xref: /freebsd/contrib/jemalloc/src/arena.c (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
1 #define	JEMALLOC_ARENA_C_
2 #include "jemalloc/internal/jemalloc_internal.h"
3 
4 /******************************************************************************/
5 /* Data. */
6 
7 ssize_t		opt_lg_dirty_mult = LG_DIRTY_MULT_DEFAULT;
8 static ssize_t	lg_dirty_mult_default;
9 arena_bin_info_t	arena_bin_info[NBINS];
10 
11 size_t		map_bias;
12 size_t		map_misc_offset;
13 size_t		arena_maxrun; /* Max run size for arenas. */
14 size_t		large_maxclass; /* Max large size class. */
15 static size_t	small_maxrun; /* Max run size used for small size classes. */
16 static bool	*small_run_tab; /* Valid small run page multiples. */
17 unsigned	nlclasses; /* Number of large size classes. */
18 unsigned	nhclasses; /* Number of huge size classes. */
19 
20 /******************************************************************************/
21 /*
22  * Function prototypes for static functions that are referenced prior to
23  * definition.
24  */
25 
26 static void	arena_purge(arena_t *arena, bool all);
27 static void	arena_run_dalloc(arena_t *arena, arena_run_t *run, bool dirty,
28     bool cleaned, bool decommitted);
29 static void	arena_dalloc_bin_run(arena_t *arena, arena_chunk_t *chunk,
30     arena_run_t *run, arena_bin_t *bin);
31 static void	arena_bin_lower_run(arena_t *arena, arena_chunk_t *chunk,
32     arena_run_t *run, arena_bin_t *bin);
33 
34 /******************************************************************************/
35 
36 #define	CHUNK_MAP_KEY		((uintptr_t)0x1U)
37 
38 JEMALLOC_INLINE_C arena_chunk_map_misc_t *
39 arena_miscelm_key_create(size_t size)
40 {
41 
42 	return ((arena_chunk_map_misc_t *)(arena_mapbits_size_encode(size) |
43 	    CHUNK_MAP_KEY));
44 }
45 
46 JEMALLOC_INLINE_C bool
47 arena_miscelm_is_key(const arena_chunk_map_misc_t *miscelm)
48 {
49 
50 	return (((uintptr_t)miscelm & CHUNK_MAP_KEY) != 0);
51 }
52 
53 #undef CHUNK_MAP_KEY
54 
55 JEMALLOC_INLINE_C size_t
56 arena_miscelm_key_size_get(const arena_chunk_map_misc_t *miscelm)
57 {
58 
59 	assert(arena_miscelm_is_key(miscelm));
60 
61 	return (arena_mapbits_size_decode((uintptr_t)miscelm));
62 }
63 
64 JEMALLOC_INLINE_C size_t
65 arena_miscelm_size_get(arena_chunk_map_misc_t *miscelm)
66 {
67 	arena_chunk_t *chunk;
68 	size_t pageind, mapbits;
69 
70 	assert(!arena_miscelm_is_key(miscelm));
71 
72 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(miscelm);
73 	pageind = arena_miscelm_to_pageind(miscelm);
74 	mapbits = arena_mapbits_get(chunk, pageind);
75 	return (arena_mapbits_size_decode(mapbits));
76 }
77 
78 JEMALLOC_INLINE_C int
79 arena_run_comp(arena_chunk_map_misc_t *a, arena_chunk_map_misc_t *b)
80 {
81 	uintptr_t a_miscelm = (uintptr_t)a;
82 	uintptr_t b_miscelm = (uintptr_t)b;
83 
84 	assert(a != NULL);
85 	assert(b != NULL);
86 
87 	return ((a_miscelm > b_miscelm) - (a_miscelm < b_miscelm));
88 }
89 
90 /* Generate red-black tree functions. */
91 rb_gen(static UNUSED, arena_run_tree_, arena_run_tree_t, arena_chunk_map_misc_t,
92     rb_link, arena_run_comp)
93 
94 static size_t
95 run_quantize(size_t size)
96 {
97 	size_t qsize;
98 
99 	assert(size != 0);
100 	assert(size == PAGE_CEILING(size));
101 
102 	/* Don't change sizes that are valid small run sizes. */
103 	if (size <= small_maxrun && small_run_tab[size >> LG_PAGE])
104 		return (size);
105 
106 	/*
107 	 * Round down to the nearest run size that can actually be requested
108 	 * during normal large allocation.  Add large_pad so that cache index
109 	 * randomization can offset the allocation from the page boundary.
110 	 */
111 	qsize = index2size(size2index(size - large_pad + 1) - 1) + large_pad;
112 	if (qsize <= SMALL_MAXCLASS + large_pad)
113 		return (run_quantize(size - large_pad));
114 	assert(qsize <= size);
115 	return (qsize);
116 }
117 
118 static size_t
119 run_quantize_next(size_t size)
120 {
121 	size_t large_run_size_next;
122 
123 	assert(size != 0);
124 	assert(size == PAGE_CEILING(size));
125 
126 	/*
127 	 * Return the next quantized size greater than the input size.
128 	 * Quantized sizes comprise the union of run sizes that back small
129 	 * region runs, and run sizes that back large regions with no explicit
130 	 * alignment constraints.
131 	 */
132 
133 	if (size > SMALL_MAXCLASS) {
134 		large_run_size_next = PAGE_CEILING(index2size(size2index(size -
135 		    large_pad) + 1) + large_pad);
136 	} else
137 		large_run_size_next = SIZE_T_MAX;
138 	if (size >= small_maxrun)
139 		return (large_run_size_next);
140 
141 	while (true) {
142 		size += PAGE;
143 		assert(size <= small_maxrun);
144 		if (small_run_tab[size >> LG_PAGE]) {
145 			if (large_run_size_next < size)
146 				return (large_run_size_next);
147 			return (size);
148 		}
149 	}
150 }
151 
152 static size_t
153 run_quantize_first(size_t size)
154 {
155 	size_t qsize = run_quantize(size);
156 
157 	if (qsize < size) {
158 		/*
159 		 * Skip a quantization that may have an adequately large run,
160 		 * because under-sized runs may be mixed in.  This only happens
161 		 * when an unusual size is requested, i.e. for aligned
162 		 * allocation, and is just one of several places where linear
163 		 * search would potentially find sufficiently aligned available
164 		 * memory somewhere lower.
165 		 */
166 		qsize = run_quantize_next(size);
167 	}
168 	return (qsize);
169 }
170 
171 JEMALLOC_INLINE_C int
172 arena_avail_comp(arena_chunk_map_misc_t *a, arena_chunk_map_misc_t *b)
173 {
174 	int ret;
175 	uintptr_t a_miscelm = (uintptr_t)a;
176 	size_t a_qsize = run_quantize(arena_miscelm_is_key(a) ?
177 	    arena_miscelm_key_size_get(a) : arena_miscelm_size_get(a));
178 	size_t b_qsize = run_quantize(arena_miscelm_size_get(b));
179 
180 	/*
181 	 * Compare based on quantized size rather than size, in order to sort
182 	 * equally useful runs only by address.
183 	 */
184 	ret = (a_qsize > b_qsize) - (a_qsize < b_qsize);
185 	if (ret == 0) {
186 		if (!arena_miscelm_is_key(a)) {
187 			uintptr_t b_miscelm = (uintptr_t)b;
188 
189 			ret = (a_miscelm > b_miscelm) - (a_miscelm < b_miscelm);
190 		} else {
191 			/*
192 			 * Treat keys as if they are lower than anything else.
193 			 */
194 			ret = -1;
195 		}
196 	}
197 
198 	return (ret);
199 }
200 
201 /* Generate red-black tree functions. */
202 rb_gen(static UNUSED, arena_avail_tree_, arena_avail_tree_t,
203     arena_chunk_map_misc_t, rb_link, arena_avail_comp)
204 
205 static void
206 arena_avail_insert(arena_t *arena, arena_chunk_t *chunk, size_t pageind,
207     size_t npages)
208 {
209 
210 	assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >>
211 	    LG_PAGE));
212 	arena_avail_tree_insert(&arena->runs_avail, arena_miscelm_get(chunk,
213 	    pageind));
214 }
215 
216 static void
217 arena_avail_remove(arena_t *arena, arena_chunk_t *chunk, size_t pageind,
218     size_t npages)
219 {
220 
221 	assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >>
222 	    LG_PAGE));
223 	arena_avail_tree_remove(&arena->runs_avail, arena_miscelm_get(chunk,
224 	    pageind));
225 }
226 
227 static void
228 arena_run_dirty_insert(arena_t *arena, arena_chunk_t *chunk, size_t pageind,
229     size_t npages)
230 {
231 	arena_chunk_map_misc_t *miscelm = arena_miscelm_get(chunk, pageind);
232 
233 	assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >>
234 	    LG_PAGE));
235 	assert(arena_mapbits_dirty_get(chunk, pageind) == CHUNK_MAP_DIRTY);
236 	assert(arena_mapbits_dirty_get(chunk, pageind+npages-1) ==
237 	    CHUNK_MAP_DIRTY);
238 
239 	qr_new(&miscelm->rd, rd_link);
240 	qr_meld(&arena->runs_dirty, &miscelm->rd, rd_link);
241 	arena->ndirty += npages;
242 }
243 
244 static void
245 arena_run_dirty_remove(arena_t *arena, arena_chunk_t *chunk, size_t pageind,
246     size_t npages)
247 {
248 	arena_chunk_map_misc_t *miscelm = arena_miscelm_get(chunk, pageind);
249 
250 	assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >>
251 	    LG_PAGE));
252 	assert(arena_mapbits_dirty_get(chunk, pageind) == CHUNK_MAP_DIRTY);
253 	assert(arena_mapbits_dirty_get(chunk, pageind+npages-1) ==
254 	    CHUNK_MAP_DIRTY);
255 
256 	qr_remove(&miscelm->rd, rd_link);
257 	assert(arena->ndirty >= npages);
258 	arena->ndirty -= npages;
259 }
260 
261 static size_t
262 arena_chunk_dirty_npages(const extent_node_t *node)
263 {
264 
265 	return (extent_node_size_get(node) >> LG_PAGE);
266 }
267 
268 void
269 arena_chunk_cache_maybe_insert(arena_t *arena, extent_node_t *node, bool cache)
270 {
271 
272 	if (cache) {
273 		extent_node_dirty_linkage_init(node);
274 		extent_node_dirty_insert(node, &arena->runs_dirty,
275 		    &arena->chunks_cache);
276 		arena->ndirty += arena_chunk_dirty_npages(node);
277 	}
278 }
279 
280 void
281 arena_chunk_cache_maybe_remove(arena_t *arena, extent_node_t *node, bool dirty)
282 {
283 
284 	if (dirty) {
285 		extent_node_dirty_remove(node);
286 		assert(arena->ndirty >= arena_chunk_dirty_npages(node));
287 		arena->ndirty -= arena_chunk_dirty_npages(node);
288 	}
289 }
290 
291 JEMALLOC_INLINE_C void *
292 arena_run_reg_alloc(arena_run_t *run, arena_bin_info_t *bin_info)
293 {
294 	void *ret;
295 	unsigned regind;
296 	arena_chunk_map_misc_t *miscelm;
297 	void *rpages;
298 
299 	assert(run->nfree > 0);
300 	assert(!bitmap_full(run->bitmap, &bin_info->bitmap_info));
301 
302 	regind = bitmap_sfu(run->bitmap, &bin_info->bitmap_info);
303 	miscelm = arena_run_to_miscelm(run);
304 	rpages = arena_miscelm_to_rpages(miscelm);
305 	ret = (void *)((uintptr_t)rpages + (uintptr_t)bin_info->reg0_offset +
306 	    (uintptr_t)(bin_info->reg_interval * regind));
307 	run->nfree--;
308 	return (ret);
309 }
310 
311 JEMALLOC_INLINE_C void
312 arena_run_reg_dalloc(arena_run_t *run, void *ptr)
313 {
314 	arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
315 	size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
316 	size_t mapbits = arena_mapbits_get(chunk, pageind);
317 	szind_t binind = arena_ptr_small_binind_get(ptr, mapbits);
318 	arena_bin_info_t *bin_info = &arena_bin_info[binind];
319 	unsigned regind = arena_run_regind(run, bin_info, ptr);
320 
321 	assert(run->nfree < bin_info->nregs);
322 	/* Freeing an interior pointer can cause assertion failure. */
323 	assert(((uintptr_t)ptr -
324 	    ((uintptr_t)arena_miscelm_to_rpages(arena_run_to_miscelm(run)) +
325 	    (uintptr_t)bin_info->reg0_offset)) %
326 	    (uintptr_t)bin_info->reg_interval == 0);
327 	assert((uintptr_t)ptr >=
328 	    (uintptr_t)arena_miscelm_to_rpages(arena_run_to_miscelm(run)) +
329 	    (uintptr_t)bin_info->reg0_offset);
330 	/* Freeing an unallocated pointer can cause assertion failure. */
331 	assert(bitmap_get(run->bitmap, &bin_info->bitmap_info, regind));
332 
333 	bitmap_unset(run->bitmap, &bin_info->bitmap_info, regind);
334 	run->nfree++;
335 }
336 
337 JEMALLOC_INLINE_C void
338 arena_run_zero(arena_chunk_t *chunk, size_t run_ind, size_t npages)
339 {
340 
341 	JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED((void *)((uintptr_t)chunk +
342 	    (run_ind << LG_PAGE)), (npages << LG_PAGE));
343 	memset((void *)((uintptr_t)chunk + (run_ind << LG_PAGE)), 0,
344 	    (npages << LG_PAGE));
345 }
346 
347 JEMALLOC_INLINE_C void
348 arena_run_page_mark_zeroed(arena_chunk_t *chunk, size_t run_ind)
349 {
350 
351 	JEMALLOC_VALGRIND_MAKE_MEM_DEFINED((void *)((uintptr_t)chunk + (run_ind
352 	    << LG_PAGE)), PAGE);
353 }
354 
355 JEMALLOC_INLINE_C void
356 arena_run_page_validate_zeroed(arena_chunk_t *chunk, size_t run_ind)
357 {
358 	size_t i;
359 	UNUSED size_t *p = (size_t *)((uintptr_t)chunk + (run_ind << LG_PAGE));
360 
361 	arena_run_page_mark_zeroed(chunk, run_ind);
362 	for (i = 0; i < PAGE / sizeof(size_t); i++)
363 		assert(p[i] == 0);
364 }
365 
366 static void
367 arena_cactive_update(arena_t *arena, size_t add_pages, size_t sub_pages)
368 {
369 
370 	if (config_stats) {
371 		ssize_t cactive_diff = CHUNK_CEILING((arena->nactive + add_pages
372 		    - sub_pages) << LG_PAGE) - CHUNK_CEILING(arena->nactive <<
373 		    LG_PAGE);
374 		if (cactive_diff != 0)
375 			stats_cactive_add(cactive_diff);
376 	}
377 }
378 
379 static void
380 arena_run_split_remove(arena_t *arena, arena_chunk_t *chunk, size_t run_ind,
381     size_t flag_dirty, size_t flag_decommitted, size_t need_pages)
382 {
383 	size_t total_pages, rem_pages;
384 
385 	assert(flag_dirty == 0 || flag_decommitted == 0);
386 
387 	total_pages = arena_mapbits_unallocated_size_get(chunk, run_ind) >>
388 	    LG_PAGE;
389 	assert(arena_mapbits_dirty_get(chunk, run_ind+total_pages-1) ==
390 	    flag_dirty);
391 	assert(need_pages <= total_pages);
392 	rem_pages = total_pages - need_pages;
393 
394 	arena_avail_remove(arena, chunk, run_ind, total_pages);
395 	if (flag_dirty != 0)
396 		arena_run_dirty_remove(arena, chunk, run_ind, total_pages);
397 	arena_cactive_update(arena, need_pages, 0);
398 	arena->nactive += need_pages;
399 
400 	/* Keep track of trailing unused pages for later use. */
401 	if (rem_pages > 0) {
402 		size_t flags = flag_dirty | flag_decommitted;
403 		size_t flag_unzeroed_mask = (flags == 0) ?  CHUNK_MAP_UNZEROED :
404 		    0;
405 
406 		arena_mapbits_unallocated_set(chunk, run_ind+need_pages,
407 		    (rem_pages << LG_PAGE), flags |
408 		    (arena_mapbits_unzeroed_get(chunk, run_ind+need_pages) &
409 		    flag_unzeroed_mask));
410 		arena_mapbits_unallocated_set(chunk, run_ind+total_pages-1,
411 		    (rem_pages << LG_PAGE), flags |
412 		    (arena_mapbits_unzeroed_get(chunk, run_ind+total_pages-1) &
413 		    flag_unzeroed_mask));
414 		if (flag_dirty != 0) {
415 			arena_run_dirty_insert(arena, chunk, run_ind+need_pages,
416 			    rem_pages);
417 		}
418 		arena_avail_insert(arena, chunk, run_ind+need_pages, rem_pages);
419 	}
420 }
421 
422 static bool
423 arena_run_split_large_helper(arena_t *arena, arena_run_t *run, size_t size,
424     bool remove, bool zero)
425 {
426 	arena_chunk_t *chunk;
427 	arena_chunk_map_misc_t *miscelm;
428 	size_t flag_dirty, flag_decommitted, run_ind, need_pages;
429 	size_t flag_unzeroed_mask;
430 
431 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
432 	miscelm = arena_run_to_miscelm(run);
433 	run_ind = arena_miscelm_to_pageind(miscelm);
434 	flag_dirty = arena_mapbits_dirty_get(chunk, run_ind);
435 	flag_decommitted = arena_mapbits_decommitted_get(chunk, run_ind);
436 	need_pages = (size >> LG_PAGE);
437 	assert(need_pages > 0);
438 
439 	if (flag_decommitted != 0 && arena->chunk_hooks.commit(chunk, chunksize,
440 	    run_ind << LG_PAGE, size, arena->ind))
441 		return (true);
442 
443 	if (remove) {
444 		arena_run_split_remove(arena, chunk, run_ind, flag_dirty,
445 		    flag_decommitted, need_pages);
446 	}
447 
448 	if (zero) {
449 		if (flag_decommitted != 0) {
450 			/* The run is untouched, and therefore zeroed. */
451 			JEMALLOC_VALGRIND_MAKE_MEM_DEFINED((void
452 			    *)((uintptr_t)chunk + (run_ind << LG_PAGE)),
453 			    (need_pages << LG_PAGE));
454 		} else if (flag_dirty != 0) {
455 			/* The run is dirty, so all pages must be zeroed. */
456 			arena_run_zero(chunk, run_ind, need_pages);
457 		} else {
458 			/*
459 			 * The run is clean, so some pages may be zeroed (i.e.
460 			 * never before touched).
461 			 */
462 			size_t i;
463 			for (i = 0; i < need_pages; i++) {
464 				if (arena_mapbits_unzeroed_get(chunk, run_ind+i)
465 				    != 0)
466 					arena_run_zero(chunk, run_ind+i, 1);
467 				else if (config_debug) {
468 					arena_run_page_validate_zeroed(chunk,
469 					    run_ind+i);
470 				} else {
471 					arena_run_page_mark_zeroed(chunk,
472 					    run_ind+i);
473 				}
474 			}
475 		}
476 	} else {
477 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED((void *)((uintptr_t)chunk +
478 		    (run_ind << LG_PAGE)), (need_pages << LG_PAGE));
479 	}
480 
481 	/*
482 	 * Set the last element first, in case the run only contains one page
483 	 * (i.e. both statements set the same element).
484 	 */
485 	flag_unzeroed_mask = (flag_dirty | flag_decommitted) == 0 ?
486 	    CHUNK_MAP_UNZEROED : 0;
487 	arena_mapbits_large_set(chunk, run_ind+need_pages-1, 0, flag_dirty |
488 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
489 	    run_ind+need_pages-1)));
490 	arena_mapbits_large_set(chunk, run_ind, size, flag_dirty |
491 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk, run_ind)));
492 	return (false);
493 }
494 
495 static bool
496 arena_run_split_large(arena_t *arena, arena_run_t *run, size_t size, bool zero)
497 {
498 
499 	return (arena_run_split_large_helper(arena, run, size, true, zero));
500 }
501 
502 static bool
503 arena_run_init_large(arena_t *arena, arena_run_t *run, size_t size, bool zero)
504 {
505 
506 	return (arena_run_split_large_helper(arena, run, size, false, zero));
507 }
508 
509 static bool
510 arena_run_split_small(arena_t *arena, arena_run_t *run, size_t size,
511     szind_t binind)
512 {
513 	arena_chunk_t *chunk;
514 	arena_chunk_map_misc_t *miscelm;
515 	size_t flag_dirty, flag_decommitted, run_ind, need_pages, i;
516 
517 	assert(binind != BININD_INVALID);
518 
519 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
520 	miscelm = arena_run_to_miscelm(run);
521 	run_ind = arena_miscelm_to_pageind(miscelm);
522 	flag_dirty = arena_mapbits_dirty_get(chunk, run_ind);
523 	flag_decommitted = arena_mapbits_decommitted_get(chunk, run_ind);
524 	need_pages = (size >> LG_PAGE);
525 	assert(need_pages > 0);
526 
527 	if (flag_decommitted != 0 && arena->chunk_hooks.commit(chunk, chunksize,
528 	    run_ind << LG_PAGE, size, arena->ind))
529 		return (true);
530 
531 	arena_run_split_remove(arena, chunk, run_ind, flag_dirty,
532 	    flag_decommitted, need_pages);
533 
534 	for (i = 0; i < need_pages; i++) {
535 		size_t flag_unzeroed = arena_mapbits_unzeroed_get(chunk,
536 		    run_ind+i);
537 		arena_mapbits_small_set(chunk, run_ind+i, i, binind,
538 		    flag_unzeroed);
539 		if (config_debug && flag_dirty == 0 && flag_unzeroed == 0)
540 			arena_run_page_validate_zeroed(chunk, run_ind+i);
541 	}
542 	JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED((void *)((uintptr_t)chunk +
543 	    (run_ind << LG_PAGE)), (need_pages << LG_PAGE));
544 	return (false);
545 }
546 
547 static arena_chunk_t *
548 arena_chunk_init_spare(arena_t *arena)
549 {
550 	arena_chunk_t *chunk;
551 
552 	assert(arena->spare != NULL);
553 
554 	chunk = arena->spare;
555 	arena->spare = NULL;
556 
557 	assert(arena_mapbits_allocated_get(chunk, map_bias) == 0);
558 	assert(arena_mapbits_allocated_get(chunk, chunk_npages-1) == 0);
559 	assert(arena_mapbits_unallocated_size_get(chunk, map_bias) ==
560 	    arena_maxrun);
561 	assert(arena_mapbits_unallocated_size_get(chunk, chunk_npages-1) ==
562 	    arena_maxrun);
563 	assert(arena_mapbits_dirty_get(chunk, map_bias) ==
564 	    arena_mapbits_dirty_get(chunk, chunk_npages-1));
565 
566 	return (chunk);
567 }
568 
569 static bool
570 arena_chunk_register(arena_t *arena, arena_chunk_t *chunk, bool zero)
571 {
572 
573 	/*
574 	 * The extent node notion of "committed" doesn't directly apply to
575 	 * arena chunks.  Arbitrarily mark them as committed.  The commit state
576 	 * of runs is tracked individually, and upon chunk deallocation the
577 	 * entire chunk is in a consistent commit state.
578 	 */
579 	extent_node_init(&chunk->node, arena, chunk, chunksize, zero, true);
580 	extent_node_achunk_set(&chunk->node, true);
581 	return (chunk_register(chunk, &chunk->node));
582 }
583 
584 static arena_chunk_t *
585 arena_chunk_alloc_internal_hard(arena_t *arena, chunk_hooks_t *chunk_hooks,
586     bool *zero, bool *commit)
587 {
588 	arena_chunk_t *chunk;
589 
590 	malloc_mutex_unlock(&arena->lock);
591 
592 	chunk = (arena_chunk_t *)chunk_alloc_wrapper(arena, chunk_hooks, NULL,
593 	    chunksize, chunksize, zero, commit);
594 	if (chunk != NULL && !*commit) {
595 		/* Commit header. */
596 		if (chunk_hooks->commit(chunk, chunksize, 0, map_bias <<
597 		    LG_PAGE, arena->ind)) {
598 			chunk_dalloc_wrapper(arena, chunk_hooks,
599 			    (void *)chunk, chunksize, *commit);
600 			chunk = NULL;
601 		}
602 	}
603 	if (chunk != NULL && arena_chunk_register(arena, chunk, *zero)) {
604 		if (!*commit) {
605 			/* Undo commit of header. */
606 			chunk_hooks->decommit(chunk, chunksize, 0, map_bias <<
607 			    LG_PAGE, arena->ind);
608 		}
609 		chunk_dalloc_wrapper(arena, chunk_hooks, (void *)chunk,
610 		    chunksize, *commit);
611 		chunk = NULL;
612 	}
613 
614 	malloc_mutex_lock(&arena->lock);
615 	return (chunk);
616 }
617 
618 static arena_chunk_t *
619 arena_chunk_alloc_internal(arena_t *arena, bool *zero, bool *commit)
620 {
621 	arena_chunk_t *chunk;
622 	chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
623 
624 	chunk = chunk_alloc_cache(arena, &chunk_hooks, NULL, chunksize,
625 	    chunksize, zero, true);
626 	if (chunk != NULL) {
627 		if (arena_chunk_register(arena, chunk, *zero)) {
628 			chunk_dalloc_cache(arena, &chunk_hooks, chunk,
629 			    chunksize, true);
630 			return (NULL);
631 		}
632 		*commit = true;
633 	}
634 	if (chunk == NULL) {
635 		chunk = arena_chunk_alloc_internal_hard(arena, &chunk_hooks,
636 		    zero, commit);
637 	}
638 
639 	if (config_stats && chunk != NULL) {
640 		arena->stats.mapped += chunksize;
641 		arena->stats.metadata_mapped += (map_bias << LG_PAGE);
642 	}
643 
644 	return (chunk);
645 }
646 
647 static arena_chunk_t *
648 arena_chunk_init_hard(arena_t *arena)
649 {
650 	arena_chunk_t *chunk;
651 	bool zero, commit;
652 	size_t flag_unzeroed, flag_decommitted, i;
653 
654 	assert(arena->spare == NULL);
655 
656 	zero = false;
657 	commit = false;
658 	chunk = arena_chunk_alloc_internal(arena, &zero, &commit);
659 	if (chunk == NULL)
660 		return (NULL);
661 
662 	/*
663 	 * Initialize the map to contain one maximal free untouched run.  Mark
664 	 * the pages as zeroed if chunk_alloc() returned a zeroed or decommitted
665 	 * chunk.
666 	 */
667 	flag_unzeroed = (zero || !commit) ? 0 : CHUNK_MAP_UNZEROED;
668 	flag_decommitted = commit ? 0 : CHUNK_MAP_DECOMMITTED;
669 	arena_mapbits_unallocated_set(chunk, map_bias, arena_maxrun,
670 	    flag_unzeroed | flag_decommitted);
671 	/*
672 	 * There is no need to initialize the internal page map entries unless
673 	 * the chunk is not zeroed.
674 	 */
675 	if (!zero) {
676 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(
677 		    (void *)arena_bitselm_get(chunk, map_bias+1),
678 		    (size_t)((uintptr_t) arena_bitselm_get(chunk,
679 		    chunk_npages-1) - (uintptr_t)arena_bitselm_get(chunk,
680 		    map_bias+1)));
681 		for (i = map_bias+1; i < chunk_npages-1; i++)
682 			arena_mapbits_internal_set(chunk, i, flag_unzeroed);
683 	} else {
684 		JEMALLOC_VALGRIND_MAKE_MEM_DEFINED((void
685 		    *)arena_bitselm_get(chunk, map_bias+1), (size_t)((uintptr_t)
686 		    arena_bitselm_get(chunk, chunk_npages-1) -
687 		    (uintptr_t)arena_bitselm_get(chunk, map_bias+1)));
688 		if (config_debug) {
689 			for (i = map_bias+1; i < chunk_npages-1; i++) {
690 				assert(arena_mapbits_unzeroed_get(chunk, i) ==
691 				    flag_unzeroed);
692 			}
693 		}
694 	}
695 	arena_mapbits_unallocated_set(chunk, chunk_npages-1, arena_maxrun,
696 	    flag_unzeroed);
697 
698 	return (chunk);
699 }
700 
701 static arena_chunk_t *
702 arena_chunk_alloc(arena_t *arena)
703 {
704 	arena_chunk_t *chunk;
705 
706 	if (arena->spare != NULL)
707 		chunk = arena_chunk_init_spare(arena);
708 	else {
709 		chunk = arena_chunk_init_hard(arena);
710 		if (chunk == NULL)
711 			return (NULL);
712 	}
713 
714 	/* Insert the run into the runs_avail tree. */
715 	arena_avail_insert(arena, chunk, map_bias, chunk_npages-map_bias);
716 
717 	return (chunk);
718 }
719 
720 static void
721 arena_chunk_dalloc(arena_t *arena, arena_chunk_t *chunk)
722 {
723 
724 	assert(arena_mapbits_allocated_get(chunk, map_bias) == 0);
725 	assert(arena_mapbits_allocated_get(chunk, chunk_npages-1) == 0);
726 	assert(arena_mapbits_unallocated_size_get(chunk, map_bias) ==
727 	    arena_maxrun);
728 	assert(arena_mapbits_unallocated_size_get(chunk, chunk_npages-1) ==
729 	    arena_maxrun);
730 	assert(arena_mapbits_dirty_get(chunk, map_bias) ==
731 	    arena_mapbits_dirty_get(chunk, chunk_npages-1));
732 	assert(arena_mapbits_decommitted_get(chunk, map_bias) ==
733 	    arena_mapbits_decommitted_get(chunk, chunk_npages-1));
734 
735 	/*
736 	 * Remove run from the runs_avail tree, so that the arena does not use
737 	 * it.
738 	 */
739 	arena_avail_remove(arena, chunk, map_bias, chunk_npages-map_bias);
740 
741 	if (arena->spare != NULL) {
742 		arena_chunk_t *spare = arena->spare;
743 		chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
744 		bool committed;
745 
746 		arena->spare = chunk;
747 		if (arena_mapbits_dirty_get(spare, map_bias) != 0) {
748 			arena_run_dirty_remove(arena, spare, map_bias,
749 			    chunk_npages-map_bias);
750 		}
751 
752 		chunk_deregister(spare, &spare->node);
753 
754 		committed = (arena_mapbits_decommitted_get(spare, map_bias) ==
755 		    0);
756 		if (!committed) {
757 			/*
758 			 * Decommit the header.  Mark the chunk as decommitted
759 			 * even if header decommit fails, since treating a
760 			 * partially committed chunk as committed has a high
761 			 * potential for causing later access of decommitted
762 			 * memory.
763 			 */
764 			chunk_hooks = chunk_hooks_get(arena);
765 			chunk_hooks.decommit(spare, chunksize, 0, map_bias <<
766 			    LG_PAGE, arena->ind);
767 		}
768 
769 		chunk_dalloc_cache(arena, &chunk_hooks, (void *)spare,
770 		    chunksize, committed);
771 
772 		if (config_stats) {
773 			arena->stats.mapped -= chunksize;
774 			arena->stats.metadata_mapped -= (map_bias << LG_PAGE);
775 		}
776 	} else
777 		arena->spare = chunk;
778 }
779 
780 static void
781 arena_huge_malloc_stats_update(arena_t *arena, size_t usize)
782 {
783 	szind_t index = size2index(usize) - nlclasses - NBINS;
784 
785 	cassert(config_stats);
786 
787 	arena->stats.nmalloc_huge++;
788 	arena->stats.allocated_huge += usize;
789 	arena->stats.hstats[index].nmalloc++;
790 	arena->stats.hstats[index].curhchunks++;
791 }
792 
793 static void
794 arena_huge_malloc_stats_update_undo(arena_t *arena, size_t usize)
795 {
796 	szind_t index = size2index(usize) - nlclasses - NBINS;
797 
798 	cassert(config_stats);
799 
800 	arena->stats.nmalloc_huge--;
801 	arena->stats.allocated_huge -= usize;
802 	arena->stats.hstats[index].nmalloc--;
803 	arena->stats.hstats[index].curhchunks--;
804 }
805 
806 static void
807 arena_huge_dalloc_stats_update(arena_t *arena, size_t usize)
808 {
809 	szind_t index = size2index(usize) - nlclasses - NBINS;
810 
811 	cassert(config_stats);
812 
813 	arena->stats.ndalloc_huge++;
814 	arena->stats.allocated_huge -= usize;
815 	arena->stats.hstats[index].ndalloc++;
816 	arena->stats.hstats[index].curhchunks--;
817 }
818 
819 static void
820 arena_huge_dalloc_stats_update_undo(arena_t *arena, size_t usize)
821 {
822 	szind_t index = size2index(usize) - nlclasses - NBINS;
823 
824 	cassert(config_stats);
825 
826 	arena->stats.ndalloc_huge--;
827 	arena->stats.allocated_huge += usize;
828 	arena->stats.hstats[index].ndalloc--;
829 	arena->stats.hstats[index].curhchunks++;
830 }
831 
832 static void
833 arena_huge_ralloc_stats_update(arena_t *arena, size_t oldsize, size_t usize)
834 {
835 
836 	arena_huge_dalloc_stats_update(arena, oldsize);
837 	arena_huge_malloc_stats_update(arena, usize);
838 }
839 
840 static void
841 arena_huge_ralloc_stats_update_undo(arena_t *arena, size_t oldsize,
842     size_t usize)
843 {
844 
845 	arena_huge_dalloc_stats_update_undo(arena, oldsize);
846 	arena_huge_malloc_stats_update_undo(arena, usize);
847 }
848 
849 extent_node_t *
850 arena_node_alloc(arena_t *arena)
851 {
852 	extent_node_t *node;
853 
854 	malloc_mutex_lock(&arena->node_cache_mtx);
855 	node = ql_last(&arena->node_cache, ql_link);
856 	if (node == NULL) {
857 		malloc_mutex_unlock(&arena->node_cache_mtx);
858 		return (base_alloc(sizeof(extent_node_t)));
859 	}
860 	ql_tail_remove(&arena->node_cache, extent_node_t, ql_link);
861 	malloc_mutex_unlock(&arena->node_cache_mtx);
862 	return (node);
863 }
864 
865 void
866 arena_node_dalloc(arena_t *arena, extent_node_t *node)
867 {
868 
869 	malloc_mutex_lock(&arena->node_cache_mtx);
870 	ql_elm_new(node, ql_link);
871 	ql_tail_insert(&arena->node_cache, node, ql_link);
872 	malloc_mutex_unlock(&arena->node_cache_mtx);
873 }
874 
875 static void *
876 arena_chunk_alloc_huge_hard(arena_t *arena, chunk_hooks_t *chunk_hooks,
877     size_t usize, size_t alignment, bool *zero, size_t csize)
878 {
879 	void *ret;
880 	bool commit = true;
881 
882 	ret = chunk_alloc_wrapper(arena, chunk_hooks, NULL, csize, alignment,
883 	    zero, &commit);
884 	if (ret == NULL) {
885 		/* Revert optimistic stats updates. */
886 		malloc_mutex_lock(&arena->lock);
887 		if (config_stats) {
888 			arena_huge_malloc_stats_update_undo(arena, usize);
889 			arena->stats.mapped -= usize;
890 		}
891 		arena->nactive -= (usize >> LG_PAGE);
892 		malloc_mutex_unlock(&arena->lock);
893 	}
894 
895 	return (ret);
896 }
897 
898 void *
899 arena_chunk_alloc_huge(arena_t *arena, size_t usize, size_t alignment,
900     bool *zero)
901 {
902 	void *ret;
903 	chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
904 	size_t csize = CHUNK_CEILING(usize);
905 
906 	malloc_mutex_lock(&arena->lock);
907 
908 	/* Optimistically update stats. */
909 	if (config_stats) {
910 		arena_huge_malloc_stats_update(arena, usize);
911 		arena->stats.mapped += usize;
912 	}
913 	arena->nactive += (usize >> LG_PAGE);
914 
915 	ret = chunk_alloc_cache(arena, &chunk_hooks, NULL, csize, alignment,
916 	    zero, true);
917 	malloc_mutex_unlock(&arena->lock);
918 	if (ret == NULL) {
919 		ret = arena_chunk_alloc_huge_hard(arena, &chunk_hooks, usize,
920 		    alignment, zero, csize);
921 	}
922 
923 	if (config_stats && ret != NULL)
924 		stats_cactive_add(usize);
925 	return (ret);
926 }
927 
928 void
929 arena_chunk_dalloc_huge(arena_t *arena, void *chunk, size_t usize)
930 {
931 	chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
932 	size_t csize;
933 
934 	csize = CHUNK_CEILING(usize);
935 	malloc_mutex_lock(&arena->lock);
936 	if (config_stats) {
937 		arena_huge_dalloc_stats_update(arena, usize);
938 		arena->stats.mapped -= usize;
939 		stats_cactive_sub(usize);
940 	}
941 	arena->nactive -= (usize >> LG_PAGE);
942 
943 	chunk_dalloc_cache(arena, &chunk_hooks, chunk, csize, true);
944 	malloc_mutex_unlock(&arena->lock);
945 }
946 
947 void
948 arena_chunk_ralloc_huge_similar(arena_t *arena, void *chunk, size_t oldsize,
949     size_t usize)
950 {
951 
952 	assert(CHUNK_CEILING(oldsize) == CHUNK_CEILING(usize));
953 	assert(oldsize != usize);
954 
955 	malloc_mutex_lock(&arena->lock);
956 	if (config_stats)
957 		arena_huge_ralloc_stats_update(arena, oldsize, usize);
958 	if (oldsize < usize) {
959 		size_t udiff = usize - oldsize;
960 		arena->nactive += udiff >> LG_PAGE;
961 		if (config_stats)
962 			stats_cactive_add(udiff);
963 	} else {
964 		size_t udiff = oldsize - usize;
965 		arena->nactive -= udiff >> LG_PAGE;
966 		if (config_stats)
967 			stats_cactive_sub(udiff);
968 	}
969 	malloc_mutex_unlock(&arena->lock);
970 }
971 
972 void
973 arena_chunk_ralloc_huge_shrink(arena_t *arena, void *chunk, size_t oldsize,
974     size_t usize)
975 {
976 	size_t udiff = oldsize - usize;
977 	size_t cdiff = CHUNK_CEILING(oldsize) - CHUNK_CEILING(usize);
978 
979 	malloc_mutex_lock(&arena->lock);
980 	if (config_stats) {
981 		arena_huge_ralloc_stats_update(arena, oldsize, usize);
982 		if (cdiff != 0) {
983 			arena->stats.mapped -= cdiff;
984 			stats_cactive_sub(udiff);
985 		}
986 	}
987 	arena->nactive -= udiff >> LG_PAGE;
988 
989 	if (cdiff != 0) {
990 		chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
991 		void *nchunk = (void *)((uintptr_t)chunk +
992 		    CHUNK_CEILING(usize));
993 
994 		chunk_dalloc_cache(arena, &chunk_hooks, nchunk, cdiff, true);
995 	}
996 	malloc_mutex_unlock(&arena->lock);
997 }
998 
999 static bool
1000 arena_chunk_ralloc_huge_expand_hard(arena_t *arena, chunk_hooks_t *chunk_hooks,
1001     void *chunk, size_t oldsize, size_t usize, bool *zero, void *nchunk,
1002     size_t udiff, size_t cdiff)
1003 {
1004 	bool err;
1005 	bool commit = true;
1006 
1007 	err = (chunk_alloc_wrapper(arena, chunk_hooks, nchunk, cdiff, chunksize,
1008 	    zero, &commit) == NULL);
1009 	if (err) {
1010 		/* Revert optimistic stats updates. */
1011 		malloc_mutex_lock(&arena->lock);
1012 		if (config_stats) {
1013 			arena_huge_ralloc_stats_update_undo(arena, oldsize,
1014 			    usize);
1015 			arena->stats.mapped -= cdiff;
1016 		}
1017 		arena->nactive -= (udiff >> LG_PAGE);
1018 		malloc_mutex_unlock(&arena->lock);
1019 	} else if (chunk_hooks->merge(chunk, CHUNK_CEILING(oldsize), nchunk,
1020 	    cdiff, true, arena->ind)) {
1021 		chunk_dalloc_arena(arena, chunk_hooks, nchunk, cdiff, *zero,
1022 		    true);
1023 		err = true;
1024 	}
1025 	return (err);
1026 }
1027 
1028 bool
1029 arena_chunk_ralloc_huge_expand(arena_t *arena, void *chunk, size_t oldsize,
1030     size_t usize, bool *zero)
1031 {
1032 	bool err;
1033 	chunk_hooks_t chunk_hooks = chunk_hooks_get(arena);
1034 	void *nchunk = (void *)((uintptr_t)chunk + CHUNK_CEILING(oldsize));
1035 	size_t udiff = usize - oldsize;
1036 	size_t cdiff = CHUNK_CEILING(usize) - CHUNK_CEILING(oldsize);
1037 
1038 	malloc_mutex_lock(&arena->lock);
1039 
1040 	/* Optimistically update stats. */
1041 	if (config_stats) {
1042 		arena_huge_ralloc_stats_update(arena, oldsize, usize);
1043 		arena->stats.mapped += cdiff;
1044 	}
1045 	arena->nactive += (udiff >> LG_PAGE);
1046 
1047 	err = (chunk_alloc_cache(arena, &arena->chunk_hooks, nchunk, cdiff,
1048 	    chunksize, zero, true) == NULL);
1049 	malloc_mutex_unlock(&arena->lock);
1050 	if (err) {
1051 		err = arena_chunk_ralloc_huge_expand_hard(arena, &chunk_hooks,
1052 		    chunk, oldsize, usize, zero, nchunk, udiff,
1053 		    cdiff);
1054 	} else if (chunk_hooks.merge(chunk, CHUNK_CEILING(oldsize), nchunk,
1055 	    cdiff, true, arena->ind)) {
1056 		chunk_dalloc_arena(arena, &chunk_hooks, nchunk, cdiff, *zero,
1057 		    true);
1058 		err = true;
1059 	}
1060 
1061 	if (config_stats && !err)
1062 		stats_cactive_add(udiff);
1063 	return (err);
1064 }
1065 
1066 /*
1067  * Do first-best-fit run selection, i.e. select the lowest run that best fits.
1068  * Run sizes are quantized, so not all candidate runs are necessarily exactly
1069  * the same size.
1070  */
1071 static arena_run_t *
1072 arena_run_first_best_fit(arena_t *arena, size_t size)
1073 {
1074 	size_t search_size = run_quantize_first(size);
1075 	arena_chunk_map_misc_t *key = arena_miscelm_key_create(search_size);
1076 	arena_chunk_map_misc_t *miscelm =
1077 	    arena_avail_tree_nsearch(&arena->runs_avail, key);
1078 	if (miscelm == NULL)
1079 		return (NULL);
1080 	return (&miscelm->run);
1081 }
1082 
1083 static arena_run_t *
1084 arena_run_alloc_large_helper(arena_t *arena, size_t size, bool zero)
1085 {
1086 	arena_run_t *run = arena_run_first_best_fit(arena, s2u(size));
1087 	if (run != NULL) {
1088 		if (arena_run_split_large(arena, run, size, zero))
1089 			run = NULL;
1090 	}
1091 	return (run);
1092 }
1093 
1094 static arena_run_t *
1095 arena_run_alloc_large(arena_t *arena, size_t size, bool zero)
1096 {
1097 	arena_chunk_t *chunk;
1098 	arena_run_t *run;
1099 
1100 	assert(size <= arena_maxrun);
1101 	assert(size == PAGE_CEILING(size));
1102 
1103 	/* Search the arena's chunks for the lowest best fit. */
1104 	run = arena_run_alloc_large_helper(arena, size, zero);
1105 	if (run != NULL)
1106 		return (run);
1107 
1108 	/*
1109 	 * No usable runs.  Create a new chunk from which to allocate the run.
1110 	 */
1111 	chunk = arena_chunk_alloc(arena);
1112 	if (chunk != NULL) {
1113 		run = &arena_miscelm_get(chunk, map_bias)->run;
1114 		if (arena_run_split_large(arena, run, size, zero))
1115 			run = NULL;
1116 		return (run);
1117 	}
1118 
1119 	/*
1120 	 * arena_chunk_alloc() failed, but another thread may have made
1121 	 * sufficient memory available while this one dropped arena->lock in
1122 	 * arena_chunk_alloc(), so search one more time.
1123 	 */
1124 	return (arena_run_alloc_large_helper(arena, size, zero));
1125 }
1126 
1127 static arena_run_t *
1128 arena_run_alloc_small_helper(arena_t *arena, size_t size, szind_t binind)
1129 {
1130 	arena_run_t *run = arena_run_first_best_fit(arena, size);
1131 	if (run != NULL) {
1132 		if (arena_run_split_small(arena, run, size, binind))
1133 			run = NULL;
1134 	}
1135 	return (run);
1136 }
1137 
1138 static arena_run_t *
1139 arena_run_alloc_small(arena_t *arena, size_t size, szind_t binind)
1140 {
1141 	arena_chunk_t *chunk;
1142 	arena_run_t *run;
1143 
1144 	assert(size <= arena_maxrun);
1145 	assert(size == PAGE_CEILING(size));
1146 	assert(binind != BININD_INVALID);
1147 
1148 	/* Search the arena's chunks for the lowest best fit. */
1149 	run = arena_run_alloc_small_helper(arena, size, binind);
1150 	if (run != NULL)
1151 		return (run);
1152 
1153 	/*
1154 	 * No usable runs.  Create a new chunk from which to allocate the run.
1155 	 */
1156 	chunk = arena_chunk_alloc(arena);
1157 	if (chunk != NULL) {
1158 		run = &arena_miscelm_get(chunk, map_bias)->run;
1159 		if (arena_run_split_small(arena, run, size, binind))
1160 			run = NULL;
1161 		return (run);
1162 	}
1163 
1164 	/*
1165 	 * arena_chunk_alloc() failed, but another thread may have made
1166 	 * sufficient memory available while this one dropped arena->lock in
1167 	 * arena_chunk_alloc(), so search one more time.
1168 	 */
1169 	return (arena_run_alloc_small_helper(arena, size, binind));
1170 }
1171 
1172 static bool
1173 arena_lg_dirty_mult_valid(ssize_t lg_dirty_mult)
1174 {
1175 
1176 	return (lg_dirty_mult >= -1 && lg_dirty_mult < (ssize_t)(sizeof(size_t)
1177 	    << 3));
1178 }
1179 
1180 ssize_t
1181 arena_lg_dirty_mult_get(arena_t *arena)
1182 {
1183 	ssize_t lg_dirty_mult;
1184 
1185 	malloc_mutex_lock(&arena->lock);
1186 	lg_dirty_mult = arena->lg_dirty_mult;
1187 	malloc_mutex_unlock(&arena->lock);
1188 
1189 	return (lg_dirty_mult);
1190 }
1191 
1192 bool
1193 arena_lg_dirty_mult_set(arena_t *arena, ssize_t lg_dirty_mult)
1194 {
1195 
1196 	if (!arena_lg_dirty_mult_valid(lg_dirty_mult))
1197 		return (true);
1198 
1199 	malloc_mutex_lock(&arena->lock);
1200 	arena->lg_dirty_mult = lg_dirty_mult;
1201 	arena_maybe_purge(arena);
1202 	malloc_mutex_unlock(&arena->lock);
1203 
1204 	return (false);
1205 }
1206 
1207 void
1208 arena_maybe_purge(arena_t *arena)
1209 {
1210 
1211 	/* Don't purge if the option is disabled. */
1212 	if (arena->lg_dirty_mult < 0)
1213 		return;
1214 	/* Don't recursively purge. */
1215 	if (arena->purging)
1216 		return;
1217 	/*
1218 	 * Iterate, since preventing recursive purging could otherwise leave too
1219 	 * many dirty pages.
1220 	 */
1221 	while (true) {
1222 		size_t threshold = (arena->nactive >> arena->lg_dirty_mult);
1223 		if (threshold < chunk_npages)
1224 			threshold = chunk_npages;
1225 		/*
1226 		 * Don't purge unless the number of purgeable pages exceeds the
1227 		 * threshold.
1228 		 */
1229 		if (arena->ndirty <= threshold)
1230 			return;
1231 		arena_purge(arena, false);
1232 	}
1233 }
1234 
1235 static size_t
1236 arena_dirty_count(arena_t *arena)
1237 {
1238 	size_t ndirty = 0;
1239 	arena_runs_dirty_link_t *rdelm;
1240 	extent_node_t *chunkselm;
1241 
1242 	for (rdelm = qr_next(&arena->runs_dirty, rd_link),
1243 	    chunkselm = qr_next(&arena->chunks_cache, cc_link);
1244 	    rdelm != &arena->runs_dirty; rdelm = qr_next(rdelm, rd_link)) {
1245 		size_t npages;
1246 
1247 		if (rdelm == &chunkselm->rd) {
1248 			npages = extent_node_size_get(chunkselm) >> LG_PAGE;
1249 			chunkselm = qr_next(chunkselm, cc_link);
1250 		} else {
1251 			arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(
1252 			    rdelm);
1253 			arena_chunk_map_misc_t *miscelm =
1254 			    arena_rd_to_miscelm(rdelm);
1255 			size_t pageind = arena_miscelm_to_pageind(miscelm);
1256 			assert(arena_mapbits_allocated_get(chunk, pageind) ==
1257 			    0);
1258 			assert(arena_mapbits_large_get(chunk, pageind) == 0);
1259 			assert(arena_mapbits_dirty_get(chunk, pageind) != 0);
1260 			npages = arena_mapbits_unallocated_size_get(chunk,
1261 			    pageind) >> LG_PAGE;
1262 		}
1263 		ndirty += npages;
1264 	}
1265 
1266 	return (ndirty);
1267 }
1268 
1269 static size_t
1270 arena_compute_npurge(arena_t *arena, bool all)
1271 {
1272 	size_t npurge;
1273 
1274 	/*
1275 	 * Compute the minimum number of pages that this thread should try to
1276 	 * purge.
1277 	 */
1278 	if (!all) {
1279 		size_t threshold = (arena->nactive >> arena->lg_dirty_mult);
1280 		threshold = threshold < chunk_npages ? chunk_npages : threshold;
1281 
1282 		npurge = arena->ndirty - threshold;
1283 	} else
1284 		npurge = arena->ndirty;
1285 
1286 	return (npurge);
1287 }
1288 
1289 static size_t
1290 arena_stash_dirty(arena_t *arena, chunk_hooks_t *chunk_hooks, bool all,
1291     size_t npurge, arena_runs_dirty_link_t *purge_runs_sentinel,
1292     extent_node_t *purge_chunks_sentinel)
1293 {
1294 	arena_runs_dirty_link_t *rdelm, *rdelm_next;
1295 	extent_node_t *chunkselm;
1296 	size_t nstashed = 0;
1297 
1298 	/* Stash at least npurge pages. */
1299 	for (rdelm = qr_next(&arena->runs_dirty, rd_link),
1300 	    chunkselm = qr_next(&arena->chunks_cache, cc_link);
1301 	    rdelm != &arena->runs_dirty; rdelm = rdelm_next) {
1302 		size_t npages;
1303 		rdelm_next = qr_next(rdelm, rd_link);
1304 
1305 		if (rdelm == &chunkselm->rd) {
1306 			extent_node_t *chunkselm_next;
1307 			bool zero;
1308 			UNUSED void *chunk;
1309 
1310 			chunkselm_next = qr_next(chunkselm, cc_link);
1311 			/*
1312 			 * Allocate.  chunkselm remains valid due to the
1313 			 * dalloc_node=false argument to chunk_alloc_cache().
1314 			 */
1315 			zero = false;
1316 			chunk = chunk_alloc_cache(arena, chunk_hooks,
1317 			    extent_node_addr_get(chunkselm),
1318 			    extent_node_size_get(chunkselm), chunksize, &zero,
1319 			    false);
1320 			assert(chunk == extent_node_addr_get(chunkselm));
1321 			assert(zero == extent_node_zeroed_get(chunkselm));
1322 			extent_node_dirty_insert(chunkselm, purge_runs_sentinel,
1323 			    purge_chunks_sentinel);
1324 			npages = extent_node_size_get(chunkselm) >> LG_PAGE;
1325 			chunkselm = chunkselm_next;
1326 		} else {
1327 			arena_chunk_t *chunk =
1328 			    (arena_chunk_t *)CHUNK_ADDR2BASE(rdelm);
1329 			arena_chunk_map_misc_t *miscelm =
1330 			    arena_rd_to_miscelm(rdelm);
1331 			size_t pageind = arena_miscelm_to_pageind(miscelm);
1332 			arena_run_t *run = &miscelm->run;
1333 			size_t run_size =
1334 			    arena_mapbits_unallocated_size_get(chunk, pageind);
1335 
1336 			npages = run_size >> LG_PAGE;
1337 
1338 			assert(pageind + npages <= chunk_npages);
1339 			assert(arena_mapbits_dirty_get(chunk, pageind) ==
1340 			    arena_mapbits_dirty_get(chunk, pageind+npages-1));
1341 
1342 			/*
1343 			 * If purging the spare chunk's run, make it available
1344 			 * prior to allocation.
1345 			 */
1346 			if (chunk == arena->spare)
1347 				arena_chunk_alloc(arena);
1348 
1349 			/* Temporarily allocate the free dirty run. */
1350 			arena_run_split_large(arena, run, run_size, false);
1351 			/* Stash. */
1352 			if (false)
1353 				qr_new(rdelm, rd_link); /* Redundant. */
1354 			else {
1355 				assert(qr_next(rdelm, rd_link) == rdelm);
1356 				assert(qr_prev(rdelm, rd_link) == rdelm);
1357 			}
1358 			qr_meld(purge_runs_sentinel, rdelm, rd_link);
1359 		}
1360 
1361 		nstashed += npages;
1362 		if (!all && nstashed >= npurge)
1363 			break;
1364 	}
1365 
1366 	return (nstashed);
1367 }
1368 
1369 static size_t
1370 arena_purge_stashed(arena_t *arena, chunk_hooks_t *chunk_hooks,
1371     arena_runs_dirty_link_t *purge_runs_sentinel,
1372     extent_node_t *purge_chunks_sentinel)
1373 {
1374 	size_t npurged, nmadvise;
1375 	arena_runs_dirty_link_t *rdelm;
1376 	extent_node_t *chunkselm;
1377 
1378 	if (config_stats)
1379 		nmadvise = 0;
1380 	npurged = 0;
1381 
1382 	malloc_mutex_unlock(&arena->lock);
1383 	for (rdelm = qr_next(purge_runs_sentinel, rd_link),
1384 	    chunkselm = qr_next(purge_chunks_sentinel, cc_link);
1385 	    rdelm != purge_runs_sentinel; rdelm = qr_next(rdelm, rd_link)) {
1386 		size_t npages;
1387 
1388 		if (rdelm == &chunkselm->rd) {
1389 			/*
1390 			 * Don't actually purge the chunk here because 1)
1391 			 * chunkselm is embedded in the chunk and must remain
1392 			 * valid, and 2) we deallocate the chunk in
1393 			 * arena_unstash_purged(), where it is destroyed,
1394 			 * decommitted, or purged, depending on chunk
1395 			 * deallocation policy.
1396 			 */
1397 			size_t size = extent_node_size_get(chunkselm);
1398 			npages = size >> LG_PAGE;
1399 			chunkselm = qr_next(chunkselm, cc_link);
1400 		} else {
1401 			size_t pageind, run_size, flag_unzeroed, flags, i;
1402 			bool decommitted;
1403 			arena_chunk_t *chunk =
1404 			    (arena_chunk_t *)CHUNK_ADDR2BASE(rdelm);
1405 			arena_chunk_map_misc_t *miscelm =
1406 			    arena_rd_to_miscelm(rdelm);
1407 			pageind = arena_miscelm_to_pageind(miscelm);
1408 			run_size = arena_mapbits_large_size_get(chunk, pageind);
1409 			npages = run_size >> LG_PAGE;
1410 
1411 			assert(pageind + npages <= chunk_npages);
1412 			assert(!arena_mapbits_decommitted_get(chunk, pageind));
1413 			assert(!arena_mapbits_decommitted_get(chunk,
1414 			    pageind+npages-1));
1415 			decommitted = !chunk_hooks->decommit(chunk, chunksize,
1416 			    pageind << LG_PAGE, npages << LG_PAGE, arena->ind);
1417 			if (decommitted) {
1418 				flag_unzeroed = 0;
1419 				flags = CHUNK_MAP_DECOMMITTED;
1420 			} else {
1421 				flag_unzeroed = chunk_purge_wrapper(arena,
1422 				    chunk_hooks, chunk, chunksize, pageind <<
1423 				    LG_PAGE, run_size) ? CHUNK_MAP_UNZEROED : 0;
1424 				flags = flag_unzeroed;
1425 			}
1426 			arena_mapbits_large_set(chunk, pageind+npages-1, 0,
1427 			    flags);
1428 			arena_mapbits_large_set(chunk, pageind, run_size,
1429 			    flags);
1430 
1431 			/*
1432 			 * Set the unzeroed flag for internal pages, now that
1433 			 * chunk_purge_wrapper() has returned whether the pages
1434 			 * were zeroed as a side effect of purging.  This chunk
1435 			 * map modification is safe even though the arena mutex
1436 			 * isn't currently owned by this thread, because the run
1437 			 * is marked as allocated, thus protecting it from being
1438 			 * modified by any other thread.  As long as these
1439 			 * writes don't perturb the first and last elements'
1440 			 * CHUNK_MAP_ALLOCATED bits, behavior is well defined.
1441 			 */
1442 			for (i = 1; i < npages-1; i++) {
1443 				arena_mapbits_internal_set(chunk, pageind+i,
1444 				    flag_unzeroed);
1445 			}
1446 		}
1447 
1448 		npurged += npages;
1449 		if (config_stats)
1450 			nmadvise++;
1451 	}
1452 	malloc_mutex_lock(&arena->lock);
1453 
1454 	if (config_stats) {
1455 		arena->stats.nmadvise += nmadvise;
1456 		arena->stats.purged += npurged;
1457 	}
1458 
1459 	return (npurged);
1460 }
1461 
1462 static void
1463 arena_unstash_purged(arena_t *arena, chunk_hooks_t *chunk_hooks,
1464     arena_runs_dirty_link_t *purge_runs_sentinel,
1465     extent_node_t *purge_chunks_sentinel)
1466 {
1467 	arena_runs_dirty_link_t *rdelm, *rdelm_next;
1468 	extent_node_t *chunkselm;
1469 
1470 	/* Deallocate chunks/runs. */
1471 	for (rdelm = qr_next(purge_runs_sentinel, rd_link),
1472 	    chunkselm = qr_next(purge_chunks_sentinel, cc_link);
1473 	    rdelm != purge_runs_sentinel; rdelm = rdelm_next) {
1474 		rdelm_next = qr_next(rdelm, rd_link);
1475 		if (rdelm == &chunkselm->rd) {
1476 			extent_node_t *chunkselm_next = qr_next(chunkselm,
1477 			    cc_link);
1478 			void *addr = extent_node_addr_get(chunkselm);
1479 			size_t size = extent_node_size_get(chunkselm);
1480 			bool zeroed = extent_node_zeroed_get(chunkselm);
1481 			bool committed = extent_node_committed_get(chunkselm);
1482 			extent_node_dirty_remove(chunkselm);
1483 			arena_node_dalloc(arena, chunkselm);
1484 			chunkselm = chunkselm_next;
1485 			chunk_dalloc_arena(arena, chunk_hooks, addr, size,
1486 			    zeroed, committed);
1487 		} else {
1488 			arena_chunk_t *chunk =
1489 			    (arena_chunk_t *)CHUNK_ADDR2BASE(rdelm);
1490 			arena_chunk_map_misc_t *miscelm =
1491 			    arena_rd_to_miscelm(rdelm);
1492 			size_t pageind = arena_miscelm_to_pageind(miscelm);
1493 			bool decommitted = (arena_mapbits_decommitted_get(chunk,
1494 			    pageind) != 0);
1495 			arena_run_t *run = &miscelm->run;
1496 			qr_remove(rdelm, rd_link);
1497 			arena_run_dalloc(arena, run, false, true, decommitted);
1498 		}
1499 	}
1500 }
1501 
1502 static void
1503 arena_purge(arena_t *arena, bool all)
1504 {
1505 	chunk_hooks_t chunk_hooks = chunk_hooks_get(arena);
1506 	size_t npurge, npurgeable, npurged;
1507 	arena_runs_dirty_link_t purge_runs_sentinel;
1508 	extent_node_t purge_chunks_sentinel;
1509 
1510 	arena->purging = true;
1511 
1512 	/*
1513 	 * Calls to arena_dirty_count() are disabled even for debug builds
1514 	 * because overhead grows nonlinearly as memory usage increases.
1515 	 */
1516 	if (false && config_debug) {
1517 		size_t ndirty = arena_dirty_count(arena);
1518 		assert(ndirty == arena->ndirty);
1519 	}
1520 	assert((arena->nactive >> arena->lg_dirty_mult) < arena->ndirty || all);
1521 
1522 	if (config_stats)
1523 		arena->stats.npurge++;
1524 
1525 	npurge = arena_compute_npurge(arena, all);
1526 	qr_new(&purge_runs_sentinel, rd_link);
1527 	extent_node_dirty_linkage_init(&purge_chunks_sentinel);
1528 
1529 	npurgeable = arena_stash_dirty(arena, &chunk_hooks, all, npurge,
1530 	    &purge_runs_sentinel, &purge_chunks_sentinel);
1531 	assert(npurgeable >= npurge);
1532 	npurged = arena_purge_stashed(arena, &chunk_hooks, &purge_runs_sentinel,
1533 	    &purge_chunks_sentinel);
1534 	assert(npurged == npurgeable);
1535 	arena_unstash_purged(arena, &chunk_hooks, &purge_runs_sentinel,
1536 	    &purge_chunks_sentinel);
1537 
1538 	arena->purging = false;
1539 }
1540 
1541 void
1542 arena_purge_all(arena_t *arena)
1543 {
1544 
1545 	malloc_mutex_lock(&arena->lock);
1546 	arena_purge(arena, true);
1547 	malloc_mutex_unlock(&arena->lock);
1548 }
1549 
1550 static void
1551 arena_run_coalesce(arena_t *arena, arena_chunk_t *chunk, size_t *p_size,
1552     size_t *p_run_ind, size_t *p_run_pages, size_t flag_dirty,
1553     size_t flag_decommitted)
1554 {
1555 	size_t size = *p_size;
1556 	size_t run_ind = *p_run_ind;
1557 	size_t run_pages = *p_run_pages;
1558 
1559 	/* Try to coalesce forward. */
1560 	if (run_ind + run_pages < chunk_npages &&
1561 	    arena_mapbits_allocated_get(chunk, run_ind+run_pages) == 0 &&
1562 	    arena_mapbits_dirty_get(chunk, run_ind+run_pages) == flag_dirty &&
1563 	    arena_mapbits_decommitted_get(chunk, run_ind+run_pages) ==
1564 	    flag_decommitted) {
1565 		size_t nrun_size = arena_mapbits_unallocated_size_get(chunk,
1566 		    run_ind+run_pages);
1567 		size_t nrun_pages = nrun_size >> LG_PAGE;
1568 
1569 		/*
1570 		 * Remove successor from runs_avail; the coalesced run is
1571 		 * inserted later.
1572 		 */
1573 		assert(arena_mapbits_unallocated_size_get(chunk,
1574 		    run_ind+run_pages+nrun_pages-1) == nrun_size);
1575 		assert(arena_mapbits_dirty_get(chunk,
1576 		    run_ind+run_pages+nrun_pages-1) == flag_dirty);
1577 		assert(arena_mapbits_decommitted_get(chunk,
1578 		    run_ind+run_pages+nrun_pages-1) == flag_decommitted);
1579 		arena_avail_remove(arena, chunk, run_ind+run_pages, nrun_pages);
1580 
1581 		/*
1582 		 * If the successor is dirty, remove it from the set of dirty
1583 		 * pages.
1584 		 */
1585 		if (flag_dirty != 0) {
1586 			arena_run_dirty_remove(arena, chunk, run_ind+run_pages,
1587 			    nrun_pages);
1588 		}
1589 
1590 		size += nrun_size;
1591 		run_pages += nrun_pages;
1592 
1593 		arena_mapbits_unallocated_size_set(chunk, run_ind, size);
1594 		arena_mapbits_unallocated_size_set(chunk, run_ind+run_pages-1,
1595 		    size);
1596 	}
1597 
1598 	/* Try to coalesce backward. */
1599 	if (run_ind > map_bias && arena_mapbits_allocated_get(chunk,
1600 	    run_ind-1) == 0 && arena_mapbits_dirty_get(chunk, run_ind-1) ==
1601 	    flag_dirty && arena_mapbits_decommitted_get(chunk, run_ind-1) ==
1602 	    flag_decommitted) {
1603 		size_t prun_size = arena_mapbits_unallocated_size_get(chunk,
1604 		    run_ind-1);
1605 		size_t prun_pages = prun_size >> LG_PAGE;
1606 
1607 		run_ind -= prun_pages;
1608 
1609 		/*
1610 		 * Remove predecessor from runs_avail; the coalesced run is
1611 		 * inserted later.
1612 		 */
1613 		assert(arena_mapbits_unallocated_size_get(chunk, run_ind) ==
1614 		    prun_size);
1615 		assert(arena_mapbits_dirty_get(chunk, run_ind) == flag_dirty);
1616 		assert(arena_mapbits_decommitted_get(chunk, run_ind) ==
1617 		    flag_decommitted);
1618 		arena_avail_remove(arena, chunk, run_ind, prun_pages);
1619 
1620 		/*
1621 		 * If the predecessor is dirty, remove it from the set of dirty
1622 		 * pages.
1623 		 */
1624 		if (flag_dirty != 0) {
1625 			arena_run_dirty_remove(arena, chunk, run_ind,
1626 			    prun_pages);
1627 		}
1628 
1629 		size += prun_size;
1630 		run_pages += prun_pages;
1631 
1632 		arena_mapbits_unallocated_size_set(chunk, run_ind, size);
1633 		arena_mapbits_unallocated_size_set(chunk, run_ind+run_pages-1,
1634 		    size);
1635 	}
1636 
1637 	*p_size = size;
1638 	*p_run_ind = run_ind;
1639 	*p_run_pages = run_pages;
1640 }
1641 
1642 static size_t
1643 arena_run_size_get(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
1644     size_t run_ind)
1645 {
1646 	size_t size;
1647 
1648 	assert(run_ind >= map_bias);
1649 	assert(run_ind < chunk_npages);
1650 
1651 	if (arena_mapbits_large_get(chunk, run_ind) != 0) {
1652 		size = arena_mapbits_large_size_get(chunk, run_ind);
1653 		assert(size == PAGE || arena_mapbits_large_size_get(chunk,
1654 		    run_ind+(size>>LG_PAGE)-1) == 0);
1655 	} else {
1656 		arena_bin_info_t *bin_info = &arena_bin_info[run->binind];
1657 		size = bin_info->run_size;
1658 	}
1659 
1660 	return (size);
1661 }
1662 
1663 static bool
1664 arena_run_decommit(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run)
1665 {
1666 	arena_chunk_map_misc_t *miscelm = arena_run_to_miscelm(run);
1667 	size_t run_ind = arena_miscelm_to_pageind(miscelm);
1668 	size_t offset = run_ind << LG_PAGE;
1669 	size_t length = arena_run_size_get(arena, chunk, run, run_ind);
1670 
1671 	return (arena->chunk_hooks.decommit(chunk, chunksize, offset, length,
1672 	    arena->ind));
1673 }
1674 
1675 static void
1676 arena_run_dalloc(arena_t *arena, arena_run_t *run, bool dirty, bool cleaned,
1677     bool decommitted)
1678 {
1679 	arena_chunk_t *chunk;
1680 	arena_chunk_map_misc_t *miscelm;
1681 	size_t size, run_ind, run_pages, flag_dirty, flag_decommitted;
1682 
1683 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
1684 	miscelm = arena_run_to_miscelm(run);
1685 	run_ind = arena_miscelm_to_pageind(miscelm);
1686 	assert(run_ind >= map_bias);
1687 	assert(run_ind < chunk_npages);
1688 	size = arena_run_size_get(arena, chunk, run, run_ind);
1689 	run_pages = (size >> LG_PAGE);
1690 	arena_cactive_update(arena, 0, run_pages);
1691 	arena->nactive -= run_pages;
1692 
1693 	/*
1694 	 * The run is dirty if the caller claims to have dirtied it, as well as
1695 	 * if it was already dirty before being allocated and the caller
1696 	 * doesn't claim to have cleaned it.
1697 	 */
1698 	assert(arena_mapbits_dirty_get(chunk, run_ind) ==
1699 	    arena_mapbits_dirty_get(chunk, run_ind+run_pages-1));
1700 	if (!cleaned && !decommitted && arena_mapbits_dirty_get(chunk, run_ind)
1701 	    != 0)
1702 		dirty = true;
1703 	flag_dirty = dirty ? CHUNK_MAP_DIRTY : 0;
1704 	flag_decommitted = decommitted ? CHUNK_MAP_DECOMMITTED : 0;
1705 
1706 	/* Mark pages as unallocated in the chunk map. */
1707 	if (dirty || decommitted) {
1708 		size_t flags = flag_dirty | flag_decommitted;
1709 		arena_mapbits_unallocated_set(chunk, run_ind, size, flags);
1710 		arena_mapbits_unallocated_set(chunk, run_ind+run_pages-1, size,
1711 		    flags);
1712 	} else {
1713 		arena_mapbits_unallocated_set(chunk, run_ind, size,
1714 		    arena_mapbits_unzeroed_get(chunk, run_ind));
1715 		arena_mapbits_unallocated_set(chunk, run_ind+run_pages-1, size,
1716 		    arena_mapbits_unzeroed_get(chunk, run_ind+run_pages-1));
1717 	}
1718 
1719 	arena_run_coalesce(arena, chunk, &size, &run_ind, &run_pages,
1720 	    flag_dirty, flag_decommitted);
1721 
1722 	/* Insert into runs_avail, now that coalescing is complete. */
1723 	assert(arena_mapbits_unallocated_size_get(chunk, run_ind) ==
1724 	    arena_mapbits_unallocated_size_get(chunk, run_ind+run_pages-1));
1725 	assert(arena_mapbits_dirty_get(chunk, run_ind) ==
1726 	    arena_mapbits_dirty_get(chunk, run_ind+run_pages-1));
1727 	assert(arena_mapbits_decommitted_get(chunk, run_ind) ==
1728 	    arena_mapbits_decommitted_get(chunk, run_ind+run_pages-1));
1729 	arena_avail_insert(arena, chunk, run_ind, run_pages);
1730 
1731 	if (dirty)
1732 		arena_run_dirty_insert(arena, chunk, run_ind, run_pages);
1733 
1734 	/* Deallocate chunk if it is now completely unused. */
1735 	if (size == arena_maxrun) {
1736 		assert(run_ind == map_bias);
1737 		assert(run_pages == (arena_maxrun >> LG_PAGE));
1738 		arena_chunk_dalloc(arena, chunk);
1739 	}
1740 
1741 	/*
1742 	 * It is okay to do dirty page processing here even if the chunk was
1743 	 * deallocated above, since in that case it is the spare.  Waiting
1744 	 * until after possible chunk deallocation to do dirty processing
1745 	 * allows for an old spare to be fully deallocated, thus decreasing the
1746 	 * chances of spuriously crossing the dirty page purging threshold.
1747 	 */
1748 	if (dirty)
1749 		arena_maybe_purge(arena);
1750 }
1751 
1752 static void
1753 arena_run_dalloc_decommit(arena_t *arena, arena_chunk_t *chunk,
1754     arena_run_t *run)
1755 {
1756 	bool committed = arena_run_decommit(arena, chunk, run);
1757 
1758 	arena_run_dalloc(arena, run, committed, false, !committed);
1759 }
1760 
1761 static void
1762 arena_run_trim_head(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
1763     size_t oldsize, size_t newsize)
1764 {
1765 	arena_chunk_map_misc_t *miscelm = arena_run_to_miscelm(run);
1766 	size_t pageind = arena_miscelm_to_pageind(miscelm);
1767 	size_t head_npages = (oldsize - newsize) >> LG_PAGE;
1768 	size_t flag_dirty = arena_mapbits_dirty_get(chunk, pageind);
1769 	size_t flag_decommitted = arena_mapbits_decommitted_get(chunk, pageind);
1770 	size_t flag_unzeroed_mask = (flag_dirty | flag_decommitted) == 0 ?
1771 	    CHUNK_MAP_UNZEROED : 0;
1772 
1773 	assert(oldsize > newsize);
1774 
1775 	/*
1776 	 * Update the chunk map so that arena_run_dalloc() can treat the
1777 	 * leading run as separately allocated.  Set the last element of each
1778 	 * run first, in case of single-page runs.
1779 	 */
1780 	assert(arena_mapbits_large_size_get(chunk, pageind) == oldsize);
1781 	arena_mapbits_large_set(chunk, pageind+head_npages-1, 0, flag_dirty |
1782 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
1783 	    pageind+head_npages-1)));
1784 	arena_mapbits_large_set(chunk, pageind, oldsize-newsize, flag_dirty |
1785 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk, pageind)));
1786 
1787 	if (config_debug) {
1788 		UNUSED size_t tail_npages = newsize >> LG_PAGE;
1789 		assert(arena_mapbits_large_size_get(chunk,
1790 		    pageind+head_npages+tail_npages-1) == 0);
1791 		assert(arena_mapbits_dirty_get(chunk,
1792 		    pageind+head_npages+tail_npages-1) == flag_dirty);
1793 	}
1794 	arena_mapbits_large_set(chunk, pageind+head_npages, newsize,
1795 	    flag_dirty | (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
1796 	    pageind+head_npages)));
1797 
1798 	arena_run_dalloc(arena, run, false, false, (flag_decommitted != 0));
1799 }
1800 
1801 static void
1802 arena_run_trim_tail(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
1803     size_t oldsize, size_t newsize, bool dirty)
1804 {
1805 	arena_chunk_map_misc_t *miscelm = arena_run_to_miscelm(run);
1806 	size_t pageind = arena_miscelm_to_pageind(miscelm);
1807 	size_t head_npages = newsize >> LG_PAGE;
1808 	size_t flag_dirty = arena_mapbits_dirty_get(chunk, pageind);
1809 	size_t flag_decommitted = arena_mapbits_decommitted_get(chunk, pageind);
1810 	size_t flag_unzeroed_mask = (flag_dirty | flag_decommitted) == 0 ?
1811 	    CHUNK_MAP_UNZEROED : 0;
1812 	arena_chunk_map_misc_t *tail_miscelm;
1813 	arena_run_t *tail_run;
1814 
1815 	assert(oldsize > newsize);
1816 
1817 	/*
1818 	 * Update the chunk map so that arena_run_dalloc() can treat the
1819 	 * trailing run as separately allocated.  Set the last element of each
1820 	 * run first, in case of single-page runs.
1821 	 */
1822 	assert(arena_mapbits_large_size_get(chunk, pageind) == oldsize);
1823 	arena_mapbits_large_set(chunk, pageind+head_npages-1, 0, flag_dirty |
1824 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
1825 	    pageind+head_npages-1)));
1826 	arena_mapbits_large_set(chunk, pageind, newsize, flag_dirty |
1827 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk, pageind)));
1828 
1829 	if (config_debug) {
1830 		UNUSED size_t tail_npages = (oldsize - newsize) >> LG_PAGE;
1831 		assert(arena_mapbits_large_size_get(chunk,
1832 		    pageind+head_npages+tail_npages-1) == 0);
1833 		assert(arena_mapbits_dirty_get(chunk,
1834 		    pageind+head_npages+tail_npages-1) == flag_dirty);
1835 	}
1836 	arena_mapbits_large_set(chunk, pageind+head_npages, oldsize-newsize,
1837 	    flag_dirty | (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
1838 	    pageind+head_npages)));
1839 
1840 	tail_miscelm = arena_miscelm_get(chunk, pageind + head_npages);
1841 	tail_run = &tail_miscelm->run;
1842 	arena_run_dalloc(arena, tail_run, dirty, false, (flag_decommitted !=
1843 	    0));
1844 }
1845 
1846 static arena_run_t *
1847 arena_bin_runs_first(arena_bin_t *bin)
1848 {
1849 	arena_chunk_map_misc_t *miscelm = arena_run_tree_first(&bin->runs);
1850 	if (miscelm != NULL)
1851 		return (&miscelm->run);
1852 
1853 	return (NULL);
1854 }
1855 
1856 static void
1857 arena_bin_runs_insert(arena_bin_t *bin, arena_run_t *run)
1858 {
1859 	arena_chunk_map_misc_t *miscelm = arena_run_to_miscelm(run);
1860 
1861 	assert(arena_run_tree_search(&bin->runs, miscelm) == NULL);
1862 
1863 	arena_run_tree_insert(&bin->runs, miscelm);
1864 }
1865 
1866 static void
1867 arena_bin_runs_remove(arena_bin_t *bin, arena_run_t *run)
1868 {
1869 	arena_chunk_map_misc_t *miscelm = arena_run_to_miscelm(run);
1870 
1871 	assert(arena_run_tree_search(&bin->runs, miscelm) != NULL);
1872 
1873 	arena_run_tree_remove(&bin->runs, miscelm);
1874 }
1875 
1876 static arena_run_t *
1877 arena_bin_nonfull_run_tryget(arena_bin_t *bin)
1878 {
1879 	arena_run_t *run = arena_bin_runs_first(bin);
1880 	if (run != NULL) {
1881 		arena_bin_runs_remove(bin, run);
1882 		if (config_stats)
1883 			bin->stats.reruns++;
1884 	}
1885 	return (run);
1886 }
1887 
1888 static arena_run_t *
1889 arena_bin_nonfull_run_get(arena_t *arena, arena_bin_t *bin)
1890 {
1891 	arena_run_t *run;
1892 	szind_t binind;
1893 	arena_bin_info_t *bin_info;
1894 
1895 	/* Look for a usable run. */
1896 	run = arena_bin_nonfull_run_tryget(bin);
1897 	if (run != NULL)
1898 		return (run);
1899 	/* No existing runs have any space available. */
1900 
1901 	binind = arena_bin_index(arena, bin);
1902 	bin_info = &arena_bin_info[binind];
1903 
1904 	/* Allocate a new run. */
1905 	malloc_mutex_unlock(&bin->lock);
1906 	/******************************/
1907 	malloc_mutex_lock(&arena->lock);
1908 	run = arena_run_alloc_small(arena, bin_info->run_size, binind);
1909 	if (run != NULL) {
1910 		/* Initialize run internals. */
1911 		run->binind = binind;
1912 		run->nfree = bin_info->nregs;
1913 		bitmap_init(run->bitmap, &bin_info->bitmap_info);
1914 	}
1915 	malloc_mutex_unlock(&arena->lock);
1916 	/********************************/
1917 	malloc_mutex_lock(&bin->lock);
1918 	if (run != NULL) {
1919 		if (config_stats) {
1920 			bin->stats.nruns++;
1921 			bin->stats.curruns++;
1922 		}
1923 		return (run);
1924 	}
1925 
1926 	/*
1927 	 * arena_run_alloc_small() failed, but another thread may have made
1928 	 * sufficient memory available while this one dropped bin->lock above,
1929 	 * so search one more time.
1930 	 */
1931 	run = arena_bin_nonfull_run_tryget(bin);
1932 	if (run != NULL)
1933 		return (run);
1934 
1935 	return (NULL);
1936 }
1937 
1938 /* Re-fill bin->runcur, then call arena_run_reg_alloc(). */
1939 static void *
1940 arena_bin_malloc_hard(arena_t *arena, arena_bin_t *bin)
1941 {
1942 	szind_t binind;
1943 	arena_bin_info_t *bin_info;
1944 	arena_run_t *run;
1945 
1946 	binind = arena_bin_index(arena, bin);
1947 	bin_info = &arena_bin_info[binind];
1948 	bin->runcur = NULL;
1949 	run = arena_bin_nonfull_run_get(arena, bin);
1950 	if (bin->runcur != NULL && bin->runcur->nfree > 0) {
1951 		/*
1952 		 * Another thread updated runcur while this one ran without the
1953 		 * bin lock in arena_bin_nonfull_run_get().
1954 		 */
1955 		void *ret;
1956 		assert(bin->runcur->nfree > 0);
1957 		ret = arena_run_reg_alloc(bin->runcur, bin_info);
1958 		if (run != NULL) {
1959 			arena_chunk_t *chunk;
1960 
1961 			/*
1962 			 * arena_run_alloc_small() may have allocated run, or
1963 			 * it may have pulled run from the bin's run tree.
1964 			 * Therefore it is unsafe to make any assumptions about
1965 			 * how run has previously been used, and
1966 			 * arena_bin_lower_run() must be called, as if a region
1967 			 * were just deallocated from the run.
1968 			 */
1969 			chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
1970 			if (run->nfree == bin_info->nregs)
1971 				arena_dalloc_bin_run(arena, chunk, run, bin);
1972 			else
1973 				arena_bin_lower_run(arena, chunk, run, bin);
1974 		}
1975 		return (ret);
1976 	}
1977 
1978 	if (run == NULL)
1979 		return (NULL);
1980 
1981 	bin->runcur = run;
1982 
1983 	assert(bin->runcur->nfree > 0);
1984 
1985 	return (arena_run_reg_alloc(bin->runcur, bin_info));
1986 }
1987 
1988 void
1989 arena_tcache_fill_small(arena_t *arena, tcache_bin_t *tbin, szind_t binind,
1990     uint64_t prof_accumbytes)
1991 {
1992 	unsigned i, nfill;
1993 	arena_bin_t *bin;
1994 
1995 	assert(tbin->ncached == 0);
1996 
1997 	if (config_prof && arena_prof_accum(arena, prof_accumbytes))
1998 		prof_idump();
1999 	bin = &arena->bins[binind];
2000 	malloc_mutex_lock(&bin->lock);
2001 	for (i = 0, nfill = (tcache_bin_info[binind].ncached_max >>
2002 	    tbin->lg_fill_div); i < nfill; i++) {
2003 		arena_run_t *run;
2004 		void *ptr;
2005 		if ((run = bin->runcur) != NULL && run->nfree > 0)
2006 			ptr = arena_run_reg_alloc(run, &arena_bin_info[binind]);
2007 		else
2008 			ptr = arena_bin_malloc_hard(arena, bin);
2009 		if (ptr == NULL) {
2010 			/*
2011 			 * OOM.  tbin->avail isn't yet filled down to its first
2012 			 * element, so the successful allocations (if any) must
2013 			 * be moved to the base of tbin->avail before bailing
2014 			 * out.
2015 			 */
2016 			if (i > 0) {
2017 				memmove(tbin->avail, &tbin->avail[nfill - i],
2018 				    i * sizeof(void *));
2019 			}
2020 			break;
2021 		}
2022 		if (config_fill && unlikely(opt_junk_alloc)) {
2023 			arena_alloc_junk_small(ptr, &arena_bin_info[binind],
2024 			    true);
2025 		}
2026 		/* Insert such that low regions get used first. */
2027 		tbin->avail[nfill - 1 - i] = ptr;
2028 	}
2029 	if (config_stats) {
2030 		bin->stats.nmalloc += i;
2031 		bin->stats.nrequests += tbin->tstats.nrequests;
2032 		bin->stats.curregs += i;
2033 		bin->stats.nfills++;
2034 		tbin->tstats.nrequests = 0;
2035 	}
2036 	malloc_mutex_unlock(&bin->lock);
2037 	tbin->ncached = i;
2038 }
2039 
2040 void
2041 arena_alloc_junk_small(void *ptr, arena_bin_info_t *bin_info, bool zero)
2042 {
2043 
2044 	if (zero) {
2045 		size_t redzone_size = bin_info->redzone_size;
2046 		memset((void *)((uintptr_t)ptr - redzone_size), 0xa5,
2047 		    redzone_size);
2048 		memset((void *)((uintptr_t)ptr + bin_info->reg_size), 0xa5,
2049 		    redzone_size);
2050 	} else {
2051 		memset((void *)((uintptr_t)ptr - bin_info->redzone_size), 0xa5,
2052 		    bin_info->reg_interval);
2053 	}
2054 }
2055 
2056 #ifdef JEMALLOC_JET
2057 #undef arena_redzone_corruption
2058 #define	arena_redzone_corruption JEMALLOC_N(arena_redzone_corruption_impl)
2059 #endif
2060 static void
2061 arena_redzone_corruption(void *ptr, size_t usize, bool after,
2062     size_t offset, uint8_t byte)
2063 {
2064 
2065 	malloc_printf("<jemalloc>: Corrupt redzone %zu byte%s %s %p "
2066 	    "(size %zu), byte=%#x\n", offset, (offset == 1) ? "" : "s",
2067 	    after ? "after" : "before", ptr, usize, byte);
2068 }
2069 #ifdef JEMALLOC_JET
2070 #undef arena_redzone_corruption
2071 #define	arena_redzone_corruption JEMALLOC_N(arena_redzone_corruption)
2072 arena_redzone_corruption_t *arena_redzone_corruption =
2073     JEMALLOC_N(arena_redzone_corruption_impl);
2074 #endif
2075 
2076 static void
2077 arena_redzones_validate(void *ptr, arena_bin_info_t *bin_info, bool reset)
2078 {
2079 	bool error = false;
2080 
2081 	if (opt_junk_alloc) {
2082 		size_t size = bin_info->reg_size;
2083 		size_t redzone_size = bin_info->redzone_size;
2084 		size_t i;
2085 
2086 		for (i = 1; i <= redzone_size; i++) {
2087 			uint8_t *byte = (uint8_t *)((uintptr_t)ptr - i);
2088 			if (*byte != 0xa5) {
2089 				error = true;
2090 				arena_redzone_corruption(ptr, size, false, i,
2091 				    *byte);
2092 				if (reset)
2093 					*byte = 0xa5;
2094 			}
2095 		}
2096 		for (i = 0; i < redzone_size; i++) {
2097 			uint8_t *byte = (uint8_t *)((uintptr_t)ptr + size + i);
2098 			if (*byte != 0xa5) {
2099 				error = true;
2100 				arena_redzone_corruption(ptr, size, true, i,
2101 				    *byte);
2102 				if (reset)
2103 					*byte = 0xa5;
2104 			}
2105 		}
2106 	}
2107 
2108 	if (opt_abort && error)
2109 		abort();
2110 }
2111 
2112 #ifdef JEMALLOC_JET
2113 #undef arena_dalloc_junk_small
2114 #define	arena_dalloc_junk_small JEMALLOC_N(arena_dalloc_junk_small_impl)
2115 #endif
2116 void
2117 arena_dalloc_junk_small(void *ptr, arena_bin_info_t *bin_info)
2118 {
2119 	size_t redzone_size = bin_info->redzone_size;
2120 
2121 	arena_redzones_validate(ptr, bin_info, false);
2122 	memset((void *)((uintptr_t)ptr - redzone_size), 0x5a,
2123 	    bin_info->reg_interval);
2124 }
2125 #ifdef JEMALLOC_JET
2126 #undef arena_dalloc_junk_small
2127 #define	arena_dalloc_junk_small JEMALLOC_N(arena_dalloc_junk_small)
2128 arena_dalloc_junk_small_t *arena_dalloc_junk_small =
2129     JEMALLOC_N(arena_dalloc_junk_small_impl);
2130 #endif
2131 
2132 void
2133 arena_quarantine_junk_small(void *ptr, size_t usize)
2134 {
2135 	szind_t binind;
2136 	arena_bin_info_t *bin_info;
2137 	cassert(config_fill);
2138 	assert(opt_junk_free);
2139 	assert(opt_quarantine);
2140 	assert(usize <= SMALL_MAXCLASS);
2141 
2142 	binind = size2index(usize);
2143 	bin_info = &arena_bin_info[binind];
2144 	arena_redzones_validate(ptr, bin_info, true);
2145 }
2146 
2147 void *
2148 arena_malloc_small(arena_t *arena, size_t size, bool zero)
2149 {
2150 	void *ret;
2151 	arena_bin_t *bin;
2152 	arena_run_t *run;
2153 	szind_t binind;
2154 
2155 	binind = size2index(size);
2156 	assert(binind < NBINS);
2157 	bin = &arena->bins[binind];
2158 	size = index2size(binind);
2159 
2160 	malloc_mutex_lock(&bin->lock);
2161 	if ((run = bin->runcur) != NULL && run->nfree > 0)
2162 		ret = arena_run_reg_alloc(run, &arena_bin_info[binind]);
2163 	else
2164 		ret = arena_bin_malloc_hard(arena, bin);
2165 
2166 	if (ret == NULL) {
2167 		malloc_mutex_unlock(&bin->lock);
2168 		return (NULL);
2169 	}
2170 
2171 	if (config_stats) {
2172 		bin->stats.nmalloc++;
2173 		bin->stats.nrequests++;
2174 		bin->stats.curregs++;
2175 	}
2176 	malloc_mutex_unlock(&bin->lock);
2177 	if (config_prof && !isthreaded && arena_prof_accum(arena, size))
2178 		prof_idump();
2179 
2180 	if (!zero) {
2181 		if (config_fill) {
2182 			if (unlikely(opt_junk_alloc)) {
2183 				arena_alloc_junk_small(ret,
2184 				    &arena_bin_info[binind], false);
2185 			} else if (unlikely(opt_zero))
2186 				memset(ret, 0, size);
2187 		}
2188 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size);
2189 	} else {
2190 		if (config_fill && unlikely(opt_junk_alloc)) {
2191 			arena_alloc_junk_small(ret, &arena_bin_info[binind],
2192 			    true);
2193 		}
2194 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size);
2195 		memset(ret, 0, size);
2196 	}
2197 
2198 	return (ret);
2199 }
2200 
2201 void *
2202 arena_malloc_large(arena_t *arena, size_t size, bool zero)
2203 {
2204 	void *ret;
2205 	size_t usize;
2206 	uintptr_t random_offset;
2207 	arena_run_t *run;
2208 	arena_chunk_map_misc_t *miscelm;
2209 	UNUSED bool idump;
2210 
2211 	/* Large allocation. */
2212 	usize = s2u(size);
2213 	malloc_mutex_lock(&arena->lock);
2214 	if (config_cache_oblivious) {
2215 		uint64_t r;
2216 
2217 		/*
2218 		 * Compute a uniformly distributed offset within the first page
2219 		 * that is a multiple of the cacheline size, e.g. [0 .. 63) * 64
2220 		 * for 4 KiB pages and 64-byte cachelines.
2221 		 */
2222 		prng64(r, LG_PAGE - LG_CACHELINE, arena->offset_state,
2223 		    UINT64_C(6364136223846793009),
2224 		    UINT64_C(1442695040888963409));
2225 		random_offset = ((uintptr_t)r) << LG_CACHELINE;
2226 	} else
2227 		random_offset = 0;
2228 	run = arena_run_alloc_large(arena, usize + large_pad, zero);
2229 	if (run == NULL) {
2230 		malloc_mutex_unlock(&arena->lock);
2231 		return (NULL);
2232 	}
2233 	miscelm = arena_run_to_miscelm(run);
2234 	ret = (void *)((uintptr_t)arena_miscelm_to_rpages(miscelm) +
2235 	    random_offset);
2236 	if (config_stats) {
2237 		szind_t index = size2index(usize) - NBINS;
2238 
2239 		arena->stats.nmalloc_large++;
2240 		arena->stats.nrequests_large++;
2241 		arena->stats.allocated_large += usize;
2242 		arena->stats.lstats[index].nmalloc++;
2243 		arena->stats.lstats[index].nrequests++;
2244 		arena->stats.lstats[index].curruns++;
2245 	}
2246 	if (config_prof)
2247 		idump = arena_prof_accum_locked(arena, usize);
2248 	malloc_mutex_unlock(&arena->lock);
2249 	if (config_prof && idump)
2250 		prof_idump();
2251 
2252 	if (!zero) {
2253 		if (config_fill) {
2254 			if (unlikely(opt_junk_alloc))
2255 				memset(ret, 0xa5, usize);
2256 			else if (unlikely(opt_zero))
2257 				memset(ret, 0, usize);
2258 		}
2259 	}
2260 
2261 	return (ret);
2262 }
2263 
2264 /* Only handles large allocations that require more than page alignment. */
2265 static void *
2266 arena_palloc_large(tsd_t *tsd, arena_t *arena, size_t usize, size_t alignment,
2267     bool zero)
2268 {
2269 	void *ret;
2270 	size_t alloc_size, leadsize, trailsize;
2271 	arena_run_t *run;
2272 	arena_chunk_t *chunk;
2273 	arena_chunk_map_misc_t *miscelm;
2274 	void *rpages;
2275 
2276 	assert(usize == PAGE_CEILING(usize));
2277 
2278 	arena = arena_choose(tsd, arena);
2279 	if (unlikely(arena == NULL))
2280 		return (NULL);
2281 
2282 	alignment = PAGE_CEILING(alignment);
2283 	alloc_size = usize + large_pad + alignment - PAGE;
2284 
2285 	malloc_mutex_lock(&arena->lock);
2286 	run = arena_run_alloc_large(arena, alloc_size, false);
2287 	if (run == NULL) {
2288 		malloc_mutex_unlock(&arena->lock);
2289 		return (NULL);
2290 	}
2291 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
2292 	miscelm = arena_run_to_miscelm(run);
2293 	rpages = arena_miscelm_to_rpages(miscelm);
2294 
2295 	leadsize = ALIGNMENT_CEILING((uintptr_t)rpages, alignment) -
2296 	    (uintptr_t)rpages;
2297 	assert(alloc_size >= leadsize + usize);
2298 	trailsize = alloc_size - leadsize - usize - large_pad;
2299 	if (leadsize != 0) {
2300 		arena_chunk_map_misc_t *head_miscelm = miscelm;
2301 		arena_run_t *head_run = run;
2302 
2303 		miscelm = arena_miscelm_get(chunk,
2304 		    arena_miscelm_to_pageind(head_miscelm) + (leadsize >>
2305 		    LG_PAGE));
2306 		run = &miscelm->run;
2307 
2308 		arena_run_trim_head(arena, chunk, head_run, alloc_size,
2309 		    alloc_size - leadsize);
2310 	}
2311 	if (trailsize != 0) {
2312 		arena_run_trim_tail(arena, chunk, run, usize + large_pad +
2313 		    trailsize, usize + large_pad, false);
2314 	}
2315 	if (arena_run_init_large(arena, run, usize + large_pad, zero)) {
2316 		size_t run_ind =
2317 		    arena_miscelm_to_pageind(arena_run_to_miscelm(run));
2318 		bool dirty = (arena_mapbits_dirty_get(chunk, run_ind) != 0);
2319 		bool decommitted = (arena_mapbits_decommitted_get(chunk,
2320 		    run_ind) != 0);
2321 
2322 		assert(decommitted); /* Cause of OOM. */
2323 		arena_run_dalloc(arena, run, dirty, false, decommitted);
2324 		malloc_mutex_unlock(&arena->lock);
2325 		return (NULL);
2326 	}
2327 	ret = arena_miscelm_to_rpages(miscelm);
2328 
2329 	if (config_stats) {
2330 		szind_t index = size2index(usize) - NBINS;
2331 
2332 		arena->stats.nmalloc_large++;
2333 		arena->stats.nrequests_large++;
2334 		arena->stats.allocated_large += usize;
2335 		arena->stats.lstats[index].nmalloc++;
2336 		arena->stats.lstats[index].nrequests++;
2337 		arena->stats.lstats[index].curruns++;
2338 	}
2339 	malloc_mutex_unlock(&arena->lock);
2340 
2341 	if (config_fill && !zero) {
2342 		if (unlikely(opt_junk_alloc))
2343 			memset(ret, 0xa5, usize);
2344 		else if (unlikely(opt_zero))
2345 			memset(ret, 0, usize);
2346 	}
2347 	return (ret);
2348 }
2349 
2350 void *
2351 arena_palloc(tsd_t *tsd, arena_t *arena, size_t usize, size_t alignment,
2352     bool zero, tcache_t *tcache)
2353 {
2354 	void *ret;
2355 
2356 	if (usize <= SMALL_MAXCLASS && (alignment < PAGE || (alignment == PAGE
2357 	    && (usize & PAGE_MASK) == 0))) {
2358 		/* Small; alignment doesn't require special run placement. */
2359 		ret = arena_malloc(tsd, arena, usize, zero, tcache);
2360 	} else if (usize <= large_maxclass && alignment <= PAGE) {
2361 		/*
2362 		 * Large; alignment doesn't require special run placement.
2363 		 * However, the cached pointer may be at a random offset from
2364 		 * the base of the run, so do some bit manipulation to retrieve
2365 		 * the base.
2366 		 */
2367 		ret = arena_malloc(tsd, arena, usize, zero, tcache);
2368 		if (config_cache_oblivious)
2369 			ret = (void *)((uintptr_t)ret & ~PAGE_MASK);
2370 	} else {
2371 		if (likely(usize <= large_maxclass)) {
2372 			ret = arena_palloc_large(tsd, arena, usize, alignment,
2373 			    zero);
2374 		} else if (likely(alignment <= chunksize))
2375 			ret = huge_malloc(tsd, arena, usize, zero, tcache);
2376 		else {
2377 			ret = huge_palloc(tsd, arena, usize, alignment, zero,
2378 			    tcache);
2379 		}
2380 	}
2381 	return (ret);
2382 }
2383 
2384 void
2385 arena_prof_promoted(const void *ptr, size_t size)
2386 {
2387 	arena_chunk_t *chunk;
2388 	size_t pageind;
2389 	szind_t binind;
2390 
2391 	cassert(config_prof);
2392 	assert(ptr != NULL);
2393 	assert(CHUNK_ADDR2BASE(ptr) != ptr);
2394 	assert(isalloc(ptr, false) == LARGE_MINCLASS);
2395 	assert(isalloc(ptr, true) == LARGE_MINCLASS);
2396 	assert(size <= SMALL_MAXCLASS);
2397 
2398 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr);
2399 	pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2400 	binind = size2index(size);
2401 	assert(binind < NBINS);
2402 	arena_mapbits_large_binind_set(chunk, pageind, binind);
2403 
2404 	assert(isalloc(ptr, false) == LARGE_MINCLASS);
2405 	assert(isalloc(ptr, true) == size);
2406 }
2407 
2408 static void
2409 arena_dissociate_bin_run(arena_chunk_t *chunk, arena_run_t *run,
2410     arena_bin_t *bin)
2411 {
2412 
2413 	/* Dissociate run from bin. */
2414 	if (run == bin->runcur)
2415 		bin->runcur = NULL;
2416 	else {
2417 		szind_t binind = arena_bin_index(extent_node_arena_get(
2418 		    &chunk->node), bin);
2419 		arena_bin_info_t *bin_info = &arena_bin_info[binind];
2420 
2421 		if (bin_info->nregs != 1) {
2422 			/*
2423 			 * This block's conditional is necessary because if the
2424 			 * run only contains one region, then it never gets
2425 			 * inserted into the non-full runs tree.
2426 			 */
2427 			arena_bin_runs_remove(bin, run);
2428 		}
2429 	}
2430 }
2431 
2432 static void
2433 arena_dalloc_bin_run(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
2434     arena_bin_t *bin)
2435 {
2436 
2437 	assert(run != bin->runcur);
2438 	assert(arena_run_tree_search(&bin->runs, arena_run_to_miscelm(run)) ==
2439 	    NULL);
2440 
2441 	malloc_mutex_unlock(&bin->lock);
2442 	/******************************/
2443 	malloc_mutex_lock(&arena->lock);
2444 	arena_run_dalloc_decommit(arena, chunk, run);
2445 	malloc_mutex_unlock(&arena->lock);
2446 	/****************************/
2447 	malloc_mutex_lock(&bin->lock);
2448 	if (config_stats)
2449 		bin->stats.curruns--;
2450 }
2451 
2452 static void
2453 arena_bin_lower_run(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
2454     arena_bin_t *bin)
2455 {
2456 
2457 	/*
2458 	 * Make sure that if bin->runcur is non-NULL, it refers to the lowest
2459 	 * non-full run.  It is okay to NULL runcur out rather than proactively
2460 	 * keeping it pointing at the lowest non-full run.
2461 	 */
2462 	if ((uintptr_t)run < (uintptr_t)bin->runcur) {
2463 		/* Switch runcur. */
2464 		if (bin->runcur->nfree > 0)
2465 			arena_bin_runs_insert(bin, bin->runcur);
2466 		bin->runcur = run;
2467 		if (config_stats)
2468 			bin->stats.reruns++;
2469 	} else
2470 		arena_bin_runs_insert(bin, run);
2471 }
2472 
2473 static void
2474 arena_dalloc_bin_locked_impl(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2475     arena_chunk_map_bits_t *bitselm, bool junked)
2476 {
2477 	size_t pageind, rpages_ind;
2478 	arena_run_t *run;
2479 	arena_bin_t *bin;
2480 	arena_bin_info_t *bin_info;
2481 	szind_t binind;
2482 
2483 	pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2484 	rpages_ind = pageind - arena_mapbits_small_runind_get(chunk, pageind);
2485 	run = &arena_miscelm_get(chunk, rpages_ind)->run;
2486 	binind = run->binind;
2487 	bin = &arena->bins[binind];
2488 	bin_info = &arena_bin_info[binind];
2489 
2490 	if (!junked && config_fill && unlikely(opt_junk_free))
2491 		arena_dalloc_junk_small(ptr, bin_info);
2492 
2493 	arena_run_reg_dalloc(run, ptr);
2494 	if (run->nfree == bin_info->nregs) {
2495 		arena_dissociate_bin_run(chunk, run, bin);
2496 		arena_dalloc_bin_run(arena, chunk, run, bin);
2497 	} else if (run->nfree == 1 && run != bin->runcur)
2498 		arena_bin_lower_run(arena, chunk, run, bin);
2499 
2500 	if (config_stats) {
2501 		bin->stats.ndalloc++;
2502 		bin->stats.curregs--;
2503 	}
2504 }
2505 
2506 void
2507 arena_dalloc_bin_junked_locked(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2508     arena_chunk_map_bits_t *bitselm)
2509 {
2510 
2511 	arena_dalloc_bin_locked_impl(arena, chunk, ptr, bitselm, true);
2512 }
2513 
2514 void
2515 arena_dalloc_bin(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2516     size_t pageind, arena_chunk_map_bits_t *bitselm)
2517 {
2518 	arena_run_t *run;
2519 	arena_bin_t *bin;
2520 	size_t rpages_ind;
2521 
2522 	rpages_ind = pageind - arena_mapbits_small_runind_get(chunk, pageind);
2523 	run = &arena_miscelm_get(chunk, rpages_ind)->run;
2524 	bin = &arena->bins[run->binind];
2525 	malloc_mutex_lock(&bin->lock);
2526 	arena_dalloc_bin_locked_impl(arena, chunk, ptr, bitselm, false);
2527 	malloc_mutex_unlock(&bin->lock);
2528 }
2529 
2530 void
2531 arena_dalloc_small(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2532     size_t pageind)
2533 {
2534 	arena_chunk_map_bits_t *bitselm;
2535 
2536 	if (config_debug) {
2537 		/* arena_ptr_small_binind_get() does extra sanity checking. */
2538 		assert(arena_ptr_small_binind_get(ptr, arena_mapbits_get(chunk,
2539 		    pageind)) != BININD_INVALID);
2540 	}
2541 	bitselm = arena_bitselm_get(chunk, pageind);
2542 	arena_dalloc_bin(arena, chunk, ptr, pageind, bitselm);
2543 }
2544 
2545 #ifdef JEMALLOC_JET
2546 #undef arena_dalloc_junk_large
2547 #define	arena_dalloc_junk_large JEMALLOC_N(arena_dalloc_junk_large_impl)
2548 #endif
2549 void
2550 arena_dalloc_junk_large(void *ptr, size_t usize)
2551 {
2552 
2553 	if (config_fill && unlikely(opt_junk_free))
2554 		memset(ptr, 0x5a, usize);
2555 }
2556 #ifdef JEMALLOC_JET
2557 #undef arena_dalloc_junk_large
2558 #define	arena_dalloc_junk_large JEMALLOC_N(arena_dalloc_junk_large)
2559 arena_dalloc_junk_large_t *arena_dalloc_junk_large =
2560     JEMALLOC_N(arena_dalloc_junk_large_impl);
2561 #endif
2562 
2563 static void
2564 arena_dalloc_large_locked_impl(arena_t *arena, arena_chunk_t *chunk,
2565     void *ptr, bool junked)
2566 {
2567 	size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2568 	arena_chunk_map_misc_t *miscelm = arena_miscelm_get(chunk, pageind);
2569 	arena_run_t *run = &miscelm->run;
2570 
2571 	if (config_fill || config_stats) {
2572 		size_t usize = arena_mapbits_large_size_get(chunk, pageind) -
2573 		    large_pad;
2574 
2575 		if (!junked)
2576 			arena_dalloc_junk_large(ptr, usize);
2577 		if (config_stats) {
2578 			szind_t index = size2index(usize) - NBINS;
2579 
2580 			arena->stats.ndalloc_large++;
2581 			arena->stats.allocated_large -= usize;
2582 			arena->stats.lstats[index].ndalloc++;
2583 			arena->stats.lstats[index].curruns--;
2584 		}
2585 	}
2586 
2587 	arena_run_dalloc_decommit(arena, chunk, run);
2588 }
2589 
2590 void
2591 arena_dalloc_large_junked_locked(arena_t *arena, arena_chunk_t *chunk,
2592     void *ptr)
2593 {
2594 
2595 	arena_dalloc_large_locked_impl(arena, chunk, ptr, true);
2596 }
2597 
2598 void
2599 arena_dalloc_large(arena_t *arena, arena_chunk_t *chunk, void *ptr)
2600 {
2601 
2602 	malloc_mutex_lock(&arena->lock);
2603 	arena_dalloc_large_locked_impl(arena, chunk, ptr, false);
2604 	malloc_mutex_unlock(&arena->lock);
2605 }
2606 
2607 static void
2608 arena_ralloc_large_shrink(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2609     size_t oldsize, size_t size)
2610 {
2611 	size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2612 	arena_chunk_map_misc_t *miscelm = arena_miscelm_get(chunk, pageind);
2613 	arena_run_t *run = &miscelm->run;
2614 
2615 	assert(size < oldsize);
2616 
2617 	/*
2618 	 * Shrink the run, and make trailing pages available for other
2619 	 * allocations.
2620 	 */
2621 	malloc_mutex_lock(&arena->lock);
2622 	arena_run_trim_tail(arena, chunk, run, oldsize + large_pad, size +
2623 	    large_pad, true);
2624 	if (config_stats) {
2625 		szind_t oldindex = size2index(oldsize) - NBINS;
2626 		szind_t index = size2index(size) - NBINS;
2627 
2628 		arena->stats.ndalloc_large++;
2629 		arena->stats.allocated_large -= oldsize;
2630 		arena->stats.lstats[oldindex].ndalloc++;
2631 		arena->stats.lstats[oldindex].curruns--;
2632 
2633 		arena->stats.nmalloc_large++;
2634 		arena->stats.nrequests_large++;
2635 		arena->stats.allocated_large += size;
2636 		arena->stats.lstats[index].nmalloc++;
2637 		arena->stats.lstats[index].nrequests++;
2638 		arena->stats.lstats[index].curruns++;
2639 	}
2640 	malloc_mutex_unlock(&arena->lock);
2641 }
2642 
2643 static bool
2644 arena_ralloc_large_grow(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2645     size_t oldsize, size_t usize_min, size_t usize_max, bool zero)
2646 {
2647 	size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2648 	size_t npages = (oldsize + large_pad) >> LG_PAGE;
2649 	size_t followsize;
2650 
2651 	assert(oldsize == arena_mapbits_large_size_get(chunk, pageind) -
2652 	    large_pad);
2653 
2654 	/* Try to extend the run. */
2655 	malloc_mutex_lock(&arena->lock);
2656 	if (pageind+npages >= chunk_npages || arena_mapbits_allocated_get(chunk,
2657 	    pageind+npages) != 0)
2658 		goto label_fail;
2659 	followsize = arena_mapbits_unallocated_size_get(chunk, pageind+npages);
2660 	if (oldsize + followsize >= usize_min) {
2661 		/*
2662 		 * The next run is available and sufficiently large.  Split the
2663 		 * following run, then merge the first part with the existing
2664 		 * allocation.
2665 		 */
2666 		arena_run_t *run;
2667 		size_t usize, splitsize, size, flag_dirty, flag_unzeroed_mask;
2668 
2669 		usize = usize_max;
2670 		while (oldsize + followsize < usize)
2671 			usize = index2size(size2index(usize)-1);
2672 		assert(usize >= usize_min);
2673 		assert(usize >= oldsize);
2674 		splitsize = usize - oldsize;
2675 		if (splitsize == 0)
2676 			goto label_fail;
2677 
2678 		run = &arena_miscelm_get(chunk, pageind+npages)->run;
2679 		if (arena_run_split_large(arena, run, splitsize, zero))
2680 			goto label_fail;
2681 
2682 		size = oldsize + splitsize;
2683 		npages = (size + large_pad) >> LG_PAGE;
2684 
2685 		/*
2686 		 * Mark the extended run as dirty if either portion of the run
2687 		 * was dirty before allocation.  This is rather pedantic,
2688 		 * because there's not actually any sequence of events that
2689 		 * could cause the resulting run to be passed to
2690 		 * arena_run_dalloc() with the dirty argument set to false
2691 		 * (which is when dirty flag consistency would really matter).
2692 		 */
2693 		flag_dirty = arena_mapbits_dirty_get(chunk, pageind) |
2694 		    arena_mapbits_dirty_get(chunk, pageind+npages-1);
2695 		flag_unzeroed_mask = flag_dirty == 0 ? CHUNK_MAP_UNZEROED : 0;
2696 		arena_mapbits_large_set(chunk, pageind, size + large_pad,
2697 		    flag_dirty | (flag_unzeroed_mask &
2698 		    arena_mapbits_unzeroed_get(chunk, pageind)));
2699 		arena_mapbits_large_set(chunk, pageind+npages-1, 0, flag_dirty |
2700 		    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
2701 		    pageind+npages-1)));
2702 
2703 		if (config_stats) {
2704 			szind_t oldindex = size2index(oldsize) - NBINS;
2705 			szind_t index = size2index(size) - NBINS;
2706 
2707 			arena->stats.ndalloc_large++;
2708 			arena->stats.allocated_large -= oldsize;
2709 			arena->stats.lstats[oldindex].ndalloc++;
2710 			arena->stats.lstats[oldindex].curruns--;
2711 
2712 			arena->stats.nmalloc_large++;
2713 			arena->stats.nrequests_large++;
2714 			arena->stats.allocated_large += size;
2715 			arena->stats.lstats[index].nmalloc++;
2716 			arena->stats.lstats[index].nrequests++;
2717 			arena->stats.lstats[index].curruns++;
2718 		}
2719 		malloc_mutex_unlock(&arena->lock);
2720 		return (false);
2721 	}
2722 label_fail:
2723 	malloc_mutex_unlock(&arena->lock);
2724 	return (true);
2725 }
2726 
2727 #ifdef JEMALLOC_JET
2728 #undef arena_ralloc_junk_large
2729 #define	arena_ralloc_junk_large JEMALLOC_N(arena_ralloc_junk_large_impl)
2730 #endif
2731 static void
2732 arena_ralloc_junk_large(void *ptr, size_t old_usize, size_t usize)
2733 {
2734 
2735 	if (config_fill && unlikely(opt_junk_free)) {
2736 		memset((void *)((uintptr_t)ptr + usize), 0x5a,
2737 		    old_usize - usize);
2738 	}
2739 }
2740 #ifdef JEMALLOC_JET
2741 #undef arena_ralloc_junk_large
2742 #define	arena_ralloc_junk_large JEMALLOC_N(arena_ralloc_junk_large)
2743 arena_ralloc_junk_large_t *arena_ralloc_junk_large =
2744     JEMALLOC_N(arena_ralloc_junk_large_impl);
2745 #endif
2746 
2747 /*
2748  * Try to resize a large allocation, in order to avoid copying.  This will
2749  * always fail if growing an object, and the following run is already in use.
2750  */
2751 static bool
2752 arena_ralloc_large(void *ptr, size_t oldsize, size_t usize_min,
2753     size_t usize_max, bool zero)
2754 {
2755 	arena_chunk_t *chunk;
2756 	arena_t *arena;
2757 
2758 	if (oldsize == usize_max) {
2759 		/* Current size class is compatible and maximal. */
2760 		return (false);
2761 	}
2762 
2763 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr);
2764 	arena = extent_node_arena_get(&chunk->node);
2765 
2766 	if (oldsize < usize_max) {
2767 		bool ret = arena_ralloc_large_grow(arena, chunk, ptr, oldsize,
2768 		    usize_min, usize_max, zero);
2769 		if (config_fill && !ret && !zero) {
2770 			if (unlikely(opt_junk_alloc)) {
2771 				memset((void *)((uintptr_t)ptr + oldsize), 0xa5,
2772 				    isalloc(ptr, config_prof) - oldsize);
2773 			} else if (unlikely(opt_zero)) {
2774 				memset((void *)((uintptr_t)ptr + oldsize), 0,
2775 				    isalloc(ptr, config_prof) - oldsize);
2776 			}
2777 		}
2778 		return (ret);
2779 	}
2780 
2781 	assert(oldsize > usize_max);
2782 	/* Fill before shrinking in order avoid a race. */
2783 	arena_ralloc_junk_large(ptr, oldsize, usize_max);
2784 	arena_ralloc_large_shrink(arena, chunk, ptr, oldsize, usize_max);
2785 	return (false);
2786 }
2787 
2788 bool
2789 arena_ralloc_no_move(void *ptr, size_t oldsize, size_t size, size_t extra,
2790     bool zero)
2791 {
2792 	size_t usize_min, usize_max;
2793 
2794 	usize_min = s2u(size);
2795 	usize_max = s2u(size + extra);
2796 	if (likely(oldsize <= large_maxclass && usize_min <= large_maxclass)) {
2797 		/*
2798 		 * Avoid moving the allocation if the size class can be left the
2799 		 * same.
2800 		 */
2801 		if (oldsize <= SMALL_MAXCLASS) {
2802 			assert(arena_bin_info[size2index(oldsize)].reg_size ==
2803 			    oldsize);
2804 			if ((usize_max <= SMALL_MAXCLASS &&
2805 			    size2index(usize_max) == size2index(oldsize)) ||
2806 			    (size <= oldsize && usize_max >= oldsize))
2807 				return (false);
2808 		} else {
2809 			if (usize_max > SMALL_MAXCLASS) {
2810 				if (!arena_ralloc_large(ptr, oldsize, usize_min,
2811 				    usize_max, zero))
2812 					return (false);
2813 			}
2814 		}
2815 
2816 		/* Reallocation would require a move. */
2817 		return (true);
2818 	} else {
2819 		return (huge_ralloc_no_move(ptr, oldsize, usize_min, usize_max,
2820 		    zero));
2821 	}
2822 }
2823 
2824 static void *
2825 arena_ralloc_move_helper(tsd_t *tsd, arena_t *arena, size_t usize,
2826     size_t alignment, bool zero, tcache_t *tcache)
2827 {
2828 
2829 	if (alignment == 0)
2830 		return (arena_malloc(tsd, arena, usize, zero, tcache));
2831 	usize = sa2u(usize, alignment);
2832 	if (usize == 0)
2833 		return (NULL);
2834 	return (ipalloct(tsd, usize, alignment, zero, tcache, arena));
2835 }
2836 
2837 void *
2838 arena_ralloc(tsd_t *tsd, arena_t *arena, void *ptr, size_t oldsize, size_t size,
2839     size_t alignment, bool zero, tcache_t *tcache)
2840 {
2841 	void *ret;
2842 	size_t usize;
2843 
2844 	usize = s2u(size);
2845 	if (usize == 0)
2846 		return (NULL);
2847 
2848 	if (likely(usize <= large_maxclass)) {
2849 		size_t copysize;
2850 
2851 		/* Try to avoid moving the allocation. */
2852 		if (!arena_ralloc_no_move(ptr, oldsize, usize, 0, zero))
2853 			return (ptr);
2854 
2855 		/*
2856 		 * size and oldsize are different enough that we need to move
2857 		 * the object.  In that case, fall back to allocating new space
2858 		 * and copying.
2859 		 */
2860 		ret = arena_ralloc_move_helper(tsd, arena, usize, alignment,
2861 		    zero, tcache);
2862 		if (ret == NULL)
2863 			return (NULL);
2864 
2865 		/*
2866 		 * Junk/zero-filling were already done by
2867 		 * ipalloc()/arena_malloc().
2868 		 */
2869 
2870 		copysize = (usize < oldsize) ? usize : oldsize;
2871 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, copysize);
2872 		memcpy(ret, ptr, copysize);
2873 		isqalloc(tsd, ptr, oldsize, tcache);
2874 	} else {
2875 		ret = huge_ralloc(tsd, arena, ptr, oldsize, usize, alignment,
2876 		    zero, tcache);
2877 	}
2878 	return (ret);
2879 }
2880 
2881 dss_prec_t
2882 arena_dss_prec_get(arena_t *arena)
2883 {
2884 	dss_prec_t ret;
2885 
2886 	malloc_mutex_lock(&arena->lock);
2887 	ret = arena->dss_prec;
2888 	malloc_mutex_unlock(&arena->lock);
2889 	return (ret);
2890 }
2891 
2892 bool
2893 arena_dss_prec_set(arena_t *arena, dss_prec_t dss_prec)
2894 {
2895 
2896 	if (!have_dss)
2897 		return (dss_prec != dss_prec_disabled);
2898 	malloc_mutex_lock(&arena->lock);
2899 	arena->dss_prec = dss_prec;
2900 	malloc_mutex_unlock(&arena->lock);
2901 	return (false);
2902 }
2903 
2904 ssize_t
2905 arena_lg_dirty_mult_default_get(void)
2906 {
2907 
2908 	return ((ssize_t)atomic_read_z((size_t *)&lg_dirty_mult_default));
2909 }
2910 
2911 bool
2912 arena_lg_dirty_mult_default_set(ssize_t lg_dirty_mult)
2913 {
2914 
2915 	if (!arena_lg_dirty_mult_valid(lg_dirty_mult))
2916 		return (true);
2917 	atomic_write_z((size_t *)&lg_dirty_mult_default, (size_t)lg_dirty_mult);
2918 	return (false);
2919 }
2920 
2921 void
2922 arena_stats_merge(arena_t *arena, const char **dss, ssize_t *lg_dirty_mult,
2923     size_t *nactive, size_t *ndirty, arena_stats_t *astats,
2924     malloc_bin_stats_t *bstats, malloc_large_stats_t *lstats,
2925     malloc_huge_stats_t *hstats)
2926 {
2927 	unsigned i;
2928 
2929 	malloc_mutex_lock(&arena->lock);
2930 	*dss = dss_prec_names[arena->dss_prec];
2931 	*lg_dirty_mult = arena->lg_dirty_mult;
2932 	*nactive += arena->nactive;
2933 	*ndirty += arena->ndirty;
2934 
2935 	astats->mapped += arena->stats.mapped;
2936 	astats->npurge += arena->stats.npurge;
2937 	astats->nmadvise += arena->stats.nmadvise;
2938 	astats->purged += arena->stats.purged;
2939 	astats->metadata_mapped += arena->stats.metadata_mapped;
2940 	astats->metadata_allocated += arena_metadata_allocated_get(arena);
2941 	astats->allocated_large += arena->stats.allocated_large;
2942 	astats->nmalloc_large += arena->stats.nmalloc_large;
2943 	astats->ndalloc_large += arena->stats.ndalloc_large;
2944 	astats->nrequests_large += arena->stats.nrequests_large;
2945 	astats->allocated_huge += arena->stats.allocated_huge;
2946 	astats->nmalloc_huge += arena->stats.nmalloc_huge;
2947 	astats->ndalloc_huge += arena->stats.ndalloc_huge;
2948 
2949 	for (i = 0; i < nlclasses; i++) {
2950 		lstats[i].nmalloc += arena->stats.lstats[i].nmalloc;
2951 		lstats[i].ndalloc += arena->stats.lstats[i].ndalloc;
2952 		lstats[i].nrequests += arena->stats.lstats[i].nrequests;
2953 		lstats[i].curruns += arena->stats.lstats[i].curruns;
2954 	}
2955 
2956 	for (i = 0; i < nhclasses; i++) {
2957 		hstats[i].nmalloc += arena->stats.hstats[i].nmalloc;
2958 		hstats[i].ndalloc += arena->stats.hstats[i].ndalloc;
2959 		hstats[i].curhchunks += arena->stats.hstats[i].curhchunks;
2960 	}
2961 	malloc_mutex_unlock(&arena->lock);
2962 
2963 	for (i = 0; i < NBINS; i++) {
2964 		arena_bin_t *bin = &arena->bins[i];
2965 
2966 		malloc_mutex_lock(&bin->lock);
2967 		bstats[i].nmalloc += bin->stats.nmalloc;
2968 		bstats[i].ndalloc += bin->stats.ndalloc;
2969 		bstats[i].nrequests += bin->stats.nrequests;
2970 		bstats[i].curregs += bin->stats.curregs;
2971 		if (config_tcache) {
2972 			bstats[i].nfills += bin->stats.nfills;
2973 			bstats[i].nflushes += bin->stats.nflushes;
2974 		}
2975 		bstats[i].nruns += bin->stats.nruns;
2976 		bstats[i].reruns += bin->stats.reruns;
2977 		bstats[i].curruns += bin->stats.curruns;
2978 		malloc_mutex_unlock(&bin->lock);
2979 	}
2980 }
2981 
2982 arena_t *
2983 arena_new(unsigned ind)
2984 {
2985 	arena_t *arena;
2986 	unsigned i;
2987 	arena_bin_t *bin;
2988 
2989 	/*
2990 	 * Allocate arena, arena->lstats, and arena->hstats contiguously, mainly
2991 	 * because there is no way to clean up if base_alloc() OOMs.
2992 	 */
2993 	if (config_stats) {
2994 		arena = (arena_t *)base_alloc(CACHELINE_CEILING(sizeof(arena_t))
2995 		    + QUANTUM_CEILING(nlclasses * sizeof(malloc_large_stats_t) +
2996 		    nhclasses) * sizeof(malloc_huge_stats_t));
2997 	} else
2998 		arena = (arena_t *)base_alloc(sizeof(arena_t));
2999 	if (arena == NULL)
3000 		return (NULL);
3001 
3002 	arena->ind = ind;
3003 	arena->nthreads = 0;
3004 	if (malloc_mutex_init(&arena->lock))
3005 		return (NULL);
3006 
3007 	if (config_stats) {
3008 		memset(&arena->stats, 0, sizeof(arena_stats_t));
3009 		arena->stats.lstats = (malloc_large_stats_t *)((uintptr_t)arena
3010 		    + CACHELINE_CEILING(sizeof(arena_t)));
3011 		memset(arena->stats.lstats, 0, nlclasses *
3012 		    sizeof(malloc_large_stats_t));
3013 		arena->stats.hstats = (malloc_huge_stats_t *)((uintptr_t)arena
3014 		    + CACHELINE_CEILING(sizeof(arena_t)) +
3015 		    QUANTUM_CEILING(nlclasses * sizeof(malloc_large_stats_t)));
3016 		memset(arena->stats.hstats, 0, nhclasses *
3017 		    sizeof(malloc_huge_stats_t));
3018 		if (config_tcache)
3019 			ql_new(&arena->tcache_ql);
3020 	}
3021 
3022 	if (config_prof)
3023 		arena->prof_accumbytes = 0;
3024 
3025 	if (config_cache_oblivious) {
3026 		/*
3027 		 * A nondeterministic seed based on the address of arena reduces
3028 		 * the likelihood of lockstep non-uniform cache index
3029 		 * utilization among identical concurrent processes, but at the
3030 		 * cost of test repeatability.  For debug builds, instead use a
3031 		 * deterministic seed.
3032 		 */
3033 		arena->offset_state = config_debug ? ind :
3034 		    (uint64_t)(uintptr_t)arena;
3035 	}
3036 
3037 	arena->dss_prec = chunk_dss_prec_get();
3038 
3039 	arena->spare = NULL;
3040 
3041 	arena->lg_dirty_mult = arena_lg_dirty_mult_default_get();
3042 	arena->purging = false;
3043 	arena->nactive = 0;
3044 	arena->ndirty = 0;
3045 
3046 	arena_avail_tree_new(&arena->runs_avail);
3047 	qr_new(&arena->runs_dirty, rd_link);
3048 	qr_new(&arena->chunks_cache, cc_link);
3049 
3050 	ql_new(&arena->huge);
3051 	if (malloc_mutex_init(&arena->huge_mtx))
3052 		return (NULL);
3053 
3054 	extent_tree_szad_new(&arena->chunks_szad_cached);
3055 	extent_tree_ad_new(&arena->chunks_ad_cached);
3056 	extent_tree_szad_new(&arena->chunks_szad_retained);
3057 	extent_tree_ad_new(&arena->chunks_ad_retained);
3058 	if (malloc_mutex_init(&arena->chunks_mtx))
3059 		return (NULL);
3060 	ql_new(&arena->node_cache);
3061 	if (malloc_mutex_init(&arena->node_cache_mtx))
3062 		return (NULL);
3063 
3064 	arena->chunk_hooks = chunk_hooks_default;
3065 
3066 	/* Initialize bins. */
3067 	for (i = 0; i < NBINS; i++) {
3068 		bin = &arena->bins[i];
3069 		if (malloc_mutex_init(&bin->lock))
3070 			return (NULL);
3071 		bin->runcur = NULL;
3072 		arena_run_tree_new(&bin->runs);
3073 		if (config_stats)
3074 			memset(&bin->stats, 0, sizeof(malloc_bin_stats_t));
3075 	}
3076 
3077 	return (arena);
3078 }
3079 
3080 /*
3081  * Calculate bin_info->run_size such that it meets the following constraints:
3082  *
3083  *   *) bin_info->run_size <= arena_maxrun
3084  *   *) bin_info->nregs <= RUN_MAXREGS
3085  *
3086  * bin_info->nregs and bin_info->reg0_offset are also calculated here, since
3087  * these settings are all interdependent.
3088  */
3089 static void
3090 bin_info_run_size_calc(arena_bin_info_t *bin_info)
3091 {
3092 	size_t pad_size;
3093 	size_t try_run_size, perfect_run_size, actual_run_size;
3094 	uint32_t try_nregs, perfect_nregs, actual_nregs;
3095 
3096 	/*
3097 	 * Determine redzone size based on minimum alignment and minimum
3098 	 * redzone size.  Add padding to the end of the run if it is needed to
3099 	 * align the regions.  The padding allows each redzone to be half the
3100 	 * minimum alignment; without the padding, each redzone would have to
3101 	 * be twice as large in order to maintain alignment.
3102 	 */
3103 	if (config_fill && unlikely(opt_redzone)) {
3104 		size_t align_min = ZU(1) << (jemalloc_ffs(bin_info->reg_size) -
3105 		    1);
3106 		if (align_min <= REDZONE_MINSIZE) {
3107 			bin_info->redzone_size = REDZONE_MINSIZE;
3108 			pad_size = 0;
3109 		} else {
3110 			bin_info->redzone_size = align_min >> 1;
3111 			pad_size = bin_info->redzone_size;
3112 		}
3113 	} else {
3114 		bin_info->redzone_size = 0;
3115 		pad_size = 0;
3116 	}
3117 	bin_info->reg_interval = bin_info->reg_size +
3118 	    (bin_info->redzone_size << 1);
3119 
3120 	/*
3121 	 * Compute run size under ideal conditions (no redzones, no limit on run
3122 	 * size).
3123 	 */
3124 	try_run_size = PAGE;
3125 	try_nregs = try_run_size / bin_info->reg_size;
3126 	do {
3127 		perfect_run_size = try_run_size;
3128 		perfect_nregs = try_nregs;
3129 
3130 		try_run_size += PAGE;
3131 		try_nregs = try_run_size / bin_info->reg_size;
3132 	} while (perfect_run_size != perfect_nregs * bin_info->reg_size);
3133 	assert(perfect_nregs <= RUN_MAXREGS);
3134 
3135 	actual_run_size = perfect_run_size;
3136 	actual_nregs = (actual_run_size - pad_size) / bin_info->reg_interval;
3137 
3138 	/*
3139 	 * Redzones can require enough padding that not even a single region can
3140 	 * fit within the number of pages that would normally be dedicated to a
3141 	 * run for this size class.  Increase the run size until at least one
3142 	 * region fits.
3143 	 */
3144 	while (actual_nregs == 0) {
3145 		assert(config_fill && unlikely(opt_redzone));
3146 
3147 		actual_run_size += PAGE;
3148 		actual_nregs = (actual_run_size - pad_size) /
3149 		    bin_info->reg_interval;
3150 	}
3151 
3152 	/*
3153 	 * Make sure that the run will fit within an arena chunk.
3154 	 */
3155 	while (actual_run_size > arena_maxrun) {
3156 		actual_run_size -= PAGE;
3157 		actual_nregs = (actual_run_size - pad_size) /
3158 		    bin_info->reg_interval;
3159 	}
3160 	assert(actual_nregs > 0);
3161 	assert(actual_run_size == s2u(actual_run_size));
3162 
3163 	/* Copy final settings. */
3164 	bin_info->run_size = actual_run_size;
3165 	bin_info->nregs = actual_nregs;
3166 	bin_info->reg0_offset = actual_run_size - (actual_nregs *
3167 	    bin_info->reg_interval) - pad_size + bin_info->redzone_size;
3168 
3169 	if (actual_run_size > small_maxrun)
3170 		small_maxrun = actual_run_size;
3171 
3172 	assert(bin_info->reg0_offset - bin_info->redzone_size + (bin_info->nregs
3173 	    * bin_info->reg_interval) + pad_size == bin_info->run_size);
3174 }
3175 
3176 static void
3177 bin_info_init(void)
3178 {
3179 	arena_bin_info_t *bin_info;
3180 
3181 #define	BIN_INFO_INIT_bin_yes(index, size)				\
3182 	bin_info = &arena_bin_info[index];				\
3183 	bin_info->reg_size = size;					\
3184 	bin_info_run_size_calc(bin_info);				\
3185 	bitmap_info_init(&bin_info->bitmap_info, bin_info->nregs);
3186 #define	BIN_INFO_INIT_bin_no(index, size)
3187 #define	SC(index, lg_grp, lg_delta, ndelta, bin, lg_delta_lookup)	\
3188 	BIN_INFO_INIT_bin_##bin(index, (ZU(1)<<lg_grp) + (ZU(ndelta)<<lg_delta))
3189 	SIZE_CLASSES
3190 #undef BIN_INFO_INIT_bin_yes
3191 #undef BIN_INFO_INIT_bin_no
3192 #undef SC
3193 }
3194 
3195 static bool
3196 small_run_size_init(void)
3197 {
3198 
3199 	assert(small_maxrun != 0);
3200 
3201 	small_run_tab = (bool *)base_alloc(sizeof(bool) * (small_maxrun >>
3202 	    LG_PAGE));
3203 	if (small_run_tab == NULL)
3204 		return (true);
3205 
3206 #define	TAB_INIT_bin_yes(index, size) {					\
3207 		arena_bin_info_t *bin_info = &arena_bin_info[index];	\
3208 		small_run_tab[bin_info->run_size >> LG_PAGE] = true;	\
3209 	}
3210 #define	TAB_INIT_bin_no(index, size)
3211 #define	SC(index, lg_grp, lg_delta, ndelta, bin, lg_delta_lookup)	\
3212 	TAB_INIT_bin_##bin(index, (ZU(1)<<lg_grp) + (ZU(ndelta)<<lg_delta))
3213 	SIZE_CLASSES
3214 #undef TAB_INIT_bin_yes
3215 #undef TAB_INIT_bin_no
3216 #undef SC
3217 
3218 	return (false);
3219 }
3220 
3221 bool
3222 arena_boot(void)
3223 {
3224 	unsigned i;
3225 
3226 	arena_lg_dirty_mult_default_set(opt_lg_dirty_mult);
3227 
3228 	/*
3229 	 * Compute the header size such that it is large enough to contain the
3230 	 * page map.  The page map is biased to omit entries for the header
3231 	 * itself, so some iteration is necessary to compute the map bias.
3232 	 *
3233 	 * 1) Compute safe header_size and map_bias values that include enough
3234 	 *    space for an unbiased page map.
3235 	 * 2) Refine map_bias based on (1) to omit the header pages in the page
3236 	 *    map.  The resulting map_bias may be one too small.
3237 	 * 3) Refine map_bias based on (2).  The result will be >= the result
3238 	 *    from (2), and will always be correct.
3239 	 */
3240 	map_bias = 0;
3241 	for (i = 0; i < 3; i++) {
3242 		size_t header_size = offsetof(arena_chunk_t, map_bits) +
3243 		    ((sizeof(arena_chunk_map_bits_t) +
3244 		    sizeof(arena_chunk_map_misc_t)) * (chunk_npages-map_bias));
3245 		map_bias = (header_size + PAGE_MASK) >> LG_PAGE;
3246 	}
3247 	assert(map_bias > 0);
3248 
3249 	map_misc_offset = offsetof(arena_chunk_t, map_bits) +
3250 	    sizeof(arena_chunk_map_bits_t) * (chunk_npages-map_bias);
3251 
3252 	arena_maxrun = chunksize - (map_bias << LG_PAGE);
3253 	assert(arena_maxrun > 0);
3254 	large_maxclass = index2size(size2index(chunksize)-1);
3255 	if (large_maxclass > arena_maxrun) {
3256 		/*
3257 		 * For small chunk sizes it's possible for there to be fewer
3258 		 * non-header pages available than are necessary to serve the
3259 		 * size classes just below chunksize.
3260 		 */
3261 		large_maxclass = arena_maxrun;
3262 	}
3263 	assert(large_maxclass > 0);
3264 	nlclasses = size2index(large_maxclass) - size2index(SMALL_MAXCLASS);
3265 	nhclasses = NSIZES - nlclasses - NBINS;
3266 
3267 	bin_info_init();
3268 	return (small_run_size_init());
3269 }
3270 
3271 void
3272 arena_prefork(arena_t *arena)
3273 {
3274 	unsigned i;
3275 
3276 	malloc_mutex_prefork(&arena->lock);
3277 	malloc_mutex_prefork(&arena->huge_mtx);
3278 	malloc_mutex_prefork(&arena->chunks_mtx);
3279 	malloc_mutex_prefork(&arena->node_cache_mtx);
3280 	for (i = 0; i < NBINS; i++)
3281 		malloc_mutex_prefork(&arena->bins[i].lock);
3282 }
3283 
3284 void
3285 arena_postfork_parent(arena_t *arena)
3286 {
3287 	unsigned i;
3288 
3289 	for (i = 0; i < NBINS; i++)
3290 		malloc_mutex_postfork_parent(&arena->bins[i].lock);
3291 	malloc_mutex_postfork_parent(&arena->node_cache_mtx);
3292 	malloc_mutex_postfork_parent(&arena->chunks_mtx);
3293 	malloc_mutex_postfork_parent(&arena->huge_mtx);
3294 	malloc_mutex_postfork_parent(&arena->lock);
3295 }
3296 
3297 void
3298 arena_postfork_child(arena_t *arena)
3299 {
3300 	unsigned i;
3301 
3302 	for (i = 0; i < NBINS; i++)
3303 		malloc_mutex_postfork_child(&arena->bins[i].lock);
3304 	malloc_mutex_postfork_child(&arena->node_cache_mtx);
3305 	malloc_mutex_postfork_child(&arena->chunks_mtx);
3306 	malloc_mutex_postfork_child(&arena->huge_mtx);
3307 	malloc_mutex_postfork_child(&arena->lock);
3308 }
3309