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 * Copyright 2018 Joyent, Inc.
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_DUMPDIVERT 0x00001000 /* use alternate memory at dump time */
71 #define KMF_DUMPUNSAFE 0x00002000 /* flag caches used at dump time */
72 #define KMF_PREFILL 0x00004000 /* Prefill the slab when created. */
73
74 #define KMF_BUFTAG (KMF_DEADBEEF | KMF_REDZONE)
75 #define KMF_TOUCH (KMF_BUFTAG | KMF_LITE | KMF_CONTENTS)
76 #define KMF_RANDOM (KMF_TOUCH | KMF_AUDIT | KMF_NOMAGAZINE)
77 #define KMF_DEBUG (KMF_RANDOM | KMF_FIREWALL)
78
79 #define KMEM_STACK_DEPTH 15
80
81 #define KMEM_FREE_PATTERN 0xdeadbeefdeadbeefULL
82 #define KMEM_UNINITIALIZED_PATTERN 0xbaddcafebaddcafeULL
83 #define KMEM_REDZONE_PATTERN 0xfeedfacefeedfaceULL
84 #define KMEM_REDZONE_BYTE 0xbb
85
86 /*
87 * Redzone size encodings for kmem_alloc() / kmem_free(). We encode the
88 * allocation size, rather than storing it directly, so that kmem_free()
89 * can distinguish frees of the wrong size from redzone violations.
90 *
91 * A size of zero is never valid.
92 */
93 #define KMEM_SIZE_ENCODE(x) (251 * (x) + 1)
94 #define KMEM_SIZE_DECODE(x) ((x) / 251)
95 #define KMEM_SIZE_VALID(x) ((x) % 251 == 1 && (x) != 1)
96
97
98 #define KMEM_ALIGN 8 /* min guaranteed alignment */
99 #define KMEM_ALIGN_SHIFT 3 /* log2(KMEM_ALIGN) */
100 #define KMEM_VOID_FRACTION 8 /* never waste more than 1/8 of slab */
101
102 #define KMEM_SLAB_IS_PARTIAL(sp) \
103 ((sp)->slab_refcnt > 0 && (sp)->slab_refcnt < (sp)->slab_chunks)
104 #define KMEM_SLAB_IS_ALL_USED(sp) \
105 ((sp)->slab_refcnt == (sp)->slab_chunks)
106
107 /*
108 * The bufctl (buffer control) structure keeps some minimal information
109 * about each buffer: its address, its slab, and its current linkage,
110 * which is either on the slab's freelist (if the buffer is free), or
111 * on the cache's buf-to-bufctl hash table (if the buffer is allocated).
112 * In the case of non-hashed, or "raw", caches (the common case), only
113 * the freelist linkage is necessary: the buffer address is at a fixed
114 * offset from the bufctl address, and the slab is at the end of the page.
115 *
116 * NOTE: bc_next must be the first field; raw buffers have linkage only.
117 */
118 typedef struct kmem_bufctl {
119 struct kmem_bufctl *bc_next; /* next bufctl struct */
120 void *bc_addr; /* address of buffer */
121 struct kmem_slab *bc_slab; /* controlling slab */
122 } kmem_bufctl_t;
123
124 /*
125 * The KMF_AUDIT version of the bufctl structure. The beginning of this
126 * structure must be identical to the normal bufctl structure so that
127 * pointers are interchangeable.
128 */
129 typedef struct kmem_bufctl_audit {
130 struct kmem_bufctl *bc_next; /* next bufctl struct */
131 void *bc_addr; /* address of buffer */
132 struct kmem_slab *bc_slab; /* controlling slab */
133 kmem_cache_t *bc_cache; /* controlling cache */
134 hrtime_t bc_timestamp; /* transaction time */
135 kthread_t *bc_thread; /* thread doing transaction */
136 struct kmem_bufctl *bc_lastlog; /* last log entry */
137 void *bc_contents; /* contents at last free */
138 int bc_depth; /* stack depth */
139 pc_t bc_stack[KMEM_STACK_DEPTH]; /* pc stack */
140 } kmem_bufctl_audit_t;
141
142 /*
143 * A kmem_buftag structure is appended to each buffer whenever any of the
144 * KMF_BUFTAG flags (KMF_DEADBEEF, KMF_REDZONE, KMF_VERIFY) are set.
145 */
146 typedef struct kmem_buftag {
147 uint64_t bt_redzone; /* 64-bit redzone pattern */
148 kmem_bufctl_t *bt_bufctl; /* bufctl */
149 intptr_t bt_bxstat; /* bufctl ^ (alloc/free) */
150 } kmem_buftag_t;
151
152 /*
153 * A variant of the kmem_buftag structure used for KMF_LITE caches.
154 * Previous callers are stored in reverse chronological order. (i.e. most
155 * recent first)
156 */
157 typedef struct kmem_buftag_lite {
158 kmem_buftag_t bt_buftag; /* a normal buftag */
159 pc_t bt_history[1]; /* zero or more callers */
160 } kmem_buftag_lite_t;
161
162 #define KMEM_BUFTAG_LITE_SIZE(f) \
163 (offsetof(kmem_buftag_lite_t, bt_history[f]))
164
165 #define KMEM_BUFTAG(cp, buf) \
166 ((kmem_buftag_t *)((char *)(buf) + (cp)->cache_buftag))
167
168 #define KMEM_BUFCTL(cp, buf) \
169 ((kmem_bufctl_t *)((char *)(buf) + (cp)->cache_bufctl))
170
171 #define KMEM_BUF(cp, bcp) \
172 ((void *)((char *)(bcp) - (cp)->cache_bufctl))
173
174 #define KMEM_SLAB(cp, buf) \
175 ((kmem_slab_t *)P2END((uintptr_t)(buf), (cp)->cache_slabsize) - 1)
176
177 /*
178 * Test for using alternate memory at dump time.
179 */
180 #define KMEM_DUMP(cp) ((cp)->cache_flags & KMF_DUMPDIVERT)
181 #define KMEM_DUMPCC(ccp) ((ccp)->cc_flags & KMF_DUMPDIVERT)
182
183 /*
184 * The "CPU" macro loads a cpu_t that refers to the cpu that the current
185 * thread is running on at the time the macro is executed. A context switch
186 * may occur immediately after loading this data structure, leaving this
187 * thread pointing at the cpu_t for the previous cpu. This is not a problem;
188 * we'd just end up checking the previous cpu's per-cpu cache, and then check
189 * the other layers of the kmem cache if need be.
190 *
191 * It's not even a problem if the old cpu gets DR'ed out during the context
192 * switch. The cpu-remove DR operation bzero()s the cpu_t, but doesn't free
193 * it. So the cpu_t's cpu_cache_offset would read as 0, causing us to use
194 * cpu 0's per-cpu cache.
195 *
196 * So, there is no need to disable kernel preemption while using the CPU macro
197 * below since if we have been context switched, there will not be any
198 * correctness problem, just a momentary use of a different per-cpu cache.
199 */
200
201 #define KMEM_CPU_CACHE(cp) \
202 ((kmem_cpu_cache_t *)((char *)(&cp->cache_cpu) + CPU->cpu_cache_offset))
203
204 #define KMEM_MAGAZINE_VALID(cp, mp) \
205 (((kmem_slab_t *)P2END((uintptr_t)(mp), PAGESIZE) - 1)->slab_cache == \
206 (cp)->cache_magtype->mt_cache)
207
208 #define KMEM_SLAB_OFFSET(sp, buf) \
209 ((size_t)((uintptr_t)(buf) - (uintptr_t)((sp)->slab_base)))
210
211 #define KMEM_SLAB_MEMBER(sp, buf) \
212 (KMEM_SLAB_OFFSET(sp, buf) < (sp)->slab_cache->cache_slabsize)
213
214 #define KMEM_BUFTAG_ALLOC 0xa110c8edUL
215 #define KMEM_BUFTAG_FREE 0xf4eef4eeUL
216
217 /* slab_later_count thresholds */
218 #define KMEM_DISBELIEF 3
219
220 /* slab_flags */
221 #define KMEM_SLAB_NOMOVE 0x1
222 #define KMEM_SLAB_MOVE_PENDING 0x2
223
224 typedef struct kmem_slab {
225 struct kmem_cache *slab_cache; /* controlling cache */
226 void *slab_base; /* base of allocated memory */
227 avl_node_t slab_link; /* slab linkage */
228 struct kmem_bufctl *slab_head; /* first free buffer */
229 long slab_refcnt; /* outstanding allocations */
230 long slab_chunks; /* chunks (bufs) in this slab */
231 uint32_t slab_stuck_offset; /* unmoved buffer offset */
232 uint16_t slab_later_count; /* cf KMEM_CBRC_LATER */
233 uint16_t slab_flags; /* bits to mark the slab */
234 } kmem_slab_t;
235
236 #define KMEM_HASH_INITIAL 64
237
238 #define KMEM_HASH(cp, buf) \
239 ((cp)->cache_hash_table + \
240 (((uintptr_t)(buf) >> (cp)->cache_hash_shift) & (cp)->cache_hash_mask))
241
242 typedef struct kmem_magazine {
243 void *mag_next;
244 void *mag_round[1]; /* one or more rounds */
245 } kmem_magazine_t;
246
247 /*
248 * The magazine types for fast per-cpu allocation
249 */
250 typedef struct kmem_magtype {
251 short mt_magsize; /* magazine size (number of rounds) */
252 int mt_align; /* magazine alignment */
253 size_t mt_minbuf; /* all smaller buffers qualify */
254 size_t mt_maxbuf; /* no larger buffers qualify */
255 kmem_cache_t *mt_cache; /* magazine cache */
256 } kmem_magtype_t;
257
258 #define KMEM_CPU_CACHE_SIZE 64 /* must be power of 2 */
259 #define KMEM_CPU_PAD (KMEM_CPU_CACHE_SIZE - sizeof (kmutex_t) - \
260 2 * sizeof (uint64_t) - 2 * sizeof (void *) - sizeof (int) - \
261 5 * sizeof (short))
262 #define KMEM_CACHE_SIZE(ncpus) \
263 ((size_t)(&((kmem_cache_t *)0)->cache_cpu[ncpus]))
264
265 /* Offset from kmem_cache->cache_cpu for per cpu caches */
266 #define KMEM_CPU_CACHE_OFFSET(cpuid) \
267 ((size_t)(&((kmem_cache_t *)0)->cache_cpu[cpuid]) - \
268 (size_t)(&((kmem_cache_t *)0)->cache_cpu))
269
270 typedef struct kmem_cpu_cache {
271 kmutex_t cc_lock; /* protects this cpu's local cache */
272 uint64_t cc_alloc; /* allocations from this cpu */
273 uint64_t cc_free; /* frees to this cpu */
274 kmem_magazine_t *cc_loaded; /* the currently loaded magazine */
275 kmem_magazine_t *cc_ploaded; /* the previously loaded magazine */
276 int cc_flags; /* CPU-local copy of cache_flags */
277 short cc_rounds; /* number of objects in loaded mag */
278 short cc_prounds; /* number of objects in previous mag */
279 short cc_magsize; /* number of rounds in a full mag */
280 short cc_dump_rounds; /* dump time copy of cc_rounds */
281 short cc_dump_prounds; /* dump time copy of cc_prounds */
282 char cc_pad[KMEM_CPU_PAD]; /* for nice alignment */
283 } kmem_cpu_cache_t;
284
285 /*
286 * The magazine lists used in the depot.
287 */
288 typedef struct kmem_maglist {
289 kmem_magazine_t *ml_list; /* magazine list */
290 long ml_total; /* number of magazines */
291 long ml_min; /* min since last update */
292 long ml_reaplimit; /* max reapable magazines */
293 uint64_t ml_alloc; /* allocations from this list */
294 } kmem_maglist_t;
295
296 typedef struct kmem_defrag {
297 /*
298 * Statistics
299 */
300 uint64_t kmd_callbacks; /* move callbacks */
301 uint64_t kmd_yes; /* KMEM_CBRC_YES responses */
302 uint64_t kmd_no; /* NO responses */
303 uint64_t kmd_later; /* LATER responses */
304 uint64_t kmd_dont_need; /* DONT_NEED responses */
305 uint64_t kmd_dont_know; /* DONT_KNOW responses */
306 uint64_t kmd_slabs_freed; /* slabs freed by moves */
307 uint64_t kmd_defrags; /* kmem_cache_defrag() */
308 uint64_t kmd_scans; /* kmem_cache_scan() */
309
310 /*
311 * Consolidator fields
312 */
313 avl_tree_t kmd_moves_pending; /* buffer moves pending */
314 list_t kmd_deadlist; /* deferred slab frees */
315 size_t kmd_deadcount; /* # of slabs in kmd_deadlist */
316 uint8_t kmd_reclaim_numer; /* slab usage threshold */
317 uint8_t kmd_pad1; /* compiler padding */
318 uint16_t kmd_consolidate; /* triggers consolidator */
319 uint32_t kmd_pad2; /* compiler padding */
320 size_t kmd_slabs_sought; /* reclaimable slabs sought */
321 size_t kmd_slabs_found; /* reclaimable slabs found */
322 size_t kmd_tries; /* nth scan interval counter */
323 /*
324 * Fields used to ASSERT that the client does not kmem_cache_free()
325 * objects passed to the move callback.
326 */
327 void *kmd_from_buf; /* object to move */
328 void *kmd_to_buf; /* move destination */
329 kthread_t *kmd_thread; /* thread calling move */
330 } kmem_defrag_t;
331
332 typedef struct kmem_dump {
333 void *kd_freelist; /* heap during crash dump */
334 uint_t kd_alloc_fails; /* # of allocation failures */
335 uint_t kd_unsafe; /* cache was used, but unsafe */
336 } kmem_dump_t;
337
338 #define KMEM_CACHE_NAMELEN 31
339
340 struct kmem_cache {
341 /*
342 * Statistics
343 */
344 uint64_t cache_slab_create; /* slab creates */
345 uint64_t cache_slab_destroy; /* slab destroys */
346 uint64_t cache_slab_alloc; /* slab layer allocations */
347 uint64_t cache_slab_free; /* slab layer frees */
348 uint64_t cache_alloc_fail; /* total failed allocations */
349 uint64_t cache_buftotal; /* total buffers */
350 uint64_t cache_bufmax; /* max buffers ever */
351 uint64_t cache_bufslab; /* buffers free in slab layer */
352 uint64_t cache_reap; /* cache reaps */
353 uint64_t cache_rescale; /* hash table rescales */
354 uint64_t cache_lookup_depth; /* hash lookup depth */
355 uint64_t cache_depot_contention; /* mutex contention count */
356 uint64_t cache_depot_contention_prev; /* previous snapshot */
357
358 /*
359 * Cache properties
360 */
361 char cache_name[KMEM_CACHE_NAMELEN + 1];
362 size_t cache_bufsize; /* object size */
363 size_t cache_align; /* object alignment */
364 int (*cache_constructor)(void *, void *, int);
365 void (*cache_destructor)(void *, void *);
366 void (*cache_reclaim)(void *);
367 kmem_cbrc_t (*cache_move)(void *, void *, size_t, void *);
368 void *cache_private; /* opaque arg to callbacks */
369 vmem_t *cache_arena; /* vmem source for slabs */
370 int cache_cflags; /* cache creation flags */
371 int cache_flags; /* various cache state info */
372 uint32_t cache_mtbf; /* induced alloc failure rate */
373 uint32_t cache_pad1; /* compiler padding */
374 kstat_t *cache_kstat; /* exported statistics */
375 list_node_t cache_link; /* cache linkage */
376
377 /*
378 * Slab layer
379 */
380 kmutex_t cache_lock; /* protects slab layer */
381 size_t cache_chunksize; /* buf + alignment [+ debug] */
382 size_t cache_slabsize; /* size of a slab */
383 size_t cache_maxchunks; /* max buffers per slab */
384 size_t cache_bufctl; /* buf-to-bufctl distance */
385 size_t cache_buftag; /* buf-to-buftag distance */
386 size_t cache_verify; /* bytes to verify */
387 size_t cache_contents; /* bytes of saved content */
388 size_t cache_color; /* next slab color */
389 size_t cache_mincolor; /* maximum slab color */
390 size_t cache_maxcolor; /* maximum slab color */
391 size_t cache_hash_shift; /* get to interesting bits */
392 size_t cache_hash_mask; /* hash table mask */
393 list_t cache_complete_slabs; /* completely allocated slabs */
394 size_t cache_complete_slab_count;
395 avl_tree_t cache_partial_slabs; /* partial slab freelist */
396 size_t cache_partial_binshift; /* for AVL sort bins */
397 kmem_cache_t *cache_bufctl_cache; /* source of bufctls */
398 kmem_bufctl_t **cache_hash_table; /* hash table base */
399 kmem_defrag_t *cache_defrag; /* slab consolidator fields */
400
401 /*
402 * Depot layer
403 */
404 kmutex_t cache_depot_lock; /* protects depot */
405 kmem_magtype_t *cache_magtype; /* magazine type */
406 kmem_maglist_t cache_full; /* full magazines */
407 kmem_maglist_t cache_empty; /* empty magazines */
408 kmem_dump_t cache_dump; /* used during crash dump */
409
410 /*
411 * Per-CPU layer
412 */
413 kmem_cpu_cache_t cache_cpu[1]; /* max_ncpus actual elements */
414 };
415
416 typedef struct kmem_cpu_log_header {
417 kmutex_t clh_lock;
418 char *clh_current;
419 size_t clh_avail;
420 int clh_chunk;
421 int clh_hits;
422 char clh_pad[64 - sizeof (kmutex_t) - sizeof (char *) -
423 sizeof (size_t) - 2 * sizeof (int)];
424 } kmem_cpu_log_header_t;
425
426 typedef struct kmem_log_header {
427 kmutex_t lh_lock;
428 char *lh_base;
429 int *lh_free;
430 size_t lh_chunksize;
431 int lh_nchunks;
432 int lh_head;
433 int lh_tail;
434 int lh_hits;
435 kmem_cpu_log_header_t lh_cpu[1]; /* ncpus actually allocated */
436 } kmem_log_header_t;
437
438 /* kmem_move kmm_flags */
439 #define KMM_DESPERATE 0x1
440 #define KMM_NOTIFY 0x2
441 #define KMM_DEBUG 0x4
442
443 typedef struct kmem_move {
444 kmem_slab_t *kmm_from_slab;
445 void *kmm_from_buf;
446 void *kmm_to_buf;
447 avl_node_t kmm_entry;
448 int kmm_flags;
449 } kmem_move_t;
450
451 /*
452 * In order to consolidate partial slabs, it must be possible for the cache to
453 * have partial slabs.
454 */
455 #define KMEM_IS_MOVABLE(cp) \
456 (((cp)->cache_chunksize * 2) <= (cp)->cache_slabsize)
457
458 #ifdef __cplusplus
459 }
460 #endif
461
462 #endif /* _SYS_KMEM_IMPL_H */