free), or
110 * on the cache's buf-to-bufctl hash table (if the buffer is allocated).
111 * In the case of non-hashed, or "raw", caches (the common case), only
112 * the freelist linkage is necessary: the buffer address is at a fixed
113 * offset from the bufctl address, and the slab is at the end of the page.
114 *
115 * NOTE: bc_next must be the first field; raw buffers have linkage only.
116 */
117 typedef struct kmem_bufctl {
118 struct kmem_bufctl *bc_next; /* next bufctl struct */
119 void *bc_addr; /* address of buffer */
120 struct kmem_slab *bc_slab; /* controlling slab */
121 } kmem_bufctl_t;
122
123 /*
124 * The KMF_AUDIT version of the bufctl structure. The beginning of this
125 * structure must be identical to the normal bufctl structure so that
126 * pointers are interchangeable.
127 */
128 typedef struct kmem_bufctl_audit {
129 struct kmem_bufctl *bc_next; /* next bufctl struct */
130 void *bc_addr; /* address of buffer */
131 struct kmem_slab *bc_slab; /* controlling slab */
132 kmem_cache_t *bc_cache; /* controlling cache */
133 hrtime_t bc_timestamp; /* transaction time */
134 kthread_t *bc_thread; /* thread doing transaction */
135 struct kmem_bufctl *bc_lastlog; /* last log entry */
136 void *bc_contents; /* contents at last free */
137 int bc_depth; /* stack depth */
138 pc_t bc_stack[KMEM_STACK_DEPTH]; /* pc stack */
139 } kmem_bufctl_audit_t;
140
141 /*
142 * A kmem_buftag structure is appended to each buffer whenever any of the
143 * KMF_BUFTAG flags (KMF_DEADBEEF, KMF_REDZONE, KMF_VERIFY) are set.
144 */
145 typedef struct kmem_buftag {
146 uint64_t bt_redzone; /* 64-bit redzone pattern */
147 kmem_bufctl_t *bt_bufctl; /* bufctl */
148 intptr_t bt_bxstat; /* bufctl ^ (alloc/free) */
149 } kmem_buftag_t;
150
151 /*
152 * A variant of the kmem_buftag structure used for KMF_LITE caches.
153 * Previous callers are stored in reverse chronological order. (i.e. most
154 * recent first)
155 */
156 typedef struct kmem_buftag_lite {
157 kmem_buftag_t bt_buftag; /* a normal buftag */
158 pc_t bt_history[1]; /* zero or more callers */
159 } kmem_buftag_lite_t;
160
161 #define KMEM_BUFTAG_LITE_SIZE(f) \
162 (offsetof(kmem_buftag_lite_t, bt_history[f]))
163
164 #define KMEM_BUFTAG(cp, buf) \
165 ((kmem_buftag_t *)((char *)(buf) + (cp)->cache_buftag))
166
167 #define KMEM_BUFCTL(cp, buf) \
168 ((kmem_bufctl_t *)((char *)(buf) + (cp)->cache_bufctl))
169
170 #define KMEM_BUF(cp, bcp) \
171 ((void *)((char *)(bcp) - (cp)->cache_bufctl))
172
173 #define KMEM_SLAB(cp, buf) \
174 ((kmem_slab_t *)P2END((uintptr_t)(buf), (cp)->cache_slabsize) - 1)
175
176 /*
177 * Test for using alternate memory at dump time.
178 */
179 #define KMEM_DUMP(cp) ((cp)->cache_flags & KMF_DUMPDIVERT)
180 #define KMEM_DUMPCC(ccp) ((ccp)->cc_flags & KMF_DUMPDIVERT)
181
182 /*
183 * The "CPU" macro loads a cpu_t that refers to the cpu that the current
184 * thread is running on at the time the macro is executed. A context switch
185 * may occur immediately after loading this data structure, leaving this
186 * thread pointing at the cpu_t for the previous cpu. This is not a problem;
187 * we'd just end up checking the previous cpu's per-cpu cache, and then check
188 * the other layers of the kmem cache if need be.
189 *
190 * It's not even a problem if the old cpu gets DR'ed out during the context
191 * switch. The cpu-remove DR operation bzero()s the cpu_t, but doesn't free
192 * it. So the cpu_t's cpu_cache_offset would read as 0, causing us to use
193 * cpu 0's per-cpu cache.
194 *
195 * So, there is no need to disable kernel preemption while using the CPU macro
196 * below since if we have been context switched, there will not be any
197 * correctness problem, just a momentary use of a different per-cpu cache.
198 */
199
200 #define KMEM_CPU_CACHE(cp) \
201 ((kmem_cpu_cache_t *)((char *)(&cp->cache_cpu) + CPU->cpu_cache_offset))
202
203 #define KMEM_MAGAZINE_VALID(cp, mp) \
204 (((kmem_slab_t *)P2END((uintptr_t)(mp), PAGESIZE) - 1)->slab_cache == \
205 (cp)->cache_magtype->mt_cache)
206
207 #define KMEM_SLAB_OFFSET(sp, buf) \
208 ((size_t)((uintptr_t)(buf) - (uintptr_t)((sp)->slab_base)))
209
210 #define KMEM_SLAB_MEMBER(sp, buf) \
211 (KMEM_SLAB_OFFSET(sp, buf) < (sp)->slab_cache->cache_slabsize)
212
213 #define KMEM_BUFTAG_ALLOC 0xa110c8edUL
214 #define KMEM_BUFTAG_FREE 0xf4eef4eeUL
215
216 /* slab_later_count thresholds */
217 #define KMEM_DISBELIEF 3
218
219 /* slab_flags */
220 #define KMEM_SLAB_NOMOVE 0x1
221 #define KMEM_SLAB_MOVE_PENDING 0x2
222
223 typedef struct kmem_slab {
224 struct kmem_cache *slab_cache; /* controlling cache */
225 void *slab_base; /* base of allocated memory */
226 avl_node_t slab_link; /* slab linkage */
227 struct kmem_bufctl *slab_head; /* first free buffer */
228 long slab_refcnt; /* outstanding allocations */
229 long slab_chunks; /* chunks (bufs) in this slab */
230 uint32_t slab_stuck_offset; /* unmoved buffer offset */
231 uint16_t slab_later_count; /* cf KMEM_CBRC_LATER */
232 uint16_t slab_flags; /* bits to mark the slab */
233 } kmem_slab_t;
234
235 #define KMEM_HASH_INITIAL 64
236
237 #define KMEM_HASH(cp, buf) \
238 ((cp)->cache_hash_table + \
239 (((uintptr_t)(buf) >> (cp)->cache_hash_shift) & (cp)->cache_hash_mask))
240
241 typedef struct kmem_magazine {
242 void *mag_next;
243 void *mag_round[1]; /* one or more rounds */
244 } kmem_magazine_t;
245
246 /*
247 * The magazine types for fast per-cpu allocation
248 */
249 typedef struct kmem_magtype {
250 short mt_magsize; /* magazine size (number of rounds) */
251 int mt_align; /* magazine alignment */
252 size_t mt_minbuf; /* all smaller buffers qualify */
253 size_t mt_maxbuf; /* no larger buffers qualify */
254 kmem_cache_t *mt_cache; /* magazine cache */
255 } kmem_magtype_t;
256
257 #define KMEM_CPU_CACHE_SIZE 64 /* must be power of 2 */
258 #define KMEM_CPU_PAD (KMEM_CPU_CACHE_SIZE - sizeof (kmutex_t) - \
259 2 * sizeof (uint64_t) - 2 * sizeof (void *) - sizeof (int) - \
260 5 * sizeof (short))
261 #define KMEM_CACHE_SIZE(ncpus) \
262 ((size_t)(&((kmem_cache_t *)0)->cache_cpu[ncpus]))
263
264 /* Offset from kmem_cache->cache_cpu for per cpu caches */
265 #define KMEM_CPU_CACHE_OFFSET(cpuid) \
266 ((size_t)(&((kmem_cache_t *)0)->cache_cpu[cpuid]) - \
267 (size_t)(&((kmem_cache_t *)0)->cache_cpu))
268
269 typedef struct kmem_cpu_cache {
270 kmutex_t cc_lock; /* protects this cpu's local cache */
271 uint64_t cc_alloc; /* allocations from this cpu */
272 uint64_t cc_free; /* frees to this cpu */
273 kmem_magazine_t *cc_loaded; /* the currently loaded magazine */
274 kmem_magazine_t *cc_ploaded; /* the previously loaded magazine */
275 int cc_flags; /* CPU-local copy of cache_flags */
276 short cc_rounds; /* number of objects in loaded mag */
277 short cc_prounds; /* number of objects in previous mag */
278 short cc_magsize; /* number of rounds in a full mag */
279 short cc_dump_rounds; /* dump time copy of cc_rounds */
280 short cc_dump_prounds; /* dump time copy of cc_prounds */
281 char cc_pad[KMEM_CPU_PAD]; /* for nice alignment */
282 } kmem_cpu_cache_t;
283
284 /*
285 * The magazine lists used in the depot.
286 */
287 typedef struct kmem_maglist {
288 kmem_magazine_t *ml_list; /* magazine list */
289 long ml_total; /* number of magazines */
290 long ml_min; /* min since last update */
291 long ml_reaplimit; /* max reapable magazines */
292 uint64_t ml_alloc; /* allocations from this list */
293 } kmem_maglist_t;
294
295 typedef struct kmem_defrag {
296 /*
297 * Statistics
298 */
299 uint64_t kmd_callbacks; /* move callbacks */
300 uint64_t kmd_yes; /* KMEM_CBRC_YES responses */
301 uint64_t kmd_no; /* NO responses */
302 uint64_t kmd_later; /* LATER responses */
303 uint64_t kmd_dont_need; /* DONT_NEED responses */
304 uint64_t kmd_dont_know; /* DONT_KNOW responses */
305 uint64_t kmd_slabs_freed; /* slabs freed by moves */
306 uint64_t kmd_defrags; /* kmem_cache_defrag() */
307 uint64_t kmd_scans; /* kmem_cache_scan() */
308
309 /*
310 * Consolidator fields
311 */
312 avl_tree_t kmd_moves_pending; /* buffer moves pending */
313 list_t kmd_deadlist; /* deferred slab frees */
314 size_t kmd_deadcount; /* # of slabs in kmd_deadlist */
315 uint8_t kmd_reclaim_numer; /* slab usage threshold */
316 uint8_t kmd_pad1; /* compiler padding */
317 uint16_t kmd_consolidate; /* triggers consolidator */
318 uint32_t kmd_pad2; /* compiler padding */
319 size_t kmd_slabs_sought; /* reclaimable slabs sought */
320 size_t kmd_slabs_found; /* reclaimable slabs found */
321 size_t kmd_tries; /* nth scan interval counter */
322 /*
323 * Fields used to ASSERT that the client does not kmem_cache_free()
324 * objects passed to the move callback.
325 */
326 void *kmd_from_buf; /* object to move */
327 void *kmd_to_buf; /* move destination */
328 kthread_t *kmd_thread; /* thread calling move */
329 } kmem_defrag_t;
330
331 #define KMEM_CACHE_NAMELEN 31
332
333 struct kmem_cache {
334 /*
335 * Statistics
336 */
337 uint64_t cache_slab_create; /* slab creates */
338 uint64_t cache_slab_destroy; /* slab destroys */
339 uint64_t cache_slab_alloc; /* slab layer allocations */
340 uint64_t cache_slab_free; /* slab layer frees */
341 uint64_t cache_alloc_fail; /* total failed allocations */
342 uint64_t cache_buftotal; /* total buffers */
343 uint64_t cache_bufmax; /* max buffers ever */
344 uint64_t cache_bufslab; /* buffers free in slab layer */
345 uint64_t cache_reap; /* cache reaps */
346 uint64_t cache_rescale; /* hash table rescales */
347 uint64_t cache_lookup_depth; /* hash lookup depth */
348 uint64_t cache_depot_contention; /* mutex contention count */
349 uint64_t cache_depot_contention_prev; /* previous snapshot */
350
351 /*
352 * Cache properties
353 */
354 char cache_name[KMEM_CACHE_NAMELEN + 1];
355 size_t cache_bufsize; /* object size */
356 size_t cache_align; /* object alignment */
357 int (*cache_constructor)(void *, void *, int);
358 void (*cache_destructor)(void *, void *);
359 void (*cache_reclaim)(void *);
360 kmem_cbrc_t (*cache_move)(void *, void *, size_t, void *);
361 void *cache_private; /* opaque arg to callbacks */
362 vmem_t *cache_arena; /* vmem source for slabs */
363 int cache_cflags; /* cache creation flags */
364 int cache_flags; /* various cache state info */
365 uint32_t cache_mtbf; /* induced alloc failure rate */
366 uint32_t cache_pad1; /* compiler padding */
367 kstat_t *cache_kstat; /* exported statistics */
368 list_node_t cache_link; /* cache linkage */
369
370 /*
371 * Slab layer
372 */
373 kmutex_t cache_lock; /* protects slab layer */
374 size_t cache_chunksize; /* buf + alignment [+ debug] */
375 size_t cache_slabsize; /* size of a slab */
376 size_t cache_maxchunks; /* max buffers per slab */
377 size_t cache_bufctl; /* buf-to-bufctl distance */
378 size_t cache_buftag; /* buf-to-buftag distance */
379 size_t cache_verify; /* bytes to verify */
380 size_t cache_contents; /* bytes of saved content */
381 size_t cache_color; /* next slab color */
382 size_t cache_mincolor; /* maximum slab color */
383 size_t cache_maxcolor; /* maximum slab color */
384 size_t cache_hash_shift; /* get to interesting bits */
385 size_t cache_hash_mask; /* hash table mask */
386 list_t cache_complete_slabs; /* completely allocated slabs */
387 size_t cache_complete_slab_count;
388 avl_tree_t cache_partial_slabs; /* partial slab freelist */
389 size_t cache_partial_binshift; /* for AVL sort bins */
390 kmem_cache_t *cache_bufctl_cache; /* source of bufctls */
391 kmem_bufctl_t **cache_hash_table; /* hash table base */
392 kmem_defrag_t *cache_defrag; /* slab consolidator fields */
393
394 /*
395 * Depot layer
396 */
397 kmutex_t cache_depot_lock; /* protects depot */
398 kmem_magtype_t *cache_magtype; /* magazine type */
399 kmem_maglist_t cache_full; /* full magazines */
400 kmem_maglist_t cache_empty; /* empty magazines */
401 void *cache_dumpfreelist; /* heap during crash dump */
402 void *cache_dumplog; /* log entry during dump */
403
404 /*
405 * Per-CPU layer
406 */
407 kmem_cpu_cache_t cache_cpu[1]; /* max_ncpus actual elements */
408 };
409
410 typedef struct kmem_cpu_log_header {
411 kmutex_t clh_lock;
412 char *clh_current;
413 size_t clh_avail;
414 int clh_chunk;
415 int clh_hits;
416 char clh_pad[64 - sizeof (kmutex_t) - sizeof (char *) -
417 sizeof (size_t) - 2 * sizeof (int)];
418 } kmem_cpu_log_header_t;
419
420 typedef struct kmem_log_header {
421 kmutex_t lh_lock;
422 char *lh_base;
423 int *lh_free;
424 size_t lh_chunksize;
425 int lh_nchunks;
426 int lh_head;
427 int lh_tail;
428 int lh_hits;
429 kmem_cpu_log_header_t lh_cpu[1]; /* ncpus actually allocated */
430 } kmem_log_header_t;
431
432 /* kmem_move kmm_flags */
433 #define KMM_DESPERATE 0x1
434 #define KMM_NOTIFY 0x2
435 #define KMM_DEBUG 0x4
436
437 typedef struct kmem_move {
438 kmem_slab_t *kmm_from_slab;
439 void *kmm_from_buf;
440 void *kmm_to_buf;
441 avl_node_t kmm_entry;
442 int kmm_flags;
443 } kmem_move_t;
444
445 /*
446 * In order to consolidate partial slabs, it must be possible for the cache to
447 * have partial slabs.
448 */
449 #define KMEM_IS_MOVABLE(cp) \
450 (((cp)->cache_chunksize * 2) <= (cp)->cache_slabsize)
451
452 #ifdef __cplusplus
453 }
454 #endif
455
456 #endif /* _SYS_KMEM_IMPL_H */