Print this page
9525 kmem_dump_size is a corrupting influence
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Dan McDonald <danmcd@joyent.com>
| Split |
Close |
| Expand all |
| Collapse all |
--- old/usr/src/uts/common/sys/kmem_impl.h
+++ new/usr/src/uts/common/sys/kmem_impl.h
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
|
↓ open down ↓ |
13 lines elided |
↑ open up ↑ |
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21
22 22 /*
23 23 * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
24 + * Copyright 2018 Joyent, Inc.
24 25 */
25 26
26 27 #ifndef _SYS_KMEM_IMPL_H
27 28 #define _SYS_KMEM_IMPL_H
28 29
29 30 #include <sys/kmem.h>
30 31 #include <sys/vmem.h>
31 32 #include <sys/thread.h>
32 33 #include <sys/t_lock.h>
33 34 #include <sys/time.h>
34 35 #include <sys/kstat.h>
35 36 #include <sys/cpuvar.h>
36 37 #include <sys/systm.h>
37 38 #include <vm/page.h>
38 39 #include <sys/avl.h>
39 40 #include <sys/list.h>
40 41
41 42 #ifdef __cplusplus
42 43 extern "C" {
43 44 #endif
44 45
45 46 /*
46 47 * kernel memory allocator: implementation-private data structures
47 48 *
48 49 * Lock order:
49 50 * 1. cache_lock
50 51 * 2. cc_lock in order by CPU ID
51 52 * 3. cache_depot_lock
52 53 *
53 54 * Do not call kmem_cache_alloc() or taskq_dispatch() while holding any of the
54 55 * above locks.
55 56 */
56 57
57 58 #define KMF_AUDIT 0x00000001 /* transaction auditing */
58 59 #define KMF_DEADBEEF 0x00000002 /* deadbeef checking */
59 60 #define KMF_REDZONE 0x00000004 /* redzone checking */
60 61 #define KMF_CONTENTS 0x00000008 /* freed-buffer content logging */
61 62 #define KMF_STICKY 0x00000010 /* if set, override /etc/system */
62 63 #define KMF_NOMAGAZINE 0x00000020 /* disable per-cpu magazines */
63 64 #define KMF_FIREWALL 0x00000040 /* put all bufs before unmapped pages */
64 65 #define KMF_LITE 0x00000100 /* lightweight debugging */
65 66
66 67 #define KMF_HASH 0x00000200 /* cache has hash table */
67 68 #define KMF_RANDOMIZE 0x00000400 /* randomize other kmem_flags */
68 69
69 70 #define KMF_DUMPDIVERT 0x00001000 /* use alternate memory at dump time */
70 71 #define KMF_DUMPUNSAFE 0x00002000 /* flag caches used at dump time */
71 72 #define KMF_PREFILL 0x00004000 /* Prefill the slab when created. */
72 73
73 74 #define KMF_BUFTAG (KMF_DEADBEEF | KMF_REDZONE)
74 75 #define KMF_TOUCH (KMF_BUFTAG | KMF_LITE | KMF_CONTENTS)
75 76 #define KMF_RANDOM (KMF_TOUCH | KMF_AUDIT | KMF_NOMAGAZINE)
76 77 #define KMF_DEBUG (KMF_RANDOM | KMF_FIREWALL)
77 78
78 79 #define KMEM_STACK_DEPTH 15
79 80
80 81 #define KMEM_FREE_PATTERN 0xdeadbeefdeadbeefULL
81 82 #define KMEM_UNINITIALIZED_PATTERN 0xbaddcafebaddcafeULL
82 83 #define KMEM_REDZONE_PATTERN 0xfeedfacefeedfaceULL
83 84 #define KMEM_REDZONE_BYTE 0xbb
84 85
85 86 /*
86 87 * Redzone size encodings for kmem_alloc() / kmem_free(). We encode the
87 88 * allocation size, rather than storing it directly, so that kmem_free()
88 89 * can distinguish frees of the wrong size from redzone violations.
89 90 *
90 91 * A size of zero is never valid.
91 92 */
92 93 #define KMEM_SIZE_ENCODE(x) (251 * (x) + 1)
93 94 #define KMEM_SIZE_DECODE(x) ((x) / 251)
94 95 #define KMEM_SIZE_VALID(x) ((x) % 251 == 1 && (x) != 1)
95 96
96 97
97 98 #define KMEM_ALIGN 8 /* min guaranteed alignment */
98 99 #define KMEM_ALIGN_SHIFT 3 /* log2(KMEM_ALIGN) */
99 100 #define KMEM_VOID_FRACTION 8 /* never waste more than 1/8 of slab */
100 101
101 102 #define KMEM_SLAB_IS_PARTIAL(sp) \
102 103 ((sp)->slab_refcnt > 0 && (sp)->slab_refcnt < (sp)->slab_chunks)
103 104 #define KMEM_SLAB_IS_ALL_USED(sp) \
104 105 ((sp)->slab_refcnt == (sp)->slab_chunks)
105 106
106 107 /*
107 108 * The bufctl (buffer control) structure keeps some minimal information
108 109 * about each buffer: its address, its slab, and its current linkage,
109 110 * which is either on the slab's freelist (if the buffer is free), or
110 111 * on the cache's buf-to-bufctl hash table (if the buffer is allocated).
111 112 * In the case of non-hashed, or "raw", caches (the common case), only
112 113 * the freelist linkage is necessary: the buffer address is at a fixed
113 114 * offset from the bufctl address, and the slab is at the end of the page.
114 115 *
115 116 * NOTE: bc_next must be the first field; raw buffers have linkage only.
116 117 */
117 118 typedef struct kmem_bufctl {
118 119 struct kmem_bufctl *bc_next; /* next bufctl struct */
119 120 void *bc_addr; /* address of buffer */
120 121 struct kmem_slab *bc_slab; /* controlling slab */
121 122 } kmem_bufctl_t;
122 123
123 124 /*
124 125 * The KMF_AUDIT version of the bufctl structure. The beginning of this
125 126 * structure must be identical to the normal bufctl structure so that
126 127 * pointers are interchangeable.
127 128 */
128 129 typedef struct kmem_bufctl_audit {
129 130 struct kmem_bufctl *bc_next; /* next bufctl struct */
130 131 void *bc_addr; /* address of buffer */
131 132 struct kmem_slab *bc_slab; /* controlling slab */
132 133 kmem_cache_t *bc_cache; /* controlling cache */
133 134 hrtime_t bc_timestamp; /* transaction time */
134 135 kthread_t *bc_thread; /* thread doing transaction */
135 136 struct kmem_bufctl *bc_lastlog; /* last log entry */
136 137 void *bc_contents; /* contents at last free */
137 138 int bc_depth; /* stack depth */
138 139 pc_t bc_stack[KMEM_STACK_DEPTH]; /* pc stack */
139 140 } kmem_bufctl_audit_t;
140 141
141 142 /*
142 143 * A kmem_buftag structure is appended to each buffer whenever any of the
143 144 * KMF_BUFTAG flags (KMF_DEADBEEF, KMF_REDZONE, KMF_VERIFY) are set.
144 145 */
145 146 typedef struct kmem_buftag {
146 147 uint64_t bt_redzone; /* 64-bit redzone pattern */
147 148 kmem_bufctl_t *bt_bufctl; /* bufctl */
148 149 intptr_t bt_bxstat; /* bufctl ^ (alloc/free) */
149 150 } kmem_buftag_t;
150 151
151 152 /*
152 153 * A variant of the kmem_buftag structure used for KMF_LITE caches.
153 154 * Previous callers are stored in reverse chronological order. (i.e. most
154 155 * recent first)
155 156 */
156 157 typedef struct kmem_buftag_lite {
157 158 kmem_buftag_t bt_buftag; /* a normal buftag */
158 159 pc_t bt_history[1]; /* zero or more callers */
159 160 } kmem_buftag_lite_t;
160 161
161 162 #define KMEM_BUFTAG_LITE_SIZE(f) \
162 163 (offsetof(kmem_buftag_lite_t, bt_history[f]))
163 164
164 165 #define KMEM_BUFTAG(cp, buf) \
165 166 ((kmem_buftag_t *)((char *)(buf) + (cp)->cache_buftag))
166 167
167 168 #define KMEM_BUFCTL(cp, buf) \
168 169 ((kmem_bufctl_t *)((char *)(buf) + (cp)->cache_bufctl))
169 170
170 171 #define KMEM_BUF(cp, bcp) \
171 172 ((void *)((char *)(bcp) - (cp)->cache_bufctl))
172 173
173 174 #define KMEM_SLAB(cp, buf) \
174 175 ((kmem_slab_t *)P2END((uintptr_t)(buf), (cp)->cache_slabsize) - 1)
175 176
176 177 /*
177 178 * Test for using alternate memory at dump time.
178 179 */
179 180 #define KMEM_DUMP(cp) ((cp)->cache_flags & KMF_DUMPDIVERT)
180 181 #define KMEM_DUMPCC(ccp) ((ccp)->cc_flags & KMF_DUMPDIVERT)
181 182
182 183 /*
183 184 * The "CPU" macro loads a cpu_t that refers to the cpu that the current
184 185 * thread is running on at the time the macro is executed. A context switch
185 186 * may occur immediately after loading this data structure, leaving this
186 187 * thread pointing at the cpu_t for the previous cpu. This is not a problem;
187 188 * we'd just end up checking the previous cpu's per-cpu cache, and then check
188 189 * the other layers of the kmem cache if need be.
189 190 *
190 191 * It's not even a problem if the old cpu gets DR'ed out during the context
191 192 * switch. The cpu-remove DR operation bzero()s the cpu_t, but doesn't free
192 193 * it. So the cpu_t's cpu_cache_offset would read as 0, causing us to use
193 194 * cpu 0's per-cpu cache.
194 195 *
195 196 * So, there is no need to disable kernel preemption while using the CPU macro
196 197 * below since if we have been context switched, there will not be any
197 198 * correctness problem, just a momentary use of a different per-cpu cache.
198 199 */
199 200
200 201 #define KMEM_CPU_CACHE(cp) \
201 202 ((kmem_cpu_cache_t *)((char *)(&cp->cache_cpu) + CPU->cpu_cache_offset))
202 203
203 204 #define KMEM_MAGAZINE_VALID(cp, mp) \
204 205 (((kmem_slab_t *)P2END((uintptr_t)(mp), PAGESIZE) - 1)->slab_cache == \
205 206 (cp)->cache_magtype->mt_cache)
206 207
207 208 #define KMEM_SLAB_OFFSET(sp, buf) \
208 209 ((size_t)((uintptr_t)(buf) - (uintptr_t)((sp)->slab_base)))
209 210
210 211 #define KMEM_SLAB_MEMBER(sp, buf) \
211 212 (KMEM_SLAB_OFFSET(sp, buf) < (sp)->slab_cache->cache_slabsize)
212 213
213 214 #define KMEM_BUFTAG_ALLOC 0xa110c8edUL
214 215 #define KMEM_BUFTAG_FREE 0xf4eef4eeUL
215 216
216 217 /* slab_later_count thresholds */
217 218 #define KMEM_DISBELIEF 3
218 219
219 220 /* slab_flags */
220 221 #define KMEM_SLAB_NOMOVE 0x1
221 222 #define KMEM_SLAB_MOVE_PENDING 0x2
222 223
223 224 typedef struct kmem_slab {
224 225 struct kmem_cache *slab_cache; /* controlling cache */
225 226 void *slab_base; /* base of allocated memory */
226 227 avl_node_t slab_link; /* slab linkage */
227 228 struct kmem_bufctl *slab_head; /* first free buffer */
228 229 long slab_refcnt; /* outstanding allocations */
229 230 long slab_chunks; /* chunks (bufs) in this slab */
230 231 uint32_t slab_stuck_offset; /* unmoved buffer offset */
231 232 uint16_t slab_later_count; /* cf KMEM_CBRC_LATER */
232 233 uint16_t slab_flags; /* bits to mark the slab */
233 234 } kmem_slab_t;
234 235
235 236 #define KMEM_HASH_INITIAL 64
236 237
237 238 #define KMEM_HASH(cp, buf) \
238 239 ((cp)->cache_hash_table + \
239 240 (((uintptr_t)(buf) >> (cp)->cache_hash_shift) & (cp)->cache_hash_mask))
240 241
241 242 typedef struct kmem_magazine {
242 243 void *mag_next;
243 244 void *mag_round[1]; /* one or more rounds */
244 245 } kmem_magazine_t;
245 246
246 247 /*
247 248 * The magazine types for fast per-cpu allocation
248 249 */
249 250 typedef struct kmem_magtype {
250 251 short mt_magsize; /* magazine size (number of rounds) */
251 252 int mt_align; /* magazine alignment */
252 253 size_t mt_minbuf; /* all smaller buffers qualify */
253 254 size_t mt_maxbuf; /* no larger buffers qualify */
254 255 kmem_cache_t *mt_cache; /* magazine cache */
255 256 } kmem_magtype_t;
256 257
257 258 #define KMEM_CPU_CACHE_SIZE 64 /* must be power of 2 */
258 259 #define KMEM_CPU_PAD (KMEM_CPU_CACHE_SIZE - sizeof (kmutex_t) - \
259 260 2 * sizeof (uint64_t) - 2 * sizeof (void *) - sizeof (int) - \
260 261 5 * sizeof (short))
261 262 #define KMEM_CACHE_SIZE(ncpus) \
262 263 ((size_t)(&((kmem_cache_t *)0)->cache_cpu[ncpus]))
263 264
264 265 /* Offset from kmem_cache->cache_cpu for per cpu caches */
265 266 #define KMEM_CPU_CACHE_OFFSET(cpuid) \
266 267 ((size_t)(&((kmem_cache_t *)0)->cache_cpu[cpuid]) - \
267 268 (size_t)(&((kmem_cache_t *)0)->cache_cpu))
268 269
269 270 typedef struct kmem_cpu_cache {
270 271 kmutex_t cc_lock; /* protects this cpu's local cache */
271 272 uint64_t cc_alloc; /* allocations from this cpu */
272 273 uint64_t cc_free; /* frees to this cpu */
273 274 kmem_magazine_t *cc_loaded; /* the currently loaded magazine */
274 275 kmem_magazine_t *cc_ploaded; /* the previously loaded magazine */
275 276 int cc_flags; /* CPU-local copy of cache_flags */
276 277 short cc_rounds; /* number of objects in loaded mag */
277 278 short cc_prounds; /* number of objects in previous mag */
278 279 short cc_magsize; /* number of rounds in a full mag */
279 280 short cc_dump_rounds; /* dump time copy of cc_rounds */
280 281 short cc_dump_prounds; /* dump time copy of cc_prounds */
281 282 char cc_pad[KMEM_CPU_PAD]; /* for nice alignment */
282 283 } kmem_cpu_cache_t;
283 284
284 285 /*
285 286 * The magazine lists used in the depot.
286 287 */
287 288 typedef struct kmem_maglist {
288 289 kmem_magazine_t *ml_list; /* magazine list */
289 290 long ml_total; /* number of magazines */
290 291 long ml_min; /* min since last update */
291 292 long ml_reaplimit; /* max reapable magazines */
292 293 uint64_t ml_alloc; /* allocations from this list */
293 294 } kmem_maglist_t;
294 295
295 296 typedef struct kmem_defrag {
296 297 /*
297 298 * Statistics
298 299 */
299 300 uint64_t kmd_callbacks; /* move callbacks */
300 301 uint64_t kmd_yes; /* KMEM_CBRC_YES responses */
301 302 uint64_t kmd_no; /* NO responses */
302 303 uint64_t kmd_later; /* LATER responses */
303 304 uint64_t kmd_dont_need; /* DONT_NEED responses */
304 305 uint64_t kmd_dont_know; /* DONT_KNOW responses */
305 306 uint64_t kmd_slabs_freed; /* slabs freed by moves */
306 307 uint64_t kmd_defrags; /* kmem_cache_defrag() */
307 308 uint64_t kmd_scans; /* kmem_cache_scan() */
308 309
309 310 /*
310 311 * Consolidator fields
311 312 */
312 313 avl_tree_t kmd_moves_pending; /* buffer moves pending */
313 314 list_t kmd_deadlist; /* deferred slab frees */
314 315 size_t kmd_deadcount; /* # of slabs in kmd_deadlist */
315 316 uint8_t kmd_reclaim_numer; /* slab usage threshold */
316 317 uint8_t kmd_pad1; /* compiler padding */
317 318 uint16_t kmd_consolidate; /* triggers consolidator */
318 319 uint32_t kmd_pad2; /* compiler padding */
319 320 size_t kmd_slabs_sought; /* reclaimable slabs sought */
320 321 size_t kmd_slabs_found; /* reclaimable slabs found */
|
↓ open down ↓ |
287 lines elided |
↑ open up ↑ |
321 322 size_t kmd_tries; /* nth scan interval counter */
322 323 /*
323 324 * Fields used to ASSERT that the client does not kmem_cache_free()
324 325 * objects passed to the move callback.
325 326 */
326 327 void *kmd_from_buf; /* object to move */
327 328 void *kmd_to_buf; /* move destination */
328 329 kthread_t *kmd_thread; /* thread calling move */
329 330 } kmem_defrag_t;
330 331
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 +
331 338 #define KMEM_CACHE_NAMELEN 31
332 339
333 340 struct kmem_cache {
334 341 /*
335 342 * Statistics
336 343 */
337 344 uint64_t cache_slab_create; /* slab creates */
338 345 uint64_t cache_slab_destroy; /* slab destroys */
339 346 uint64_t cache_slab_alloc; /* slab layer allocations */
340 347 uint64_t cache_slab_free; /* slab layer frees */
341 348 uint64_t cache_alloc_fail; /* total failed allocations */
342 349 uint64_t cache_buftotal; /* total buffers */
343 350 uint64_t cache_bufmax; /* max buffers ever */
344 351 uint64_t cache_bufslab; /* buffers free in slab layer */
345 352 uint64_t cache_reap; /* cache reaps */
346 353 uint64_t cache_rescale; /* hash table rescales */
347 354 uint64_t cache_lookup_depth; /* hash lookup depth */
348 355 uint64_t cache_depot_contention; /* mutex contention count */
349 356 uint64_t cache_depot_contention_prev; /* previous snapshot */
350 357
351 358 /*
352 359 * Cache properties
353 360 */
354 361 char cache_name[KMEM_CACHE_NAMELEN + 1];
355 362 size_t cache_bufsize; /* object size */
356 363 size_t cache_align; /* object alignment */
357 364 int (*cache_constructor)(void *, void *, int);
358 365 void (*cache_destructor)(void *, void *);
359 366 void (*cache_reclaim)(void *);
360 367 kmem_cbrc_t (*cache_move)(void *, void *, size_t, void *);
361 368 void *cache_private; /* opaque arg to callbacks */
362 369 vmem_t *cache_arena; /* vmem source for slabs */
363 370 int cache_cflags; /* cache creation flags */
364 371 int cache_flags; /* various cache state info */
365 372 uint32_t cache_mtbf; /* induced alloc failure rate */
366 373 uint32_t cache_pad1; /* compiler padding */
367 374 kstat_t *cache_kstat; /* exported statistics */
368 375 list_node_t cache_link; /* cache linkage */
369 376
370 377 /*
371 378 * Slab layer
372 379 */
373 380 kmutex_t cache_lock; /* protects slab layer */
374 381 size_t cache_chunksize; /* buf + alignment [+ debug] */
375 382 size_t cache_slabsize; /* size of a slab */
376 383 size_t cache_maxchunks; /* max buffers per slab */
377 384 size_t cache_bufctl; /* buf-to-bufctl distance */
378 385 size_t cache_buftag; /* buf-to-buftag distance */
379 386 size_t cache_verify; /* bytes to verify */
380 387 size_t cache_contents; /* bytes of saved content */
381 388 size_t cache_color; /* next slab color */
382 389 size_t cache_mincolor; /* maximum slab color */
383 390 size_t cache_maxcolor; /* maximum slab color */
384 391 size_t cache_hash_shift; /* get to interesting bits */
385 392 size_t cache_hash_mask; /* hash table mask */
386 393 list_t cache_complete_slabs; /* completely allocated slabs */
387 394 size_t cache_complete_slab_count;
388 395 avl_tree_t cache_partial_slabs; /* partial slab freelist */
389 396 size_t cache_partial_binshift; /* for AVL sort bins */
390 397 kmem_cache_t *cache_bufctl_cache; /* source of bufctls */
|
↓ open down ↓ |
50 lines elided |
↑ open up ↑ |
391 398 kmem_bufctl_t **cache_hash_table; /* hash table base */
392 399 kmem_defrag_t *cache_defrag; /* slab consolidator fields */
393 400
394 401 /*
395 402 * Depot layer
396 403 */
397 404 kmutex_t cache_depot_lock; /* protects depot */
398 405 kmem_magtype_t *cache_magtype; /* magazine type */
399 406 kmem_maglist_t cache_full; /* full magazines */
400 407 kmem_maglist_t cache_empty; /* empty magazines */
401 - void *cache_dumpfreelist; /* heap during crash dump */
402 - void *cache_dumplog; /* log entry during dump */
408 + kmem_dump_t cache_dump; /* used during crash dump */
403 409
404 410 /*
405 411 * Per-CPU layer
406 412 */
407 413 kmem_cpu_cache_t cache_cpu[1]; /* max_ncpus actual elements */
408 414 };
409 415
410 416 typedef struct kmem_cpu_log_header {
411 417 kmutex_t clh_lock;
412 418 char *clh_current;
413 419 size_t clh_avail;
414 420 int clh_chunk;
415 421 int clh_hits;
416 422 char clh_pad[64 - sizeof (kmutex_t) - sizeof (char *) -
417 423 sizeof (size_t) - 2 * sizeof (int)];
418 424 } kmem_cpu_log_header_t;
419 425
420 426 typedef struct kmem_log_header {
421 427 kmutex_t lh_lock;
422 428 char *lh_base;
423 429 int *lh_free;
424 430 size_t lh_chunksize;
425 431 int lh_nchunks;
426 432 int lh_head;
427 433 int lh_tail;
428 434 int lh_hits;
429 435 kmem_cpu_log_header_t lh_cpu[1]; /* ncpus actually allocated */
430 436 } kmem_log_header_t;
431 437
432 438 /* kmem_move kmm_flags */
433 439 #define KMM_DESPERATE 0x1
434 440 #define KMM_NOTIFY 0x2
435 441 #define KMM_DEBUG 0x4
436 442
437 443 typedef struct kmem_move {
438 444 kmem_slab_t *kmm_from_slab;
439 445 void *kmm_from_buf;
440 446 void *kmm_to_buf;
441 447 avl_node_t kmm_entry;
442 448 int kmm_flags;
443 449 } kmem_move_t;
444 450
445 451 /*
446 452 * In order to consolidate partial slabs, it must be possible for the cache to
447 453 * have partial slabs.
448 454 */
449 455 #define KMEM_IS_MOVABLE(cp) \
450 456 (((cp)->cache_chunksize * 2) <= (cp)->cache_slabsize)
451 457
452 458 #ifdef __cplusplus
453 459 }
454 460 #endif
455 461
456 462 #endif /* _SYS_KMEM_IMPL_H */
|
↓ open down ↓ |
44 lines elided |
↑ open up ↑ |
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX