xref: /freebsd/contrib/jemalloc/src/arena.c (revision 342af4d5efec74bb4bc11261fdd9991c53616f54)
1 #define	JEMALLOC_ARENA_C_
2 #include "jemalloc/internal/jemalloc_internal.h"
3 
4 /******************************************************************************/
5 /* Data. */
6 
7 purge_mode_t	opt_purge = PURGE_DEFAULT;
8 const char	*purge_mode_names[] = {
9 	"ratio",
10 	"decay",
11 	"N/A"
12 };
13 ssize_t		opt_lg_dirty_mult = LG_DIRTY_MULT_DEFAULT;
14 static ssize_t	lg_dirty_mult_default;
15 ssize_t		opt_decay_time = DECAY_TIME_DEFAULT;
16 static ssize_t	decay_time_default;
17 
18 arena_bin_info_t	arena_bin_info[NBINS];
19 
20 size_t		map_bias;
21 size_t		map_misc_offset;
22 size_t		arena_maxrun; /* Max run size for arenas. */
23 size_t		large_maxclass; /* Max large size class. */
24 size_t		run_quantize_max; /* Max run_quantize_*() input. */
25 static size_t	small_maxrun; /* Max run size for small size classes. */
26 static bool	*small_run_tab; /* Valid small run page multiples. */
27 static size_t	*run_quantize_floor_tab; /* run_quantize_floor() memoization. */
28 static size_t	*run_quantize_ceil_tab; /* run_quantize_ceil() memoization. */
29 unsigned	nlclasses; /* Number of large size classes. */
30 unsigned	nhclasses; /* Number of huge size classes. */
31 static szind_t	runs_avail_bias; /* Size index for first runs_avail tree. */
32 static szind_t	runs_avail_nclasses; /* Number of runs_avail trees. */
33 
34 /******************************************************************************/
35 /*
36  * Function prototypes for static functions that are referenced prior to
37  * definition.
38  */
39 
40 static void	arena_purge_to_limit(arena_t *arena, size_t ndirty_limit);
41 static void	arena_run_dalloc(arena_t *arena, arena_run_t *run, bool dirty,
42     bool cleaned, bool decommitted);
43 static void	arena_dalloc_bin_run(arena_t *arena, arena_chunk_t *chunk,
44     arena_run_t *run, arena_bin_t *bin);
45 static void	arena_bin_lower_run(arena_t *arena, arena_chunk_t *chunk,
46     arena_run_t *run, arena_bin_t *bin);
47 
48 /******************************************************************************/
49 
50 JEMALLOC_INLINE_C size_t
51 arena_miscelm_size_get(const arena_chunk_map_misc_t *miscelm)
52 {
53 	arena_chunk_t *chunk;
54 	size_t pageind, mapbits;
55 
56 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(miscelm);
57 	pageind = arena_miscelm_to_pageind(miscelm);
58 	mapbits = arena_mapbits_get(chunk, pageind);
59 	return (arena_mapbits_size_decode(mapbits));
60 }
61 
62 JEMALLOC_INLINE_C int
63 arena_run_addr_comp(const arena_chunk_map_misc_t *a,
64     const arena_chunk_map_misc_t *b)
65 {
66 	uintptr_t a_miscelm = (uintptr_t)a;
67 	uintptr_t b_miscelm = (uintptr_t)b;
68 
69 	assert(a != NULL);
70 	assert(b != NULL);
71 
72 	return ((a_miscelm > b_miscelm) - (a_miscelm < b_miscelm));
73 }
74 
75 /* Generate red-black tree functions. */
76 rb_gen(static UNUSED, arena_run_tree_, arena_run_tree_t, arena_chunk_map_misc_t,
77     rb_link, arena_run_addr_comp)
78 
79 static size_t
80 run_quantize_floor_compute(size_t size)
81 {
82 	size_t qsize;
83 
84 	assert(size != 0);
85 	assert(size == PAGE_CEILING(size));
86 
87 	/* Don't change sizes that are valid small run sizes. */
88 	if (size <= small_maxrun && small_run_tab[size >> LG_PAGE])
89 		return (size);
90 
91 	/*
92 	 * Round down to the nearest run size that can actually be requested
93 	 * during normal large allocation.  Add large_pad so that cache index
94 	 * randomization can offset the allocation from the page boundary.
95 	 */
96 	qsize = index2size(size2index(size - large_pad + 1) - 1) + large_pad;
97 	if (qsize <= SMALL_MAXCLASS + large_pad)
98 		return (run_quantize_floor_compute(size - large_pad));
99 	assert(qsize <= size);
100 	return (qsize);
101 }
102 
103 static size_t
104 run_quantize_ceil_compute_hard(size_t size)
105 {
106 	size_t large_run_size_next;
107 
108 	assert(size != 0);
109 	assert(size == PAGE_CEILING(size));
110 
111 	/*
112 	 * Return the next quantized size greater than the input size.
113 	 * Quantized sizes comprise the union of run sizes that back small
114 	 * region runs, and run sizes that back large regions with no explicit
115 	 * alignment constraints.
116 	 */
117 
118 	if (size > SMALL_MAXCLASS) {
119 		large_run_size_next = PAGE_CEILING(index2size(size2index(size -
120 		    large_pad) + 1) + large_pad);
121 	} else
122 		large_run_size_next = SIZE_T_MAX;
123 	if (size >= small_maxrun)
124 		return (large_run_size_next);
125 
126 	while (true) {
127 		size += PAGE;
128 		assert(size <= small_maxrun);
129 		if (small_run_tab[size >> LG_PAGE]) {
130 			if (large_run_size_next < size)
131 				return (large_run_size_next);
132 			return (size);
133 		}
134 	}
135 }
136 
137 static size_t
138 run_quantize_ceil_compute(size_t size)
139 {
140 	size_t qsize = run_quantize_floor_compute(size);
141 
142 	if (qsize < size) {
143 		/*
144 		 * Skip a quantization that may have an adequately large run,
145 		 * because under-sized runs may be mixed in.  This only happens
146 		 * when an unusual size is requested, i.e. for aligned
147 		 * allocation, and is just one of several places where linear
148 		 * search would potentially find sufficiently aligned available
149 		 * memory somewhere lower.
150 		 */
151 		qsize = run_quantize_ceil_compute_hard(qsize);
152 	}
153 	return (qsize);
154 }
155 
156 #ifdef JEMALLOC_JET
157 #undef run_quantize_floor
158 #define	run_quantize_floor JEMALLOC_N(run_quantize_floor_impl)
159 #endif
160 static size_t
161 run_quantize_floor(size_t size)
162 {
163 	size_t ret;
164 
165 	assert(size > 0);
166 	assert(size <= run_quantize_max);
167 	assert((size & PAGE_MASK) == 0);
168 
169 	ret = run_quantize_floor_tab[(size >> LG_PAGE) - 1];
170 	assert(ret == run_quantize_floor_compute(size));
171 	return (ret);
172 }
173 #ifdef JEMALLOC_JET
174 #undef run_quantize_floor
175 #define	run_quantize_floor JEMALLOC_N(run_quantize_floor)
176 run_quantize_t *run_quantize_floor = JEMALLOC_N(run_quantize_floor_impl);
177 #endif
178 
179 #ifdef JEMALLOC_JET
180 #undef run_quantize_ceil
181 #define	run_quantize_ceil JEMALLOC_N(run_quantize_ceil_impl)
182 #endif
183 static size_t
184 run_quantize_ceil(size_t size)
185 {
186 	size_t ret;
187 
188 	assert(size > 0);
189 	assert(size <= run_quantize_max);
190 	assert((size & PAGE_MASK) == 0);
191 
192 	ret = run_quantize_ceil_tab[(size >> LG_PAGE) - 1];
193 	assert(ret == run_quantize_ceil_compute(size));
194 	return (ret);
195 }
196 #ifdef JEMALLOC_JET
197 #undef run_quantize_ceil
198 #define	run_quantize_ceil JEMALLOC_N(run_quantize_ceil)
199 run_quantize_t *run_quantize_ceil = JEMALLOC_N(run_quantize_ceil_impl);
200 #endif
201 
202 static arena_run_tree_t *
203 arena_runs_avail_get(arena_t *arena, szind_t ind)
204 {
205 
206 	assert(ind >= runs_avail_bias);
207 	assert(ind - runs_avail_bias < runs_avail_nclasses);
208 
209 	return (&arena->runs_avail[ind - runs_avail_bias]);
210 }
211 
212 static void
213 arena_avail_insert(arena_t *arena, arena_chunk_t *chunk, size_t pageind,
214     size_t npages)
215 {
216 	szind_t ind = size2index(run_quantize_floor(arena_miscelm_size_get(
217 	    arena_miscelm_get(chunk, pageind))));
218 	assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >>
219 	    LG_PAGE));
220 	arena_run_tree_insert(arena_runs_avail_get(arena, ind),
221 	    arena_miscelm_get(chunk, pageind));
222 }
223 
224 static void
225 arena_avail_remove(arena_t *arena, arena_chunk_t *chunk, size_t pageind,
226     size_t npages)
227 {
228 	szind_t ind = size2index(run_quantize_floor(arena_miscelm_size_get(
229 	    arena_miscelm_get(chunk, pageind))));
230 	assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >>
231 	    LG_PAGE));
232 	arena_run_tree_remove(arena_runs_avail_get(arena, ind),
233 	    arena_miscelm_get(chunk, pageind));
234 }
235 
236 static void
237 arena_run_dirty_insert(arena_t *arena, arena_chunk_t *chunk, size_t pageind,
238     size_t npages)
239 {
240 	arena_chunk_map_misc_t *miscelm = arena_miscelm_get(chunk, pageind);
241 
242 	assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >>
243 	    LG_PAGE));
244 	assert(arena_mapbits_dirty_get(chunk, pageind) == CHUNK_MAP_DIRTY);
245 	assert(arena_mapbits_dirty_get(chunk, pageind+npages-1) ==
246 	    CHUNK_MAP_DIRTY);
247 
248 	qr_new(&miscelm->rd, rd_link);
249 	qr_meld(&arena->runs_dirty, &miscelm->rd, rd_link);
250 	arena->ndirty += npages;
251 }
252 
253 static void
254 arena_run_dirty_remove(arena_t *arena, arena_chunk_t *chunk, size_t pageind,
255     size_t npages)
256 {
257 	arena_chunk_map_misc_t *miscelm = arena_miscelm_get(chunk, pageind);
258 
259 	assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >>
260 	    LG_PAGE));
261 	assert(arena_mapbits_dirty_get(chunk, pageind) == CHUNK_MAP_DIRTY);
262 	assert(arena_mapbits_dirty_get(chunk, pageind+npages-1) ==
263 	    CHUNK_MAP_DIRTY);
264 
265 	qr_remove(&miscelm->rd, rd_link);
266 	assert(arena->ndirty >= npages);
267 	arena->ndirty -= npages;
268 }
269 
270 static size_t
271 arena_chunk_dirty_npages(const extent_node_t *node)
272 {
273 
274 	return (extent_node_size_get(node) >> LG_PAGE);
275 }
276 
277 void
278 arena_chunk_cache_maybe_insert(arena_t *arena, extent_node_t *node, bool cache)
279 {
280 
281 	if (cache) {
282 		extent_node_dirty_linkage_init(node);
283 		extent_node_dirty_insert(node, &arena->runs_dirty,
284 		    &arena->chunks_cache);
285 		arena->ndirty += arena_chunk_dirty_npages(node);
286 	}
287 }
288 
289 void
290 arena_chunk_cache_maybe_remove(arena_t *arena, extent_node_t *node, bool dirty)
291 {
292 
293 	if (dirty) {
294 		extent_node_dirty_remove(node);
295 		assert(arena->ndirty >= arena_chunk_dirty_npages(node));
296 		arena->ndirty -= arena_chunk_dirty_npages(node);
297 	}
298 }
299 
300 JEMALLOC_INLINE_C void *
301 arena_run_reg_alloc(arena_run_t *run, arena_bin_info_t *bin_info)
302 {
303 	void *ret;
304 	size_t regind;
305 	arena_chunk_map_misc_t *miscelm;
306 	void *rpages;
307 
308 	assert(run->nfree > 0);
309 	assert(!bitmap_full(run->bitmap, &bin_info->bitmap_info));
310 
311 	regind = (unsigned)bitmap_sfu(run->bitmap, &bin_info->bitmap_info);
312 	miscelm = arena_run_to_miscelm(run);
313 	rpages = arena_miscelm_to_rpages(miscelm);
314 	ret = (void *)((uintptr_t)rpages + (uintptr_t)bin_info->reg0_offset +
315 	    (uintptr_t)(bin_info->reg_interval * regind));
316 	run->nfree--;
317 	return (ret);
318 }
319 
320 JEMALLOC_INLINE_C void
321 arena_run_reg_dalloc(arena_run_t *run, void *ptr)
322 {
323 	arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
324 	size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
325 	size_t mapbits = arena_mapbits_get(chunk, pageind);
326 	szind_t binind = arena_ptr_small_binind_get(ptr, mapbits);
327 	arena_bin_info_t *bin_info = &arena_bin_info[binind];
328 	size_t regind = arena_run_regind(run, bin_info, ptr);
329 
330 	assert(run->nfree < bin_info->nregs);
331 	/* Freeing an interior pointer can cause assertion failure. */
332 	assert(((uintptr_t)ptr -
333 	    ((uintptr_t)arena_miscelm_to_rpages(arena_run_to_miscelm(run)) +
334 	    (uintptr_t)bin_info->reg0_offset)) %
335 	    (uintptr_t)bin_info->reg_interval == 0);
336 	assert((uintptr_t)ptr >=
337 	    (uintptr_t)arena_miscelm_to_rpages(arena_run_to_miscelm(run)) +
338 	    (uintptr_t)bin_info->reg0_offset);
339 	/* Freeing an unallocated pointer can cause assertion failure. */
340 	assert(bitmap_get(run->bitmap, &bin_info->bitmap_info, regind));
341 
342 	bitmap_unset(run->bitmap, &bin_info->bitmap_info, regind);
343 	run->nfree++;
344 }
345 
346 JEMALLOC_INLINE_C void
347 arena_run_zero(arena_chunk_t *chunk, size_t run_ind, size_t npages)
348 {
349 
350 	JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED((void *)((uintptr_t)chunk +
351 	    (run_ind << LG_PAGE)), (npages << LG_PAGE));
352 	memset((void *)((uintptr_t)chunk + (run_ind << LG_PAGE)), 0,
353 	    (npages << LG_PAGE));
354 }
355 
356 JEMALLOC_INLINE_C void
357 arena_run_page_mark_zeroed(arena_chunk_t *chunk, size_t run_ind)
358 {
359 
360 	JEMALLOC_VALGRIND_MAKE_MEM_DEFINED((void *)((uintptr_t)chunk + (run_ind
361 	    << LG_PAGE)), PAGE);
362 }
363 
364 JEMALLOC_INLINE_C void
365 arena_run_page_validate_zeroed(arena_chunk_t *chunk, size_t run_ind)
366 {
367 	size_t i;
368 	UNUSED size_t *p = (size_t *)((uintptr_t)chunk + (run_ind << LG_PAGE));
369 
370 	arena_run_page_mark_zeroed(chunk, run_ind);
371 	for (i = 0; i < PAGE / sizeof(size_t); i++)
372 		assert(p[i] == 0);
373 }
374 
375 static void
376 arena_nactive_add(arena_t *arena, size_t add_pages)
377 {
378 
379 	if (config_stats) {
380 		size_t cactive_add = CHUNK_CEILING((arena->nactive +
381 		    add_pages) << LG_PAGE) - CHUNK_CEILING(arena->nactive <<
382 		    LG_PAGE);
383 		if (cactive_add != 0)
384 			stats_cactive_add(cactive_add);
385 	}
386 	arena->nactive += add_pages;
387 }
388 
389 static void
390 arena_nactive_sub(arena_t *arena, size_t sub_pages)
391 {
392 
393 	if (config_stats) {
394 		size_t cactive_sub = CHUNK_CEILING(arena->nactive << LG_PAGE) -
395 		    CHUNK_CEILING((arena->nactive - sub_pages) << LG_PAGE);
396 		if (cactive_sub != 0)
397 			stats_cactive_sub(cactive_sub);
398 	}
399 	arena->nactive -= sub_pages;
400 }
401 
402 static void
403 arena_run_split_remove(arena_t *arena, arena_chunk_t *chunk, size_t run_ind,
404     size_t flag_dirty, size_t flag_decommitted, size_t need_pages)
405 {
406 	size_t total_pages, rem_pages;
407 
408 	assert(flag_dirty == 0 || flag_decommitted == 0);
409 
410 	total_pages = arena_mapbits_unallocated_size_get(chunk, run_ind) >>
411 	    LG_PAGE;
412 	assert(arena_mapbits_dirty_get(chunk, run_ind+total_pages-1) ==
413 	    flag_dirty);
414 	assert(need_pages <= total_pages);
415 	rem_pages = total_pages - need_pages;
416 
417 	arena_avail_remove(arena, chunk, run_ind, total_pages);
418 	if (flag_dirty != 0)
419 		arena_run_dirty_remove(arena, chunk, run_ind, total_pages);
420 	arena_nactive_add(arena, need_pages);
421 
422 	/* Keep track of trailing unused pages for later use. */
423 	if (rem_pages > 0) {
424 		size_t flags = flag_dirty | flag_decommitted;
425 		size_t flag_unzeroed_mask = (flags == 0) ?  CHUNK_MAP_UNZEROED :
426 		    0;
427 
428 		arena_mapbits_unallocated_set(chunk, run_ind+need_pages,
429 		    (rem_pages << LG_PAGE), flags |
430 		    (arena_mapbits_unzeroed_get(chunk, run_ind+need_pages) &
431 		    flag_unzeroed_mask));
432 		arena_mapbits_unallocated_set(chunk, run_ind+total_pages-1,
433 		    (rem_pages << LG_PAGE), flags |
434 		    (arena_mapbits_unzeroed_get(chunk, run_ind+total_pages-1) &
435 		    flag_unzeroed_mask));
436 		if (flag_dirty != 0) {
437 			arena_run_dirty_insert(arena, chunk, run_ind+need_pages,
438 			    rem_pages);
439 		}
440 		arena_avail_insert(arena, chunk, run_ind+need_pages, rem_pages);
441 	}
442 }
443 
444 static bool
445 arena_run_split_large_helper(arena_t *arena, arena_run_t *run, size_t size,
446     bool remove, bool zero)
447 {
448 	arena_chunk_t *chunk;
449 	arena_chunk_map_misc_t *miscelm;
450 	size_t flag_dirty, flag_decommitted, run_ind, need_pages;
451 	size_t flag_unzeroed_mask;
452 
453 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
454 	miscelm = arena_run_to_miscelm(run);
455 	run_ind = arena_miscelm_to_pageind(miscelm);
456 	flag_dirty = arena_mapbits_dirty_get(chunk, run_ind);
457 	flag_decommitted = arena_mapbits_decommitted_get(chunk, run_ind);
458 	need_pages = (size >> LG_PAGE);
459 	assert(need_pages > 0);
460 
461 	if (flag_decommitted != 0 && arena->chunk_hooks.commit(chunk, chunksize,
462 	    run_ind << LG_PAGE, size, arena->ind))
463 		return (true);
464 
465 	if (remove) {
466 		arena_run_split_remove(arena, chunk, run_ind, flag_dirty,
467 		    flag_decommitted, need_pages);
468 	}
469 
470 	if (zero) {
471 		if (flag_decommitted != 0) {
472 			/* The run is untouched, and therefore zeroed. */
473 			JEMALLOC_VALGRIND_MAKE_MEM_DEFINED((void
474 			    *)((uintptr_t)chunk + (run_ind << LG_PAGE)),
475 			    (need_pages << LG_PAGE));
476 		} else if (flag_dirty != 0) {
477 			/* The run is dirty, so all pages must be zeroed. */
478 			arena_run_zero(chunk, run_ind, need_pages);
479 		} else {
480 			/*
481 			 * The run is clean, so some pages may be zeroed (i.e.
482 			 * never before touched).
483 			 */
484 			size_t i;
485 			for (i = 0; i < need_pages; i++) {
486 				if (arena_mapbits_unzeroed_get(chunk, run_ind+i)
487 				    != 0)
488 					arena_run_zero(chunk, run_ind+i, 1);
489 				else if (config_debug) {
490 					arena_run_page_validate_zeroed(chunk,
491 					    run_ind+i);
492 				} else {
493 					arena_run_page_mark_zeroed(chunk,
494 					    run_ind+i);
495 				}
496 			}
497 		}
498 	} else {
499 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED((void *)((uintptr_t)chunk +
500 		    (run_ind << LG_PAGE)), (need_pages << LG_PAGE));
501 	}
502 
503 	/*
504 	 * Set the last element first, in case the run only contains one page
505 	 * (i.e. both statements set the same element).
506 	 */
507 	flag_unzeroed_mask = (flag_dirty | flag_decommitted) == 0 ?
508 	    CHUNK_MAP_UNZEROED : 0;
509 	arena_mapbits_large_set(chunk, run_ind+need_pages-1, 0, flag_dirty |
510 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
511 	    run_ind+need_pages-1)));
512 	arena_mapbits_large_set(chunk, run_ind, size, flag_dirty |
513 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk, run_ind)));
514 	return (false);
515 }
516 
517 static bool
518 arena_run_split_large(arena_t *arena, arena_run_t *run, size_t size, bool zero)
519 {
520 
521 	return (arena_run_split_large_helper(arena, run, size, true, zero));
522 }
523 
524 static bool
525 arena_run_init_large(arena_t *arena, arena_run_t *run, size_t size, bool zero)
526 {
527 
528 	return (arena_run_split_large_helper(arena, run, size, false, zero));
529 }
530 
531 static bool
532 arena_run_split_small(arena_t *arena, arena_run_t *run, size_t size,
533     szind_t binind)
534 {
535 	arena_chunk_t *chunk;
536 	arena_chunk_map_misc_t *miscelm;
537 	size_t flag_dirty, flag_decommitted, run_ind, need_pages, i;
538 
539 	assert(binind != BININD_INVALID);
540 
541 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
542 	miscelm = arena_run_to_miscelm(run);
543 	run_ind = arena_miscelm_to_pageind(miscelm);
544 	flag_dirty = arena_mapbits_dirty_get(chunk, run_ind);
545 	flag_decommitted = arena_mapbits_decommitted_get(chunk, run_ind);
546 	need_pages = (size >> LG_PAGE);
547 	assert(need_pages > 0);
548 
549 	if (flag_decommitted != 0 && arena->chunk_hooks.commit(chunk, chunksize,
550 	    run_ind << LG_PAGE, size, arena->ind))
551 		return (true);
552 
553 	arena_run_split_remove(arena, chunk, run_ind, flag_dirty,
554 	    flag_decommitted, need_pages);
555 
556 	for (i = 0; i < need_pages; i++) {
557 		size_t flag_unzeroed = arena_mapbits_unzeroed_get(chunk,
558 		    run_ind+i);
559 		arena_mapbits_small_set(chunk, run_ind+i, i, binind,
560 		    flag_unzeroed);
561 		if (config_debug && flag_dirty == 0 && flag_unzeroed == 0)
562 			arena_run_page_validate_zeroed(chunk, run_ind+i);
563 	}
564 	JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED((void *)((uintptr_t)chunk +
565 	    (run_ind << LG_PAGE)), (need_pages << LG_PAGE));
566 	return (false);
567 }
568 
569 static arena_chunk_t *
570 arena_chunk_init_spare(arena_t *arena)
571 {
572 	arena_chunk_t *chunk;
573 
574 	assert(arena->spare != NULL);
575 
576 	chunk = arena->spare;
577 	arena->spare = NULL;
578 
579 	assert(arena_mapbits_allocated_get(chunk, map_bias) == 0);
580 	assert(arena_mapbits_allocated_get(chunk, chunk_npages-1) == 0);
581 	assert(arena_mapbits_unallocated_size_get(chunk, map_bias) ==
582 	    arena_maxrun);
583 	assert(arena_mapbits_unallocated_size_get(chunk, chunk_npages-1) ==
584 	    arena_maxrun);
585 	assert(arena_mapbits_dirty_get(chunk, map_bias) ==
586 	    arena_mapbits_dirty_get(chunk, chunk_npages-1));
587 
588 	return (chunk);
589 }
590 
591 static bool
592 arena_chunk_register(arena_t *arena, arena_chunk_t *chunk, bool zero)
593 {
594 
595 	/*
596 	 * The extent node notion of "committed" doesn't directly apply to
597 	 * arena chunks.  Arbitrarily mark them as committed.  The commit state
598 	 * of runs is tracked individually, and upon chunk deallocation the
599 	 * entire chunk is in a consistent commit state.
600 	 */
601 	extent_node_init(&chunk->node, arena, chunk, chunksize, zero, true);
602 	extent_node_achunk_set(&chunk->node, true);
603 	return (chunk_register(chunk, &chunk->node));
604 }
605 
606 static arena_chunk_t *
607 arena_chunk_alloc_internal_hard(arena_t *arena, chunk_hooks_t *chunk_hooks,
608     bool *zero, bool *commit)
609 {
610 	arena_chunk_t *chunk;
611 
612 	malloc_mutex_unlock(&arena->lock);
613 
614 	chunk = (arena_chunk_t *)chunk_alloc_wrapper(arena, chunk_hooks, NULL,
615 	    chunksize, chunksize, zero, commit);
616 	if (chunk != NULL && !*commit) {
617 		/* Commit header. */
618 		if (chunk_hooks->commit(chunk, chunksize, 0, map_bias <<
619 		    LG_PAGE, arena->ind)) {
620 			chunk_dalloc_wrapper(arena, chunk_hooks,
621 			    (void *)chunk, chunksize, *commit);
622 			chunk = NULL;
623 		}
624 	}
625 	if (chunk != NULL && arena_chunk_register(arena, chunk, *zero)) {
626 		if (!*commit) {
627 			/* Undo commit of header. */
628 			chunk_hooks->decommit(chunk, chunksize, 0, map_bias <<
629 			    LG_PAGE, arena->ind);
630 		}
631 		chunk_dalloc_wrapper(arena, chunk_hooks, (void *)chunk,
632 		    chunksize, *commit);
633 		chunk = NULL;
634 	}
635 
636 	malloc_mutex_lock(&arena->lock);
637 	return (chunk);
638 }
639 
640 static arena_chunk_t *
641 arena_chunk_alloc_internal(arena_t *arena, bool *zero, bool *commit)
642 {
643 	arena_chunk_t *chunk;
644 	chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
645 
646 	chunk = chunk_alloc_cache(arena, &chunk_hooks, NULL, chunksize,
647 	    chunksize, zero, true);
648 	if (chunk != NULL) {
649 		if (arena_chunk_register(arena, chunk, *zero)) {
650 			chunk_dalloc_cache(arena, &chunk_hooks, chunk,
651 			    chunksize, true);
652 			return (NULL);
653 		}
654 		*commit = true;
655 	}
656 	if (chunk == NULL) {
657 		chunk = arena_chunk_alloc_internal_hard(arena, &chunk_hooks,
658 		    zero, commit);
659 	}
660 
661 	if (config_stats && chunk != NULL) {
662 		arena->stats.mapped += chunksize;
663 		arena->stats.metadata_mapped += (map_bias << LG_PAGE);
664 	}
665 
666 	return (chunk);
667 }
668 
669 static arena_chunk_t *
670 arena_chunk_init_hard(arena_t *arena)
671 {
672 	arena_chunk_t *chunk;
673 	bool zero, commit;
674 	size_t flag_unzeroed, flag_decommitted, i;
675 
676 	assert(arena->spare == NULL);
677 
678 	zero = false;
679 	commit = false;
680 	chunk = arena_chunk_alloc_internal(arena, &zero, &commit);
681 	if (chunk == NULL)
682 		return (NULL);
683 
684 	/*
685 	 * Initialize the map to contain one maximal free untouched run.  Mark
686 	 * the pages as zeroed if chunk_alloc() returned a zeroed or decommitted
687 	 * chunk.
688 	 */
689 	flag_unzeroed = (zero || !commit) ? 0 : CHUNK_MAP_UNZEROED;
690 	flag_decommitted = commit ? 0 : CHUNK_MAP_DECOMMITTED;
691 	arena_mapbits_unallocated_set(chunk, map_bias, arena_maxrun,
692 	    flag_unzeroed | flag_decommitted);
693 	/*
694 	 * There is no need to initialize the internal page map entries unless
695 	 * the chunk is not zeroed.
696 	 */
697 	if (!zero) {
698 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(
699 		    (void *)arena_bitselm_get(chunk, map_bias+1),
700 		    (size_t)((uintptr_t) arena_bitselm_get(chunk,
701 		    chunk_npages-1) - (uintptr_t)arena_bitselm_get(chunk,
702 		    map_bias+1)));
703 		for (i = map_bias+1; i < chunk_npages-1; i++)
704 			arena_mapbits_internal_set(chunk, i, flag_unzeroed);
705 	} else {
706 		JEMALLOC_VALGRIND_MAKE_MEM_DEFINED((void
707 		    *)arena_bitselm_get(chunk, map_bias+1), (size_t)((uintptr_t)
708 		    arena_bitselm_get(chunk, chunk_npages-1) -
709 		    (uintptr_t)arena_bitselm_get(chunk, map_bias+1)));
710 		if (config_debug) {
711 			for (i = map_bias+1; i < chunk_npages-1; i++) {
712 				assert(arena_mapbits_unzeroed_get(chunk, i) ==
713 				    flag_unzeroed);
714 			}
715 		}
716 	}
717 	arena_mapbits_unallocated_set(chunk, chunk_npages-1, arena_maxrun,
718 	    flag_unzeroed);
719 
720 	return (chunk);
721 }
722 
723 static arena_chunk_t *
724 arena_chunk_alloc(arena_t *arena)
725 {
726 	arena_chunk_t *chunk;
727 
728 	if (arena->spare != NULL)
729 		chunk = arena_chunk_init_spare(arena);
730 	else {
731 		chunk = arena_chunk_init_hard(arena);
732 		if (chunk == NULL)
733 			return (NULL);
734 	}
735 
736 	arena_avail_insert(arena, chunk, map_bias, chunk_npages-map_bias);
737 
738 	return (chunk);
739 }
740 
741 static void
742 arena_chunk_dalloc(arena_t *arena, arena_chunk_t *chunk)
743 {
744 
745 	assert(arena_mapbits_allocated_get(chunk, map_bias) == 0);
746 	assert(arena_mapbits_allocated_get(chunk, chunk_npages-1) == 0);
747 	assert(arena_mapbits_unallocated_size_get(chunk, map_bias) ==
748 	    arena_maxrun);
749 	assert(arena_mapbits_unallocated_size_get(chunk, chunk_npages-1) ==
750 	    arena_maxrun);
751 	assert(arena_mapbits_dirty_get(chunk, map_bias) ==
752 	    arena_mapbits_dirty_get(chunk, chunk_npages-1));
753 	assert(arena_mapbits_decommitted_get(chunk, map_bias) ==
754 	    arena_mapbits_decommitted_get(chunk, chunk_npages-1));
755 
756 	/* Remove run from runs_avail, so that the arena does not use it. */
757 	arena_avail_remove(arena, chunk, map_bias, chunk_npages-map_bias);
758 
759 	if (arena->spare != NULL) {
760 		arena_chunk_t *spare = arena->spare;
761 		chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
762 		bool committed;
763 
764 		arena->spare = chunk;
765 		if (arena_mapbits_dirty_get(spare, map_bias) != 0) {
766 			arena_run_dirty_remove(arena, spare, map_bias,
767 			    chunk_npages-map_bias);
768 		}
769 
770 		chunk_deregister(spare, &spare->node);
771 
772 		committed = (arena_mapbits_decommitted_get(spare, map_bias) ==
773 		    0);
774 		if (!committed) {
775 			/*
776 			 * Decommit the header.  Mark the chunk as decommitted
777 			 * even if header decommit fails, since treating a
778 			 * partially committed chunk as committed has a high
779 			 * potential for causing later access of decommitted
780 			 * memory.
781 			 */
782 			chunk_hooks = chunk_hooks_get(arena);
783 			chunk_hooks.decommit(spare, chunksize, 0, map_bias <<
784 			    LG_PAGE, arena->ind);
785 		}
786 
787 		chunk_dalloc_cache(arena, &chunk_hooks, (void *)spare,
788 		    chunksize, committed);
789 
790 		if (config_stats) {
791 			arena->stats.mapped -= chunksize;
792 			arena->stats.metadata_mapped -= (map_bias << LG_PAGE);
793 		}
794 	} else
795 		arena->spare = chunk;
796 }
797 
798 static void
799 arena_huge_malloc_stats_update(arena_t *arena, size_t usize)
800 {
801 	szind_t index = size2index(usize) - nlclasses - NBINS;
802 
803 	cassert(config_stats);
804 
805 	arena->stats.nmalloc_huge++;
806 	arena->stats.allocated_huge += usize;
807 	arena->stats.hstats[index].nmalloc++;
808 	arena->stats.hstats[index].curhchunks++;
809 }
810 
811 static void
812 arena_huge_malloc_stats_update_undo(arena_t *arena, size_t usize)
813 {
814 	szind_t index = size2index(usize) - nlclasses - NBINS;
815 
816 	cassert(config_stats);
817 
818 	arena->stats.nmalloc_huge--;
819 	arena->stats.allocated_huge -= usize;
820 	arena->stats.hstats[index].nmalloc--;
821 	arena->stats.hstats[index].curhchunks--;
822 }
823 
824 static void
825 arena_huge_dalloc_stats_update(arena_t *arena, size_t usize)
826 {
827 	szind_t index = size2index(usize) - nlclasses - NBINS;
828 
829 	cassert(config_stats);
830 
831 	arena->stats.ndalloc_huge++;
832 	arena->stats.allocated_huge -= usize;
833 	arena->stats.hstats[index].ndalloc++;
834 	arena->stats.hstats[index].curhchunks--;
835 }
836 
837 static void
838 arena_huge_dalloc_stats_update_undo(arena_t *arena, size_t usize)
839 {
840 	szind_t index = size2index(usize) - nlclasses - NBINS;
841 
842 	cassert(config_stats);
843 
844 	arena->stats.ndalloc_huge--;
845 	arena->stats.allocated_huge += usize;
846 	arena->stats.hstats[index].ndalloc--;
847 	arena->stats.hstats[index].curhchunks++;
848 }
849 
850 static void
851 arena_huge_ralloc_stats_update(arena_t *arena, size_t oldsize, size_t usize)
852 {
853 
854 	arena_huge_dalloc_stats_update(arena, oldsize);
855 	arena_huge_malloc_stats_update(arena, usize);
856 }
857 
858 static void
859 arena_huge_ralloc_stats_update_undo(arena_t *arena, size_t oldsize,
860     size_t usize)
861 {
862 
863 	arena_huge_dalloc_stats_update_undo(arena, oldsize);
864 	arena_huge_malloc_stats_update_undo(arena, usize);
865 }
866 
867 extent_node_t *
868 arena_node_alloc(arena_t *arena)
869 {
870 	extent_node_t *node;
871 
872 	malloc_mutex_lock(&arena->node_cache_mtx);
873 	node = ql_last(&arena->node_cache, ql_link);
874 	if (node == NULL) {
875 		malloc_mutex_unlock(&arena->node_cache_mtx);
876 		return (base_alloc(sizeof(extent_node_t)));
877 	}
878 	ql_tail_remove(&arena->node_cache, extent_node_t, ql_link);
879 	malloc_mutex_unlock(&arena->node_cache_mtx);
880 	return (node);
881 }
882 
883 void
884 arena_node_dalloc(arena_t *arena, extent_node_t *node)
885 {
886 
887 	malloc_mutex_lock(&arena->node_cache_mtx);
888 	ql_elm_new(node, ql_link);
889 	ql_tail_insert(&arena->node_cache, node, ql_link);
890 	malloc_mutex_unlock(&arena->node_cache_mtx);
891 }
892 
893 static void *
894 arena_chunk_alloc_huge_hard(arena_t *arena, chunk_hooks_t *chunk_hooks,
895     size_t usize, size_t alignment, bool *zero, size_t csize)
896 {
897 	void *ret;
898 	bool commit = true;
899 
900 	ret = chunk_alloc_wrapper(arena, chunk_hooks, NULL, csize, alignment,
901 	    zero, &commit);
902 	if (ret == NULL) {
903 		/* Revert optimistic stats updates. */
904 		malloc_mutex_lock(&arena->lock);
905 		if (config_stats) {
906 			arena_huge_malloc_stats_update_undo(arena, usize);
907 			arena->stats.mapped -= usize;
908 		}
909 		arena_nactive_sub(arena, usize >> LG_PAGE);
910 		malloc_mutex_unlock(&arena->lock);
911 	}
912 
913 	return (ret);
914 }
915 
916 void *
917 arena_chunk_alloc_huge(arena_t *arena, size_t usize, size_t alignment,
918     bool *zero)
919 {
920 	void *ret;
921 	chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
922 	size_t csize = CHUNK_CEILING(usize);
923 
924 	malloc_mutex_lock(&arena->lock);
925 
926 	/* Optimistically update stats. */
927 	if (config_stats) {
928 		arena_huge_malloc_stats_update(arena, usize);
929 		arena->stats.mapped += usize;
930 	}
931 	arena_nactive_add(arena, usize >> LG_PAGE);
932 
933 	ret = chunk_alloc_cache(arena, &chunk_hooks, NULL, csize, alignment,
934 	    zero, true);
935 	malloc_mutex_unlock(&arena->lock);
936 	if (ret == NULL) {
937 		ret = arena_chunk_alloc_huge_hard(arena, &chunk_hooks, usize,
938 		    alignment, zero, csize);
939 	}
940 
941 	return (ret);
942 }
943 
944 void
945 arena_chunk_dalloc_huge(arena_t *arena, void *chunk, size_t usize)
946 {
947 	chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
948 	size_t csize;
949 
950 	csize = CHUNK_CEILING(usize);
951 	malloc_mutex_lock(&arena->lock);
952 	if (config_stats) {
953 		arena_huge_dalloc_stats_update(arena, usize);
954 		arena->stats.mapped -= usize;
955 	}
956 	arena_nactive_sub(arena, usize >> LG_PAGE);
957 
958 	chunk_dalloc_cache(arena, &chunk_hooks, chunk, csize, true);
959 	malloc_mutex_unlock(&arena->lock);
960 }
961 
962 void
963 arena_chunk_ralloc_huge_similar(arena_t *arena, void *chunk, size_t oldsize,
964     size_t usize)
965 {
966 
967 	assert(CHUNK_CEILING(oldsize) == CHUNK_CEILING(usize));
968 	assert(oldsize != usize);
969 
970 	malloc_mutex_lock(&arena->lock);
971 	if (config_stats)
972 		arena_huge_ralloc_stats_update(arena, oldsize, usize);
973 	if (oldsize < usize)
974 		arena_nactive_add(arena, (usize - oldsize) >> LG_PAGE);
975 	else
976 		arena_nactive_sub(arena, (oldsize - usize) >> LG_PAGE);
977 	malloc_mutex_unlock(&arena->lock);
978 }
979 
980 void
981 arena_chunk_ralloc_huge_shrink(arena_t *arena, void *chunk, size_t oldsize,
982     size_t usize)
983 {
984 	size_t udiff = oldsize - usize;
985 	size_t cdiff = CHUNK_CEILING(oldsize) - CHUNK_CEILING(usize);
986 
987 	malloc_mutex_lock(&arena->lock);
988 	if (config_stats) {
989 		arena_huge_ralloc_stats_update(arena, oldsize, usize);
990 		if (cdiff != 0)
991 			arena->stats.mapped -= cdiff;
992 	}
993 	arena_nactive_sub(arena, udiff >> LG_PAGE);
994 
995 	if (cdiff != 0) {
996 		chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
997 		void *nchunk = (void *)((uintptr_t)chunk +
998 		    CHUNK_CEILING(usize));
999 
1000 		chunk_dalloc_cache(arena, &chunk_hooks, nchunk, cdiff, true);
1001 	}
1002 	malloc_mutex_unlock(&arena->lock);
1003 }
1004 
1005 static bool
1006 arena_chunk_ralloc_huge_expand_hard(arena_t *arena, chunk_hooks_t *chunk_hooks,
1007     void *chunk, size_t oldsize, size_t usize, bool *zero, void *nchunk,
1008     size_t udiff, size_t cdiff)
1009 {
1010 	bool err;
1011 	bool commit = true;
1012 
1013 	err = (chunk_alloc_wrapper(arena, chunk_hooks, nchunk, cdiff, chunksize,
1014 	    zero, &commit) == NULL);
1015 	if (err) {
1016 		/* Revert optimistic stats updates. */
1017 		malloc_mutex_lock(&arena->lock);
1018 		if (config_stats) {
1019 			arena_huge_ralloc_stats_update_undo(arena, oldsize,
1020 			    usize);
1021 			arena->stats.mapped -= cdiff;
1022 		}
1023 		arena_nactive_sub(arena, udiff >> LG_PAGE);
1024 		malloc_mutex_unlock(&arena->lock);
1025 	} else if (chunk_hooks->merge(chunk, CHUNK_CEILING(oldsize), nchunk,
1026 	    cdiff, true, arena->ind)) {
1027 		chunk_dalloc_arena(arena, chunk_hooks, nchunk, cdiff, *zero,
1028 		    true);
1029 		err = true;
1030 	}
1031 	return (err);
1032 }
1033 
1034 bool
1035 arena_chunk_ralloc_huge_expand(arena_t *arena, void *chunk, size_t oldsize,
1036     size_t usize, bool *zero)
1037 {
1038 	bool err;
1039 	chunk_hooks_t chunk_hooks = chunk_hooks_get(arena);
1040 	void *nchunk = (void *)((uintptr_t)chunk + CHUNK_CEILING(oldsize));
1041 	size_t udiff = usize - oldsize;
1042 	size_t cdiff = CHUNK_CEILING(usize) - CHUNK_CEILING(oldsize);
1043 
1044 	malloc_mutex_lock(&arena->lock);
1045 
1046 	/* Optimistically update stats. */
1047 	if (config_stats) {
1048 		arena_huge_ralloc_stats_update(arena, oldsize, usize);
1049 		arena->stats.mapped += cdiff;
1050 	}
1051 	arena_nactive_add(arena, udiff >> LG_PAGE);
1052 
1053 	err = (chunk_alloc_cache(arena, &arena->chunk_hooks, nchunk, cdiff,
1054 	    chunksize, zero, true) == NULL);
1055 	malloc_mutex_unlock(&arena->lock);
1056 	if (err) {
1057 		err = arena_chunk_ralloc_huge_expand_hard(arena, &chunk_hooks,
1058 		    chunk, oldsize, usize, zero, nchunk, udiff,
1059 		    cdiff);
1060 	} else if (chunk_hooks.merge(chunk, CHUNK_CEILING(oldsize), nchunk,
1061 	    cdiff, true, arena->ind)) {
1062 		chunk_dalloc_arena(arena, &chunk_hooks, nchunk, cdiff, *zero,
1063 		    true);
1064 		err = true;
1065 	}
1066 
1067 	return (err);
1068 }
1069 
1070 /*
1071  * Do first-best-fit run selection, i.e. select the lowest run that best fits.
1072  * Run sizes are indexed, so not all candidate runs are necessarily exactly the
1073  * same size.
1074  */
1075 static arena_run_t *
1076 arena_run_first_best_fit(arena_t *arena, size_t size)
1077 {
1078 	szind_t ind, i;
1079 
1080 	ind = size2index(run_quantize_ceil(size));
1081 	for (i = ind; i < runs_avail_nclasses + runs_avail_bias; i++) {
1082 		arena_chunk_map_misc_t *miscelm = arena_run_tree_first(
1083 		    arena_runs_avail_get(arena, i));
1084 		if (miscelm != NULL)
1085 			return (&miscelm->run);
1086 	}
1087 
1088 	return (NULL);
1089 }
1090 
1091 static arena_run_t *
1092 arena_run_alloc_large_helper(arena_t *arena, size_t size, bool zero)
1093 {
1094 	arena_run_t *run = arena_run_first_best_fit(arena, s2u(size));
1095 	if (run != NULL) {
1096 		if (arena_run_split_large(arena, run, size, zero))
1097 			run = NULL;
1098 	}
1099 	return (run);
1100 }
1101 
1102 static arena_run_t *
1103 arena_run_alloc_large(arena_t *arena, size_t size, bool zero)
1104 {
1105 	arena_chunk_t *chunk;
1106 	arena_run_t *run;
1107 
1108 	assert(size <= arena_maxrun);
1109 	assert(size == PAGE_CEILING(size));
1110 
1111 	/* Search the arena's chunks for the lowest best fit. */
1112 	run = arena_run_alloc_large_helper(arena, size, zero);
1113 	if (run != NULL)
1114 		return (run);
1115 
1116 	/*
1117 	 * No usable runs.  Create a new chunk from which to allocate the run.
1118 	 */
1119 	chunk = arena_chunk_alloc(arena);
1120 	if (chunk != NULL) {
1121 		run = &arena_miscelm_get(chunk, map_bias)->run;
1122 		if (arena_run_split_large(arena, run, size, zero))
1123 			run = NULL;
1124 		return (run);
1125 	}
1126 
1127 	/*
1128 	 * arena_chunk_alloc() failed, but another thread may have made
1129 	 * sufficient memory available while this one dropped arena->lock in
1130 	 * arena_chunk_alloc(), so search one more time.
1131 	 */
1132 	return (arena_run_alloc_large_helper(arena, size, zero));
1133 }
1134 
1135 static arena_run_t *
1136 arena_run_alloc_small_helper(arena_t *arena, size_t size, szind_t binind)
1137 {
1138 	arena_run_t *run = arena_run_first_best_fit(arena, size);
1139 	if (run != NULL) {
1140 		if (arena_run_split_small(arena, run, size, binind))
1141 			run = NULL;
1142 	}
1143 	return (run);
1144 }
1145 
1146 static arena_run_t *
1147 arena_run_alloc_small(arena_t *arena, size_t size, szind_t binind)
1148 {
1149 	arena_chunk_t *chunk;
1150 	arena_run_t *run;
1151 
1152 	assert(size <= arena_maxrun);
1153 	assert(size == PAGE_CEILING(size));
1154 	assert(binind != BININD_INVALID);
1155 
1156 	/* Search the arena's chunks for the lowest best fit. */
1157 	run = arena_run_alloc_small_helper(arena, size, binind);
1158 	if (run != NULL)
1159 		return (run);
1160 
1161 	/*
1162 	 * No usable runs.  Create a new chunk from which to allocate the run.
1163 	 */
1164 	chunk = arena_chunk_alloc(arena);
1165 	if (chunk != NULL) {
1166 		run = &arena_miscelm_get(chunk, map_bias)->run;
1167 		if (arena_run_split_small(arena, run, size, binind))
1168 			run = NULL;
1169 		return (run);
1170 	}
1171 
1172 	/*
1173 	 * arena_chunk_alloc() failed, but another thread may have made
1174 	 * sufficient memory available while this one dropped arena->lock in
1175 	 * arena_chunk_alloc(), so search one more time.
1176 	 */
1177 	return (arena_run_alloc_small_helper(arena, size, binind));
1178 }
1179 
1180 static bool
1181 arena_lg_dirty_mult_valid(ssize_t lg_dirty_mult)
1182 {
1183 
1184 	return (lg_dirty_mult >= -1 && lg_dirty_mult < (ssize_t)(sizeof(size_t)
1185 	    << 3));
1186 }
1187 
1188 ssize_t
1189 arena_lg_dirty_mult_get(arena_t *arena)
1190 {
1191 	ssize_t lg_dirty_mult;
1192 
1193 	malloc_mutex_lock(&arena->lock);
1194 	lg_dirty_mult = arena->lg_dirty_mult;
1195 	malloc_mutex_unlock(&arena->lock);
1196 
1197 	return (lg_dirty_mult);
1198 }
1199 
1200 bool
1201 arena_lg_dirty_mult_set(arena_t *arena, ssize_t lg_dirty_mult)
1202 {
1203 
1204 	if (!arena_lg_dirty_mult_valid(lg_dirty_mult))
1205 		return (true);
1206 
1207 	malloc_mutex_lock(&arena->lock);
1208 	arena->lg_dirty_mult = lg_dirty_mult;
1209 	arena_maybe_purge(arena);
1210 	malloc_mutex_unlock(&arena->lock);
1211 
1212 	return (false);
1213 }
1214 
1215 static void
1216 arena_decay_deadline_init(arena_t *arena)
1217 {
1218 
1219 	assert(opt_purge == purge_mode_decay);
1220 
1221 	/*
1222 	 * Generate a new deadline that is uniformly random within the next
1223 	 * epoch after the current one.
1224 	 */
1225 	nstime_copy(&arena->decay_deadline, &arena->decay_epoch);
1226 	nstime_add(&arena->decay_deadline, &arena->decay_interval);
1227 	if (arena->decay_time > 0) {
1228 		nstime_t jitter;
1229 
1230 		nstime_init(&jitter, prng_range(&arena->decay_jitter_state,
1231 		    nstime_ns(&arena->decay_interval)));
1232 		nstime_add(&arena->decay_deadline, &jitter);
1233 	}
1234 }
1235 
1236 static bool
1237 arena_decay_deadline_reached(const arena_t *arena, const nstime_t *time)
1238 {
1239 
1240 	assert(opt_purge == purge_mode_decay);
1241 
1242 	return (nstime_compare(&arena->decay_deadline, time) <= 0);
1243 }
1244 
1245 static size_t
1246 arena_decay_backlog_npages_limit(const arena_t *arena)
1247 {
1248 	static const uint64_t h_steps[] = {
1249 #define	STEP(step, h, x, y) \
1250 		h,
1251 		SMOOTHSTEP
1252 #undef STEP
1253 	};
1254 	uint64_t sum;
1255 	size_t npages_limit_backlog;
1256 	unsigned i;
1257 
1258 	assert(opt_purge == purge_mode_decay);
1259 
1260 	/*
1261 	 * For each element of decay_backlog, multiply by the corresponding
1262 	 * fixed-point smoothstep decay factor.  Sum the products, then divide
1263 	 * to round down to the nearest whole number of pages.
1264 	 */
1265 	sum = 0;
1266 	for (i = 0; i < SMOOTHSTEP_NSTEPS; i++)
1267 		sum += arena->decay_backlog[i] * h_steps[i];
1268 	npages_limit_backlog = (sum >> SMOOTHSTEP_BFP);
1269 
1270 	return (npages_limit_backlog);
1271 }
1272 
1273 static void
1274 arena_decay_epoch_advance(arena_t *arena, const nstime_t *time)
1275 {
1276 	uint64_t nadvance;
1277 	nstime_t delta;
1278 	size_t ndirty_delta;
1279 
1280 	assert(opt_purge == purge_mode_decay);
1281 	assert(arena_decay_deadline_reached(arena, time));
1282 
1283 	nstime_copy(&delta, time);
1284 	nstime_subtract(&delta, &arena->decay_epoch);
1285 	nadvance = nstime_divide(&delta, &arena->decay_interval);
1286 	assert(nadvance > 0);
1287 
1288 	/* Add nadvance decay intervals to epoch. */
1289 	nstime_copy(&delta, &arena->decay_interval);
1290 	nstime_imultiply(&delta, nadvance);
1291 	nstime_add(&arena->decay_epoch, &delta);
1292 
1293 	/* Set a new deadline. */
1294 	arena_decay_deadline_init(arena);
1295 
1296 	/* Update the backlog. */
1297 	if (nadvance >= SMOOTHSTEP_NSTEPS) {
1298 		memset(arena->decay_backlog, 0, (SMOOTHSTEP_NSTEPS-1) *
1299 		    sizeof(size_t));
1300 	} else {
1301 		memmove(arena->decay_backlog, &arena->decay_backlog[nadvance],
1302 		    (SMOOTHSTEP_NSTEPS - nadvance) * sizeof(size_t));
1303 		if (nadvance > 1) {
1304 			memset(&arena->decay_backlog[SMOOTHSTEP_NSTEPS -
1305 			    nadvance], 0, (nadvance-1) * sizeof(size_t));
1306 		}
1307 	}
1308 	ndirty_delta = (arena->ndirty > arena->decay_ndirty) ? arena->ndirty -
1309 	    arena->decay_ndirty : 0;
1310 	arena->decay_ndirty = arena->ndirty;
1311 	arena->decay_backlog[SMOOTHSTEP_NSTEPS-1] = ndirty_delta;
1312 	arena->decay_backlog_npages_limit =
1313 	    arena_decay_backlog_npages_limit(arena);
1314 }
1315 
1316 static size_t
1317 arena_decay_npages_limit(arena_t *arena)
1318 {
1319 	size_t npages_limit;
1320 
1321 	assert(opt_purge == purge_mode_decay);
1322 
1323 	npages_limit = arena->decay_backlog_npages_limit;
1324 
1325 	/* Add in any dirty pages created during the current epoch. */
1326 	if (arena->ndirty > arena->decay_ndirty)
1327 		npages_limit += arena->ndirty - arena->decay_ndirty;
1328 
1329 	return (npages_limit);
1330 }
1331 
1332 static void
1333 arena_decay_init(arena_t *arena, ssize_t decay_time)
1334 {
1335 
1336 	arena->decay_time = decay_time;
1337 	if (decay_time > 0) {
1338 		nstime_init2(&arena->decay_interval, decay_time, 0);
1339 		nstime_idivide(&arena->decay_interval, SMOOTHSTEP_NSTEPS);
1340 	}
1341 
1342 	nstime_init(&arena->decay_epoch, 0);
1343 	nstime_update(&arena->decay_epoch);
1344 	arena->decay_jitter_state = (uint64_t)(uintptr_t)arena;
1345 	arena_decay_deadline_init(arena);
1346 	arena->decay_ndirty = arena->ndirty;
1347 	arena->decay_backlog_npages_limit = 0;
1348 	memset(arena->decay_backlog, 0, SMOOTHSTEP_NSTEPS * sizeof(size_t));
1349 }
1350 
1351 static bool
1352 arena_decay_time_valid(ssize_t decay_time)
1353 {
1354 
1355 	if (decay_time < -1)
1356 		return (false);
1357 	if (decay_time == -1 || (uint64_t)decay_time <= NSTIME_SEC_MAX)
1358 		return (true);
1359 	return (false);
1360 }
1361 
1362 ssize_t
1363 arena_decay_time_get(arena_t *arena)
1364 {
1365 	ssize_t decay_time;
1366 
1367 	malloc_mutex_lock(&arena->lock);
1368 	decay_time = arena->decay_time;
1369 	malloc_mutex_unlock(&arena->lock);
1370 
1371 	return (decay_time);
1372 }
1373 
1374 bool
1375 arena_decay_time_set(arena_t *arena, ssize_t decay_time)
1376 {
1377 
1378 	if (!arena_decay_time_valid(decay_time))
1379 		return (true);
1380 
1381 	malloc_mutex_lock(&arena->lock);
1382 	/*
1383 	 * Restart decay backlog from scratch, which may cause many dirty pages
1384 	 * to be immediately purged.  It would conceptually be possible to map
1385 	 * the old backlog onto the new backlog, but there is no justification
1386 	 * for such complexity since decay_time changes are intended to be
1387 	 * infrequent, either between the {-1, 0, >0} states, or a one-time
1388 	 * arbitrary change during initial arena configuration.
1389 	 */
1390 	arena_decay_init(arena, decay_time);
1391 	arena_maybe_purge(arena);
1392 	malloc_mutex_unlock(&arena->lock);
1393 
1394 	return (false);
1395 }
1396 
1397 static void
1398 arena_maybe_purge_ratio(arena_t *arena)
1399 {
1400 
1401 	assert(opt_purge == purge_mode_ratio);
1402 
1403 	/* Don't purge if the option is disabled. */
1404 	if (arena->lg_dirty_mult < 0)
1405 		return;
1406 
1407 	/*
1408 	 * Iterate, since preventing recursive purging could otherwise leave too
1409 	 * many dirty pages.
1410 	 */
1411 	while (true) {
1412 		size_t threshold = (arena->nactive >> arena->lg_dirty_mult);
1413 		if (threshold < chunk_npages)
1414 			threshold = chunk_npages;
1415 		/*
1416 		 * Don't purge unless the number of purgeable pages exceeds the
1417 		 * threshold.
1418 		 */
1419 		if (arena->ndirty <= threshold)
1420 			return;
1421 		arena_purge_to_limit(arena, threshold);
1422 	}
1423 }
1424 
1425 static void
1426 arena_maybe_purge_decay(arena_t *arena)
1427 {
1428 	nstime_t time;
1429 	size_t ndirty_limit;
1430 
1431 	assert(opt_purge == purge_mode_decay);
1432 
1433 	/* Purge all or nothing if the option is disabled. */
1434 	if (arena->decay_time <= 0) {
1435 		if (arena->decay_time == 0)
1436 			arena_purge_to_limit(arena, 0);
1437 		return;
1438 	}
1439 
1440 	nstime_copy(&time, &arena->decay_epoch);
1441 	if (unlikely(nstime_update(&time))) {
1442 		/* Time went backwards.  Force an epoch advance. */
1443 		nstime_copy(&time, &arena->decay_deadline);
1444 	}
1445 
1446 	if (arena_decay_deadline_reached(arena, &time))
1447 		arena_decay_epoch_advance(arena, &time);
1448 
1449 	ndirty_limit = arena_decay_npages_limit(arena);
1450 
1451 	/*
1452 	 * Don't try to purge unless the number of purgeable pages exceeds the
1453 	 * current limit.
1454 	 */
1455 	if (arena->ndirty <= ndirty_limit)
1456 		return;
1457 	arena_purge_to_limit(arena, ndirty_limit);
1458 }
1459 
1460 void
1461 arena_maybe_purge(arena_t *arena)
1462 {
1463 
1464 	/* Don't recursively purge. */
1465 	if (arena->purging)
1466 		return;
1467 
1468 	if (opt_purge == purge_mode_ratio)
1469 		arena_maybe_purge_ratio(arena);
1470 	else
1471 		arena_maybe_purge_decay(arena);
1472 }
1473 
1474 static size_t
1475 arena_dirty_count(arena_t *arena)
1476 {
1477 	size_t ndirty = 0;
1478 	arena_runs_dirty_link_t *rdelm;
1479 	extent_node_t *chunkselm;
1480 
1481 	for (rdelm = qr_next(&arena->runs_dirty, rd_link),
1482 	    chunkselm = qr_next(&arena->chunks_cache, cc_link);
1483 	    rdelm != &arena->runs_dirty; rdelm = qr_next(rdelm, rd_link)) {
1484 		size_t npages;
1485 
1486 		if (rdelm == &chunkselm->rd) {
1487 			npages = extent_node_size_get(chunkselm) >> LG_PAGE;
1488 			chunkselm = qr_next(chunkselm, cc_link);
1489 		} else {
1490 			arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(
1491 			    rdelm);
1492 			arena_chunk_map_misc_t *miscelm =
1493 			    arena_rd_to_miscelm(rdelm);
1494 			size_t pageind = arena_miscelm_to_pageind(miscelm);
1495 			assert(arena_mapbits_allocated_get(chunk, pageind) ==
1496 			    0);
1497 			assert(arena_mapbits_large_get(chunk, pageind) == 0);
1498 			assert(arena_mapbits_dirty_get(chunk, pageind) != 0);
1499 			npages = arena_mapbits_unallocated_size_get(chunk,
1500 			    pageind) >> LG_PAGE;
1501 		}
1502 		ndirty += npages;
1503 	}
1504 
1505 	return (ndirty);
1506 }
1507 
1508 static size_t
1509 arena_stash_dirty(arena_t *arena, chunk_hooks_t *chunk_hooks,
1510     size_t ndirty_limit, arena_runs_dirty_link_t *purge_runs_sentinel,
1511     extent_node_t *purge_chunks_sentinel)
1512 {
1513 	arena_runs_dirty_link_t *rdelm, *rdelm_next;
1514 	extent_node_t *chunkselm;
1515 	size_t nstashed = 0;
1516 
1517 	/* Stash runs/chunks according to ndirty_limit. */
1518 	for (rdelm = qr_next(&arena->runs_dirty, rd_link),
1519 	    chunkselm = qr_next(&arena->chunks_cache, cc_link);
1520 	    rdelm != &arena->runs_dirty; rdelm = rdelm_next) {
1521 		size_t npages;
1522 		rdelm_next = qr_next(rdelm, rd_link);
1523 
1524 		if (rdelm == &chunkselm->rd) {
1525 			extent_node_t *chunkselm_next;
1526 			bool zero;
1527 			UNUSED void *chunk;
1528 
1529 			npages = extent_node_size_get(chunkselm) >> LG_PAGE;
1530 			if (opt_purge == purge_mode_decay && arena->ndirty -
1531 			    (nstashed + npages) < ndirty_limit)
1532 				break;
1533 
1534 			chunkselm_next = qr_next(chunkselm, cc_link);
1535 			/*
1536 			 * Allocate.  chunkselm remains valid due to the
1537 			 * dalloc_node=false argument to chunk_alloc_cache().
1538 			 */
1539 			zero = false;
1540 			chunk = chunk_alloc_cache(arena, chunk_hooks,
1541 			    extent_node_addr_get(chunkselm),
1542 			    extent_node_size_get(chunkselm), chunksize, &zero,
1543 			    false);
1544 			assert(chunk == extent_node_addr_get(chunkselm));
1545 			assert(zero == extent_node_zeroed_get(chunkselm));
1546 			extent_node_dirty_insert(chunkselm, purge_runs_sentinel,
1547 			    purge_chunks_sentinel);
1548 			assert(npages == (extent_node_size_get(chunkselm) >>
1549 			    LG_PAGE));
1550 			chunkselm = chunkselm_next;
1551 		} else {
1552 			arena_chunk_t *chunk =
1553 			    (arena_chunk_t *)CHUNK_ADDR2BASE(rdelm);
1554 			arena_chunk_map_misc_t *miscelm =
1555 			    arena_rd_to_miscelm(rdelm);
1556 			size_t pageind = arena_miscelm_to_pageind(miscelm);
1557 			arena_run_t *run = &miscelm->run;
1558 			size_t run_size =
1559 			    arena_mapbits_unallocated_size_get(chunk, pageind);
1560 
1561 			npages = run_size >> LG_PAGE;
1562 			if (opt_purge == purge_mode_decay && arena->ndirty -
1563 			    (nstashed + npages) < ndirty_limit)
1564 				break;
1565 
1566 			assert(pageind + npages <= chunk_npages);
1567 			assert(arena_mapbits_dirty_get(chunk, pageind) ==
1568 			    arena_mapbits_dirty_get(chunk, pageind+npages-1));
1569 
1570 			/*
1571 			 * If purging the spare chunk's run, make it available
1572 			 * prior to allocation.
1573 			 */
1574 			if (chunk == arena->spare)
1575 				arena_chunk_alloc(arena);
1576 
1577 			/* Temporarily allocate the free dirty run. */
1578 			arena_run_split_large(arena, run, run_size, false);
1579 			/* Stash. */
1580 			if (false)
1581 				qr_new(rdelm, rd_link); /* Redundant. */
1582 			else {
1583 				assert(qr_next(rdelm, rd_link) == rdelm);
1584 				assert(qr_prev(rdelm, rd_link) == rdelm);
1585 			}
1586 			qr_meld(purge_runs_sentinel, rdelm, rd_link);
1587 		}
1588 
1589 		nstashed += npages;
1590 		if (opt_purge == purge_mode_ratio && arena->ndirty - nstashed <=
1591 		    ndirty_limit)
1592 			break;
1593 	}
1594 
1595 	return (nstashed);
1596 }
1597 
1598 static size_t
1599 arena_purge_stashed(arena_t *arena, chunk_hooks_t *chunk_hooks,
1600     arena_runs_dirty_link_t *purge_runs_sentinel,
1601     extent_node_t *purge_chunks_sentinel)
1602 {
1603 	size_t npurged, nmadvise;
1604 	arena_runs_dirty_link_t *rdelm;
1605 	extent_node_t *chunkselm;
1606 
1607 	if (config_stats)
1608 		nmadvise = 0;
1609 	npurged = 0;
1610 
1611 	malloc_mutex_unlock(&arena->lock);
1612 	for (rdelm = qr_next(purge_runs_sentinel, rd_link),
1613 	    chunkselm = qr_next(purge_chunks_sentinel, cc_link);
1614 	    rdelm != purge_runs_sentinel; rdelm = qr_next(rdelm, rd_link)) {
1615 		size_t npages;
1616 
1617 		if (rdelm == &chunkselm->rd) {
1618 			/*
1619 			 * Don't actually purge the chunk here because 1)
1620 			 * chunkselm is embedded in the chunk and must remain
1621 			 * valid, and 2) we deallocate the chunk in
1622 			 * arena_unstash_purged(), where it is destroyed,
1623 			 * decommitted, or purged, depending on chunk
1624 			 * deallocation policy.
1625 			 */
1626 			size_t size = extent_node_size_get(chunkselm);
1627 			npages = size >> LG_PAGE;
1628 			chunkselm = qr_next(chunkselm, cc_link);
1629 		} else {
1630 			size_t pageind, run_size, flag_unzeroed, flags, i;
1631 			bool decommitted;
1632 			arena_chunk_t *chunk =
1633 			    (arena_chunk_t *)CHUNK_ADDR2BASE(rdelm);
1634 			arena_chunk_map_misc_t *miscelm =
1635 			    arena_rd_to_miscelm(rdelm);
1636 			pageind = arena_miscelm_to_pageind(miscelm);
1637 			run_size = arena_mapbits_large_size_get(chunk, pageind);
1638 			npages = run_size >> LG_PAGE;
1639 
1640 			assert(pageind + npages <= chunk_npages);
1641 			assert(!arena_mapbits_decommitted_get(chunk, pageind));
1642 			assert(!arena_mapbits_decommitted_get(chunk,
1643 			    pageind+npages-1));
1644 			decommitted = !chunk_hooks->decommit(chunk, chunksize,
1645 			    pageind << LG_PAGE, npages << LG_PAGE, arena->ind);
1646 			if (decommitted) {
1647 				flag_unzeroed = 0;
1648 				flags = CHUNK_MAP_DECOMMITTED;
1649 			} else {
1650 				flag_unzeroed = chunk_purge_wrapper(arena,
1651 				    chunk_hooks, chunk, chunksize, pageind <<
1652 				    LG_PAGE, run_size) ? CHUNK_MAP_UNZEROED : 0;
1653 				flags = flag_unzeroed;
1654 			}
1655 			arena_mapbits_large_set(chunk, pageind+npages-1, 0,
1656 			    flags);
1657 			arena_mapbits_large_set(chunk, pageind, run_size,
1658 			    flags);
1659 
1660 			/*
1661 			 * Set the unzeroed flag for internal pages, now that
1662 			 * chunk_purge_wrapper() has returned whether the pages
1663 			 * were zeroed as a side effect of purging.  This chunk
1664 			 * map modification is safe even though the arena mutex
1665 			 * isn't currently owned by this thread, because the run
1666 			 * is marked as allocated, thus protecting it from being
1667 			 * modified by any other thread.  As long as these
1668 			 * writes don't perturb the first and last elements'
1669 			 * CHUNK_MAP_ALLOCATED bits, behavior is well defined.
1670 			 */
1671 			for (i = 1; i < npages-1; i++) {
1672 				arena_mapbits_internal_set(chunk, pageind+i,
1673 				    flag_unzeroed);
1674 			}
1675 		}
1676 
1677 		npurged += npages;
1678 		if (config_stats)
1679 			nmadvise++;
1680 	}
1681 	malloc_mutex_lock(&arena->lock);
1682 
1683 	if (config_stats) {
1684 		arena->stats.nmadvise += nmadvise;
1685 		arena->stats.purged += npurged;
1686 	}
1687 
1688 	return (npurged);
1689 }
1690 
1691 static void
1692 arena_unstash_purged(arena_t *arena, chunk_hooks_t *chunk_hooks,
1693     arena_runs_dirty_link_t *purge_runs_sentinel,
1694     extent_node_t *purge_chunks_sentinel)
1695 {
1696 	arena_runs_dirty_link_t *rdelm, *rdelm_next;
1697 	extent_node_t *chunkselm;
1698 
1699 	/* Deallocate chunks/runs. */
1700 	for (rdelm = qr_next(purge_runs_sentinel, rd_link),
1701 	    chunkselm = qr_next(purge_chunks_sentinel, cc_link);
1702 	    rdelm != purge_runs_sentinel; rdelm = rdelm_next) {
1703 		rdelm_next = qr_next(rdelm, rd_link);
1704 		if (rdelm == &chunkselm->rd) {
1705 			extent_node_t *chunkselm_next = qr_next(chunkselm,
1706 			    cc_link);
1707 			void *addr = extent_node_addr_get(chunkselm);
1708 			size_t size = extent_node_size_get(chunkselm);
1709 			bool zeroed = extent_node_zeroed_get(chunkselm);
1710 			bool committed = extent_node_committed_get(chunkselm);
1711 			extent_node_dirty_remove(chunkselm);
1712 			arena_node_dalloc(arena, chunkselm);
1713 			chunkselm = chunkselm_next;
1714 			chunk_dalloc_arena(arena, chunk_hooks, addr, size,
1715 			    zeroed, committed);
1716 		} else {
1717 			arena_chunk_t *chunk =
1718 			    (arena_chunk_t *)CHUNK_ADDR2BASE(rdelm);
1719 			arena_chunk_map_misc_t *miscelm =
1720 			    arena_rd_to_miscelm(rdelm);
1721 			size_t pageind = arena_miscelm_to_pageind(miscelm);
1722 			bool decommitted = (arena_mapbits_decommitted_get(chunk,
1723 			    pageind) != 0);
1724 			arena_run_t *run = &miscelm->run;
1725 			qr_remove(rdelm, rd_link);
1726 			arena_run_dalloc(arena, run, false, true, decommitted);
1727 		}
1728 	}
1729 }
1730 
1731 /*
1732  * NB: ndirty_limit is interpreted differently depending on opt_purge:
1733  *   - purge_mode_ratio: Purge as few dirty run/chunks as possible to reach the
1734  *                       desired state:
1735  *                       (arena->ndirty <= ndirty_limit)
1736  *   - purge_mode_decay: Purge as many dirty runs/chunks as possible without
1737  *                       violating the invariant:
1738  *                       (arena->ndirty >= ndirty_limit)
1739  */
1740 static void
1741 arena_purge_to_limit(arena_t *arena, size_t ndirty_limit)
1742 {
1743 	chunk_hooks_t chunk_hooks = chunk_hooks_get(arena);
1744 	size_t npurge, npurged;
1745 	arena_runs_dirty_link_t purge_runs_sentinel;
1746 	extent_node_t purge_chunks_sentinel;
1747 
1748 	arena->purging = true;
1749 
1750 	/*
1751 	 * Calls to arena_dirty_count() are disabled even for debug builds
1752 	 * because overhead grows nonlinearly as memory usage increases.
1753 	 */
1754 	if (false && config_debug) {
1755 		size_t ndirty = arena_dirty_count(arena);
1756 		assert(ndirty == arena->ndirty);
1757 	}
1758 	assert(opt_purge != purge_mode_ratio || (arena->nactive >>
1759 	    arena->lg_dirty_mult) < arena->ndirty || ndirty_limit == 0);
1760 
1761 	qr_new(&purge_runs_sentinel, rd_link);
1762 	extent_node_dirty_linkage_init(&purge_chunks_sentinel);
1763 
1764 	npurge = arena_stash_dirty(arena, &chunk_hooks, ndirty_limit,
1765 	    &purge_runs_sentinel, &purge_chunks_sentinel);
1766 	if (npurge == 0)
1767 		goto label_return;
1768 	npurged = arena_purge_stashed(arena, &chunk_hooks, &purge_runs_sentinel,
1769 	    &purge_chunks_sentinel);
1770 	assert(npurged == npurge);
1771 	arena_unstash_purged(arena, &chunk_hooks, &purge_runs_sentinel,
1772 	    &purge_chunks_sentinel);
1773 
1774 	if (config_stats)
1775 		arena->stats.npurge++;
1776 
1777 label_return:
1778 	arena->purging = false;
1779 }
1780 
1781 void
1782 arena_purge(arena_t *arena, bool all)
1783 {
1784 
1785 	malloc_mutex_lock(&arena->lock);
1786 	if (all)
1787 		arena_purge_to_limit(arena, 0);
1788 	else
1789 		arena_maybe_purge(arena);
1790 	malloc_mutex_unlock(&arena->lock);
1791 }
1792 
1793 static void
1794 arena_run_coalesce(arena_t *arena, arena_chunk_t *chunk, size_t *p_size,
1795     size_t *p_run_ind, size_t *p_run_pages, size_t flag_dirty,
1796     size_t flag_decommitted)
1797 {
1798 	size_t size = *p_size;
1799 	size_t run_ind = *p_run_ind;
1800 	size_t run_pages = *p_run_pages;
1801 
1802 	/* Try to coalesce forward. */
1803 	if (run_ind + run_pages < chunk_npages &&
1804 	    arena_mapbits_allocated_get(chunk, run_ind+run_pages) == 0 &&
1805 	    arena_mapbits_dirty_get(chunk, run_ind+run_pages) == flag_dirty &&
1806 	    arena_mapbits_decommitted_get(chunk, run_ind+run_pages) ==
1807 	    flag_decommitted) {
1808 		size_t nrun_size = arena_mapbits_unallocated_size_get(chunk,
1809 		    run_ind+run_pages);
1810 		size_t nrun_pages = nrun_size >> LG_PAGE;
1811 
1812 		/*
1813 		 * Remove successor from runs_avail; the coalesced run is
1814 		 * inserted later.
1815 		 */
1816 		assert(arena_mapbits_unallocated_size_get(chunk,
1817 		    run_ind+run_pages+nrun_pages-1) == nrun_size);
1818 		assert(arena_mapbits_dirty_get(chunk,
1819 		    run_ind+run_pages+nrun_pages-1) == flag_dirty);
1820 		assert(arena_mapbits_decommitted_get(chunk,
1821 		    run_ind+run_pages+nrun_pages-1) == flag_decommitted);
1822 		arena_avail_remove(arena, chunk, run_ind+run_pages, nrun_pages);
1823 
1824 		/*
1825 		 * If the successor is dirty, remove it from the set of dirty
1826 		 * pages.
1827 		 */
1828 		if (flag_dirty != 0) {
1829 			arena_run_dirty_remove(arena, chunk, run_ind+run_pages,
1830 			    nrun_pages);
1831 		}
1832 
1833 		size += nrun_size;
1834 		run_pages += nrun_pages;
1835 
1836 		arena_mapbits_unallocated_size_set(chunk, run_ind, size);
1837 		arena_mapbits_unallocated_size_set(chunk, run_ind+run_pages-1,
1838 		    size);
1839 	}
1840 
1841 	/* Try to coalesce backward. */
1842 	if (run_ind > map_bias && arena_mapbits_allocated_get(chunk,
1843 	    run_ind-1) == 0 && arena_mapbits_dirty_get(chunk, run_ind-1) ==
1844 	    flag_dirty && arena_mapbits_decommitted_get(chunk, run_ind-1) ==
1845 	    flag_decommitted) {
1846 		size_t prun_size = arena_mapbits_unallocated_size_get(chunk,
1847 		    run_ind-1);
1848 		size_t prun_pages = prun_size >> LG_PAGE;
1849 
1850 		run_ind -= prun_pages;
1851 
1852 		/*
1853 		 * Remove predecessor from runs_avail; the coalesced run is
1854 		 * inserted later.
1855 		 */
1856 		assert(arena_mapbits_unallocated_size_get(chunk, run_ind) ==
1857 		    prun_size);
1858 		assert(arena_mapbits_dirty_get(chunk, run_ind) == flag_dirty);
1859 		assert(arena_mapbits_decommitted_get(chunk, run_ind) ==
1860 		    flag_decommitted);
1861 		arena_avail_remove(arena, chunk, run_ind, prun_pages);
1862 
1863 		/*
1864 		 * If the predecessor is dirty, remove it from the set of dirty
1865 		 * pages.
1866 		 */
1867 		if (flag_dirty != 0) {
1868 			arena_run_dirty_remove(arena, chunk, run_ind,
1869 			    prun_pages);
1870 		}
1871 
1872 		size += prun_size;
1873 		run_pages += prun_pages;
1874 
1875 		arena_mapbits_unallocated_size_set(chunk, run_ind, size);
1876 		arena_mapbits_unallocated_size_set(chunk, run_ind+run_pages-1,
1877 		    size);
1878 	}
1879 
1880 	*p_size = size;
1881 	*p_run_ind = run_ind;
1882 	*p_run_pages = run_pages;
1883 }
1884 
1885 static size_t
1886 arena_run_size_get(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
1887     size_t run_ind)
1888 {
1889 	size_t size;
1890 
1891 	assert(run_ind >= map_bias);
1892 	assert(run_ind < chunk_npages);
1893 
1894 	if (arena_mapbits_large_get(chunk, run_ind) != 0) {
1895 		size = arena_mapbits_large_size_get(chunk, run_ind);
1896 		assert(size == PAGE || arena_mapbits_large_size_get(chunk,
1897 		    run_ind+(size>>LG_PAGE)-1) == 0);
1898 	} else {
1899 		arena_bin_info_t *bin_info = &arena_bin_info[run->binind];
1900 		size = bin_info->run_size;
1901 	}
1902 
1903 	return (size);
1904 }
1905 
1906 static void
1907 arena_run_dalloc(arena_t *arena, arena_run_t *run, bool dirty, bool cleaned,
1908     bool decommitted)
1909 {
1910 	arena_chunk_t *chunk;
1911 	arena_chunk_map_misc_t *miscelm;
1912 	size_t size, run_ind, run_pages, flag_dirty, flag_decommitted;
1913 
1914 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
1915 	miscelm = arena_run_to_miscelm(run);
1916 	run_ind = arena_miscelm_to_pageind(miscelm);
1917 	assert(run_ind >= map_bias);
1918 	assert(run_ind < chunk_npages);
1919 	size = arena_run_size_get(arena, chunk, run, run_ind);
1920 	run_pages = (size >> LG_PAGE);
1921 	arena_nactive_sub(arena, run_pages);
1922 
1923 	/*
1924 	 * The run is dirty if the caller claims to have dirtied it, as well as
1925 	 * if it was already dirty before being allocated and the caller
1926 	 * doesn't claim to have cleaned it.
1927 	 */
1928 	assert(arena_mapbits_dirty_get(chunk, run_ind) ==
1929 	    arena_mapbits_dirty_get(chunk, run_ind+run_pages-1));
1930 	if (!cleaned && !decommitted && arena_mapbits_dirty_get(chunk, run_ind)
1931 	    != 0)
1932 		dirty = true;
1933 	flag_dirty = dirty ? CHUNK_MAP_DIRTY : 0;
1934 	flag_decommitted = decommitted ? CHUNK_MAP_DECOMMITTED : 0;
1935 
1936 	/* Mark pages as unallocated in the chunk map. */
1937 	if (dirty || decommitted) {
1938 		size_t flags = flag_dirty | flag_decommitted;
1939 		arena_mapbits_unallocated_set(chunk, run_ind, size, flags);
1940 		arena_mapbits_unallocated_set(chunk, run_ind+run_pages-1, size,
1941 		    flags);
1942 	} else {
1943 		arena_mapbits_unallocated_set(chunk, run_ind, size,
1944 		    arena_mapbits_unzeroed_get(chunk, run_ind));
1945 		arena_mapbits_unallocated_set(chunk, run_ind+run_pages-1, size,
1946 		    arena_mapbits_unzeroed_get(chunk, run_ind+run_pages-1));
1947 	}
1948 
1949 	arena_run_coalesce(arena, chunk, &size, &run_ind, &run_pages,
1950 	    flag_dirty, flag_decommitted);
1951 
1952 	/* Insert into runs_avail, now that coalescing is complete. */
1953 	assert(arena_mapbits_unallocated_size_get(chunk, run_ind) ==
1954 	    arena_mapbits_unallocated_size_get(chunk, run_ind+run_pages-1));
1955 	assert(arena_mapbits_dirty_get(chunk, run_ind) ==
1956 	    arena_mapbits_dirty_get(chunk, run_ind+run_pages-1));
1957 	assert(arena_mapbits_decommitted_get(chunk, run_ind) ==
1958 	    arena_mapbits_decommitted_get(chunk, run_ind+run_pages-1));
1959 	arena_avail_insert(arena, chunk, run_ind, run_pages);
1960 
1961 	if (dirty)
1962 		arena_run_dirty_insert(arena, chunk, run_ind, run_pages);
1963 
1964 	/* Deallocate chunk if it is now completely unused. */
1965 	if (size == arena_maxrun) {
1966 		assert(run_ind == map_bias);
1967 		assert(run_pages == (arena_maxrun >> LG_PAGE));
1968 		arena_chunk_dalloc(arena, chunk);
1969 	}
1970 
1971 	/*
1972 	 * It is okay to do dirty page processing here even if the chunk was
1973 	 * deallocated above, since in that case it is the spare.  Waiting
1974 	 * until after possible chunk deallocation to do dirty processing
1975 	 * allows for an old spare to be fully deallocated, thus decreasing the
1976 	 * chances of spuriously crossing the dirty page purging threshold.
1977 	 */
1978 	if (dirty)
1979 		arena_maybe_purge(arena);
1980 }
1981 
1982 static void
1983 arena_run_trim_head(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
1984     size_t oldsize, size_t newsize)
1985 {
1986 	arena_chunk_map_misc_t *miscelm = arena_run_to_miscelm(run);
1987 	size_t pageind = arena_miscelm_to_pageind(miscelm);
1988 	size_t head_npages = (oldsize - newsize) >> LG_PAGE;
1989 	size_t flag_dirty = arena_mapbits_dirty_get(chunk, pageind);
1990 	size_t flag_decommitted = arena_mapbits_decommitted_get(chunk, pageind);
1991 	size_t flag_unzeroed_mask = (flag_dirty | flag_decommitted) == 0 ?
1992 	    CHUNK_MAP_UNZEROED : 0;
1993 
1994 	assert(oldsize > newsize);
1995 
1996 	/*
1997 	 * Update the chunk map so that arena_run_dalloc() can treat the
1998 	 * leading run as separately allocated.  Set the last element of each
1999 	 * run first, in case of single-page runs.
2000 	 */
2001 	assert(arena_mapbits_large_size_get(chunk, pageind) == oldsize);
2002 	arena_mapbits_large_set(chunk, pageind+head_npages-1, 0, flag_dirty |
2003 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
2004 	    pageind+head_npages-1)));
2005 	arena_mapbits_large_set(chunk, pageind, oldsize-newsize, flag_dirty |
2006 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk, pageind)));
2007 
2008 	if (config_debug) {
2009 		UNUSED size_t tail_npages = newsize >> LG_PAGE;
2010 		assert(arena_mapbits_large_size_get(chunk,
2011 		    pageind+head_npages+tail_npages-1) == 0);
2012 		assert(arena_mapbits_dirty_get(chunk,
2013 		    pageind+head_npages+tail_npages-1) == flag_dirty);
2014 	}
2015 	arena_mapbits_large_set(chunk, pageind+head_npages, newsize,
2016 	    flag_dirty | (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
2017 	    pageind+head_npages)));
2018 
2019 	arena_run_dalloc(arena, run, false, false, (flag_decommitted != 0));
2020 }
2021 
2022 static void
2023 arena_run_trim_tail(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
2024     size_t oldsize, size_t newsize, bool dirty)
2025 {
2026 	arena_chunk_map_misc_t *miscelm = arena_run_to_miscelm(run);
2027 	size_t pageind = arena_miscelm_to_pageind(miscelm);
2028 	size_t head_npages = newsize >> LG_PAGE;
2029 	size_t flag_dirty = arena_mapbits_dirty_get(chunk, pageind);
2030 	size_t flag_decommitted = arena_mapbits_decommitted_get(chunk, pageind);
2031 	size_t flag_unzeroed_mask = (flag_dirty | flag_decommitted) == 0 ?
2032 	    CHUNK_MAP_UNZEROED : 0;
2033 	arena_chunk_map_misc_t *tail_miscelm;
2034 	arena_run_t *tail_run;
2035 
2036 	assert(oldsize > newsize);
2037 
2038 	/*
2039 	 * Update the chunk map so that arena_run_dalloc() can treat the
2040 	 * trailing run as separately allocated.  Set the last element of each
2041 	 * run first, in case of single-page runs.
2042 	 */
2043 	assert(arena_mapbits_large_size_get(chunk, pageind) == oldsize);
2044 	arena_mapbits_large_set(chunk, pageind+head_npages-1, 0, flag_dirty |
2045 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
2046 	    pageind+head_npages-1)));
2047 	arena_mapbits_large_set(chunk, pageind, newsize, flag_dirty |
2048 	    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk, pageind)));
2049 
2050 	if (config_debug) {
2051 		UNUSED size_t tail_npages = (oldsize - newsize) >> LG_PAGE;
2052 		assert(arena_mapbits_large_size_get(chunk,
2053 		    pageind+head_npages+tail_npages-1) == 0);
2054 		assert(arena_mapbits_dirty_get(chunk,
2055 		    pageind+head_npages+tail_npages-1) == flag_dirty);
2056 	}
2057 	arena_mapbits_large_set(chunk, pageind+head_npages, oldsize-newsize,
2058 	    flag_dirty | (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
2059 	    pageind+head_npages)));
2060 
2061 	tail_miscelm = arena_miscelm_get(chunk, pageind + head_npages);
2062 	tail_run = &tail_miscelm->run;
2063 	arena_run_dalloc(arena, tail_run, dirty, false, (flag_decommitted !=
2064 	    0));
2065 }
2066 
2067 static arena_run_t *
2068 arena_bin_runs_first(arena_bin_t *bin)
2069 {
2070 	arena_chunk_map_misc_t *miscelm = arena_run_tree_first(&bin->runs);
2071 	if (miscelm != NULL)
2072 		return (&miscelm->run);
2073 
2074 	return (NULL);
2075 }
2076 
2077 static void
2078 arena_bin_runs_insert(arena_bin_t *bin, arena_run_t *run)
2079 {
2080 	arena_chunk_map_misc_t *miscelm = arena_run_to_miscelm(run);
2081 
2082 	assert(arena_run_tree_search(&bin->runs, miscelm) == NULL);
2083 
2084 	arena_run_tree_insert(&bin->runs, miscelm);
2085 }
2086 
2087 static void
2088 arena_bin_runs_remove(arena_bin_t *bin, arena_run_t *run)
2089 {
2090 	arena_chunk_map_misc_t *miscelm = arena_run_to_miscelm(run);
2091 
2092 	assert(arena_run_tree_search(&bin->runs, miscelm) != NULL);
2093 
2094 	arena_run_tree_remove(&bin->runs, miscelm);
2095 }
2096 
2097 static arena_run_t *
2098 arena_bin_nonfull_run_tryget(arena_bin_t *bin)
2099 {
2100 	arena_run_t *run = arena_bin_runs_first(bin);
2101 	if (run != NULL) {
2102 		arena_bin_runs_remove(bin, run);
2103 		if (config_stats)
2104 			bin->stats.reruns++;
2105 	}
2106 	return (run);
2107 }
2108 
2109 static arena_run_t *
2110 arena_bin_nonfull_run_get(arena_t *arena, arena_bin_t *bin)
2111 {
2112 	arena_run_t *run;
2113 	szind_t binind;
2114 	arena_bin_info_t *bin_info;
2115 
2116 	/* Look for a usable run. */
2117 	run = arena_bin_nonfull_run_tryget(bin);
2118 	if (run != NULL)
2119 		return (run);
2120 	/* No existing runs have any space available. */
2121 
2122 	binind = arena_bin_index(arena, bin);
2123 	bin_info = &arena_bin_info[binind];
2124 
2125 	/* Allocate a new run. */
2126 	malloc_mutex_unlock(&bin->lock);
2127 	/******************************/
2128 	malloc_mutex_lock(&arena->lock);
2129 	run = arena_run_alloc_small(arena, bin_info->run_size, binind);
2130 	if (run != NULL) {
2131 		/* Initialize run internals. */
2132 		run->binind = binind;
2133 		run->nfree = bin_info->nregs;
2134 		bitmap_init(run->bitmap, &bin_info->bitmap_info);
2135 	}
2136 	malloc_mutex_unlock(&arena->lock);
2137 	/********************************/
2138 	malloc_mutex_lock(&bin->lock);
2139 	if (run != NULL) {
2140 		if (config_stats) {
2141 			bin->stats.nruns++;
2142 			bin->stats.curruns++;
2143 		}
2144 		return (run);
2145 	}
2146 
2147 	/*
2148 	 * arena_run_alloc_small() failed, but another thread may have made
2149 	 * sufficient memory available while this one dropped bin->lock above,
2150 	 * so search one more time.
2151 	 */
2152 	run = arena_bin_nonfull_run_tryget(bin);
2153 	if (run != NULL)
2154 		return (run);
2155 
2156 	return (NULL);
2157 }
2158 
2159 /* Re-fill bin->runcur, then call arena_run_reg_alloc(). */
2160 static void *
2161 arena_bin_malloc_hard(arena_t *arena, arena_bin_t *bin)
2162 {
2163 	szind_t binind;
2164 	arena_bin_info_t *bin_info;
2165 	arena_run_t *run;
2166 
2167 	binind = arena_bin_index(arena, bin);
2168 	bin_info = &arena_bin_info[binind];
2169 	bin->runcur = NULL;
2170 	run = arena_bin_nonfull_run_get(arena, bin);
2171 	if (bin->runcur != NULL && bin->runcur->nfree > 0) {
2172 		/*
2173 		 * Another thread updated runcur while this one ran without the
2174 		 * bin lock in arena_bin_nonfull_run_get().
2175 		 */
2176 		void *ret;
2177 		assert(bin->runcur->nfree > 0);
2178 		ret = arena_run_reg_alloc(bin->runcur, bin_info);
2179 		if (run != NULL) {
2180 			arena_chunk_t *chunk;
2181 
2182 			/*
2183 			 * arena_run_alloc_small() may have allocated run, or
2184 			 * it may have pulled run from the bin's run tree.
2185 			 * Therefore it is unsafe to make any assumptions about
2186 			 * how run has previously been used, and
2187 			 * arena_bin_lower_run() must be called, as if a region
2188 			 * were just deallocated from the run.
2189 			 */
2190 			chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
2191 			if (run->nfree == bin_info->nregs)
2192 				arena_dalloc_bin_run(arena, chunk, run, bin);
2193 			else
2194 				arena_bin_lower_run(arena, chunk, run, bin);
2195 		}
2196 		return (ret);
2197 	}
2198 
2199 	if (run == NULL)
2200 		return (NULL);
2201 
2202 	bin->runcur = run;
2203 
2204 	assert(bin->runcur->nfree > 0);
2205 
2206 	return (arena_run_reg_alloc(bin->runcur, bin_info));
2207 }
2208 
2209 void
2210 arena_tcache_fill_small(tsd_t *tsd, arena_t *arena, tcache_bin_t *tbin,
2211     szind_t binind, uint64_t prof_accumbytes)
2212 {
2213 	unsigned i, nfill;
2214 	arena_bin_t *bin;
2215 
2216 	assert(tbin->ncached == 0);
2217 
2218 	if (config_prof && arena_prof_accum(arena, prof_accumbytes))
2219 		prof_idump();
2220 	bin = &arena->bins[binind];
2221 	malloc_mutex_lock(&bin->lock);
2222 	for (i = 0, nfill = (tcache_bin_info[binind].ncached_max >>
2223 	    tbin->lg_fill_div); i < nfill; i++) {
2224 		arena_run_t *run;
2225 		void *ptr;
2226 		if ((run = bin->runcur) != NULL && run->nfree > 0)
2227 			ptr = arena_run_reg_alloc(run, &arena_bin_info[binind]);
2228 		else
2229 			ptr = arena_bin_malloc_hard(arena, bin);
2230 		if (ptr == NULL) {
2231 			/*
2232 			 * OOM.  tbin->avail isn't yet filled down to its first
2233 			 * element, so the successful allocations (if any) must
2234 			 * be moved just before tbin->avail before bailing out.
2235 			 */
2236 			if (i > 0) {
2237 				memmove(tbin->avail - i, tbin->avail - nfill,
2238 				    i * sizeof(void *));
2239 			}
2240 			break;
2241 		}
2242 		if (config_fill && unlikely(opt_junk_alloc)) {
2243 			arena_alloc_junk_small(ptr, &arena_bin_info[binind],
2244 			    true);
2245 		}
2246 		/* Insert such that low regions get used first. */
2247 		*(tbin->avail - nfill + i) = ptr;
2248 	}
2249 	if (config_stats) {
2250 		bin->stats.nmalloc += i;
2251 		bin->stats.nrequests += tbin->tstats.nrequests;
2252 		bin->stats.curregs += i;
2253 		bin->stats.nfills++;
2254 		tbin->tstats.nrequests = 0;
2255 	}
2256 	malloc_mutex_unlock(&bin->lock);
2257 	tbin->ncached = i;
2258 	arena_decay_tick(tsd, arena);
2259 }
2260 
2261 void
2262 arena_alloc_junk_small(void *ptr, arena_bin_info_t *bin_info, bool zero)
2263 {
2264 
2265 	if (zero) {
2266 		size_t redzone_size = bin_info->redzone_size;
2267 		memset((void *)((uintptr_t)ptr - redzone_size), 0xa5,
2268 		    redzone_size);
2269 		memset((void *)((uintptr_t)ptr + bin_info->reg_size), 0xa5,
2270 		    redzone_size);
2271 	} else {
2272 		memset((void *)((uintptr_t)ptr - bin_info->redzone_size), 0xa5,
2273 		    bin_info->reg_interval);
2274 	}
2275 }
2276 
2277 #ifdef JEMALLOC_JET
2278 #undef arena_redzone_corruption
2279 #define	arena_redzone_corruption JEMALLOC_N(arena_redzone_corruption_impl)
2280 #endif
2281 static void
2282 arena_redzone_corruption(void *ptr, size_t usize, bool after,
2283     size_t offset, uint8_t byte)
2284 {
2285 
2286 	malloc_printf("<jemalloc>: Corrupt redzone %zu byte%s %s %p "
2287 	    "(size %zu), byte=%#x\n", offset, (offset == 1) ? "" : "s",
2288 	    after ? "after" : "before", ptr, usize, byte);
2289 }
2290 #ifdef JEMALLOC_JET
2291 #undef arena_redzone_corruption
2292 #define	arena_redzone_corruption JEMALLOC_N(arena_redzone_corruption)
2293 arena_redzone_corruption_t *arena_redzone_corruption =
2294     JEMALLOC_N(arena_redzone_corruption_impl);
2295 #endif
2296 
2297 static void
2298 arena_redzones_validate(void *ptr, arena_bin_info_t *bin_info, bool reset)
2299 {
2300 	bool error = false;
2301 
2302 	if (opt_junk_alloc) {
2303 		size_t size = bin_info->reg_size;
2304 		size_t redzone_size = bin_info->redzone_size;
2305 		size_t i;
2306 
2307 		for (i = 1; i <= redzone_size; i++) {
2308 			uint8_t *byte = (uint8_t *)((uintptr_t)ptr - i);
2309 			if (*byte != 0xa5) {
2310 				error = true;
2311 				arena_redzone_corruption(ptr, size, false, i,
2312 				    *byte);
2313 				if (reset)
2314 					*byte = 0xa5;
2315 			}
2316 		}
2317 		for (i = 0; i < redzone_size; i++) {
2318 			uint8_t *byte = (uint8_t *)((uintptr_t)ptr + size + i);
2319 			if (*byte != 0xa5) {
2320 				error = true;
2321 				arena_redzone_corruption(ptr, size, true, i,
2322 				    *byte);
2323 				if (reset)
2324 					*byte = 0xa5;
2325 			}
2326 		}
2327 	}
2328 
2329 	if (opt_abort && error)
2330 		abort();
2331 }
2332 
2333 #ifdef JEMALLOC_JET
2334 #undef arena_dalloc_junk_small
2335 #define	arena_dalloc_junk_small JEMALLOC_N(arena_dalloc_junk_small_impl)
2336 #endif
2337 void
2338 arena_dalloc_junk_small(void *ptr, arena_bin_info_t *bin_info)
2339 {
2340 	size_t redzone_size = bin_info->redzone_size;
2341 
2342 	arena_redzones_validate(ptr, bin_info, false);
2343 	memset((void *)((uintptr_t)ptr - redzone_size), 0x5a,
2344 	    bin_info->reg_interval);
2345 }
2346 #ifdef JEMALLOC_JET
2347 #undef arena_dalloc_junk_small
2348 #define	arena_dalloc_junk_small JEMALLOC_N(arena_dalloc_junk_small)
2349 arena_dalloc_junk_small_t *arena_dalloc_junk_small =
2350     JEMALLOC_N(arena_dalloc_junk_small_impl);
2351 #endif
2352 
2353 void
2354 arena_quarantine_junk_small(void *ptr, size_t usize)
2355 {
2356 	szind_t binind;
2357 	arena_bin_info_t *bin_info;
2358 	cassert(config_fill);
2359 	assert(opt_junk_free);
2360 	assert(opt_quarantine);
2361 	assert(usize <= SMALL_MAXCLASS);
2362 
2363 	binind = size2index(usize);
2364 	bin_info = &arena_bin_info[binind];
2365 	arena_redzones_validate(ptr, bin_info, true);
2366 }
2367 
2368 static void *
2369 arena_malloc_small(tsd_t *tsd, arena_t *arena, szind_t binind, bool zero)
2370 {
2371 	void *ret;
2372 	arena_bin_t *bin;
2373 	size_t usize;
2374 	arena_run_t *run;
2375 
2376 	assert(binind < NBINS);
2377 	bin = &arena->bins[binind];
2378 	usize = index2size(binind);
2379 
2380 	malloc_mutex_lock(&bin->lock);
2381 	if ((run = bin->runcur) != NULL && run->nfree > 0)
2382 		ret = arena_run_reg_alloc(run, &arena_bin_info[binind]);
2383 	else
2384 		ret = arena_bin_malloc_hard(arena, bin);
2385 
2386 	if (ret == NULL) {
2387 		malloc_mutex_unlock(&bin->lock);
2388 		return (NULL);
2389 	}
2390 
2391 	if (config_stats) {
2392 		bin->stats.nmalloc++;
2393 		bin->stats.nrequests++;
2394 		bin->stats.curregs++;
2395 	}
2396 	malloc_mutex_unlock(&bin->lock);
2397 	if (config_prof && !isthreaded && arena_prof_accum(arena, usize))
2398 		prof_idump();
2399 
2400 	if (!zero) {
2401 		if (config_fill) {
2402 			if (unlikely(opt_junk_alloc)) {
2403 				arena_alloc_junk_small(ret,
2404 				    &arena_bin_info[binind], false);
2405 			} else if (unlikely(opt_zero))
2406 				memset(ret, 0, usize);
2407 		}
2408 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, usize);
2409 	} else {
2410 		if (config_fill && unlikely(opt_junk_alloc)) {
2411 			arena_alloc_junk_small(ret, &arena_bin_info[binind],
2412 			    true);
2413 		}
2414 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, usize);
2415 		memset(ret, 0, usize);
2416 	}
2417 
2418 	arena_decay_tick(tsd, arena);
2419 	return (ret);
2420 }
2421 
2422 void *
2423 arena_malloc_large(tsd_t *tsd, arena_t *arena, szind_t binind, bool zero)
2424 {
2425 	void *ret;
2426 	size_t usize;
2427 	uintptr_t random_offset;
2428 	arena_run_t *run;
2429 	arena_chunk_map_misc_t *miscelm;
2430 	UNUSED bool idump;
2431 
2432 	/* Large allocation. */
2433 	usize = index2size(binind);
2434 	malloc_mutex_lock(&arena->lock);
2435 	if (config_cache_oblivious) {
2436 		uint64_t r;
2437 
2438 		/*
2439 		 * Compute a uniformly distributed offset within the first page
2440 		 * that is a multiple of the cacheline size, e.g. [0 .. 63) * 64
2441 		 * for 4 KiB pages and 64-byte cachelines.
2442 		 */
2443 		r = prng_lg_range(&arena->offset_state, LG_PAGE - LG_CACHELINE);
2444 		random_offset = ((uintptr_t)r) << LG_CACHELINE;
2445 	} else
2446 		random_offset = 0;
2447 	run = arena_run_alloc_large(arena, usize + large_pad, zero);
2448 	if (run == NULL) {
2449 		malloc_mutex_unlock(&arena->lock);
2450 		return (NULL);
2451 	}
2452 	miscelm = arena_run_to_miscelm(run);
2453 	ret = (void *)((uintptr_t)arena_miscelm_to_rpages(miscelm) +
2454 	    random_offset);
2455 	if (config_stats) {
2456 		szind_t index = binind - NBINS;
2457 
2458 		arena->stats.nmalloc_large++;
2459 		arena->stats.nrequests_large++;
2460 		arena->stats.allocated_large += usize;
2461 		arena->stats.lstats[index].nmalloc++;
2462 		arena->stats.lstats[index].nrequests++;
2463 		arena->stats.lstats[index].curruns++;
2464 	}
2465 	if (config_prof)
2466 		idump = arena_prof_accum_locked(arena, usize);
2467 	malloc_mutex_unlock(&arena->lock);
2468 	if (config_prof && idump)
2469 		prof_idump();
2470 
2471 	if (!zero) {
2472 		if (config_fill) {
2473 			if (unlikely(opt_junk_alloc))
2474 				memset(ret, 0xa5, usize);
2475 			else if (unlikely(opt_zero))
2476 				memset(ret, 0, usize);
2477 		}
2478 	}
2479 
2480 	arena_decay_tick(tsd, arena);
2481 	return (ret);
2482 }
2483 
2484 void *
2485 arena_malloc_hard(tsd_t *tsd, arena_t *arena, size_t size, szind_t ind,
2486     bool zero, tcache_t *tcache)
2487 {
2488 
2489 	arena = arena_choose(tsd, arena);
2490 	if (unlikely(arena == NULL))
2491 		return (NULL);
2492 
2493 	if (likely(size <= SMALL_MAXCLASS))
2494 		return (arena_malloc_small(tsd, arena, ind, zero));
2495 	if (likely(size <= large_maxclass))
2496 		return (arena_malloc_large(tsd, arena, ind, zero));
2497 	return (huge_malloc(tsd, arena, index2size(ind), zero, tcache));
2498 }
2499 
2500 /* Only handles large allocations that require more than page alignment. */
2501 static void *
2502 arena_palloc_large(tsd_t *tsd, arena_t *arena, size_t usize, size_t alignment,
2503     bool zero)
2504 {
2505 	void *ret;
2506 	size_t alloc_size, leadsize, trailsize;
2507 	arena_run_t *run;
2508 	arena_chunk_t *chunk;
2509 	arena_chunk_map_misc_t *miscelm;
2510 	void *rpages;
2511 
2512 	assert(usize == PAGE_CEILING(usize));
2513 
2514 	arena = arena_choose(tsd, arena);
2515 	if (unlikely(arena == NULL))
2516 		return (NULL);
2517 
2518 	alignment = PAGE_CEILING(alignment);
2519 	alloc_size = usize + large_pad + alignment - PAGE;
2520 
2521 	malloc_mutex_lock(&arena->lock);
2522 	run = arena_run_alloc_large(arena, alloc_size, false);
2523 	if (run == NULL) {
2524 		malloc_mutex_unlock(&arena->lock);
2525 		return (NULL);
2526 	}
2527 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run);
2528 	miscelm = arena_run_to_miscelm(run);
2529 	rpages = arena_miscelm_to_rpages(miscelm);
2530 
2531 	leadsize = ALIGNMENT_CEILING((uintptr_t)rpages, alignment) -
2532 	    (uintptr_t)rpages;
2533 	assert(alloc_size >= leadsize + usize);
2534 	trailsize = alloc_size - leadsize - usize - large_pad;
2535 	if (leadsize != 0) {
2536 		arena_chunk_map_misc_t *head_miscelm = miscelm;
2537 		arena_run_t *head_run = run;
2538 
2539 		miscelm = arena_miscelm_get(chunk,
2540 		    arena_miscelm_to_pageind(head_miscelm) + (leadsize >>
2541 		    LG_PAGE));
2542 		run = &miscelm->run;
2543 
2544 		arena_run_trim_head(arena, chunk, head_run, alloc_size,
2545 		    alloc_size - leadsize);
2546 	}
2547 	if (trailsize != 0) {
2548 		arena_run_trim_tail(arena, chunk, run, usize + large_pad +
2549 		    trailsize, usize + large_pad, false);
2550 	}
2551 	if (arena_run_init_large(arena, run, usize + large_pad, zero)) {
2552 		size_t run_ind =
2553 		    arena_miscelm_to_pageind(arena_run_to_miscelm(run));
2554 		bool dirty = (arena_mapbits_dirty_get(chunk, run_ind) != 0);
2555 		bool decommitted = (arena_mapbits_decommitted_get(chunk,
2556 		    run_ind) != 0);
2557 
2558 		assert(decommitted); /* Cause of OOM. */
2559 		arena_run_dalloc(arena, run, dirty, false, decommitted);
2560 		malloc_mutex_unlock(&arena->lock);
2561 		return (NULL);
2562 	}
2563 	ret = arena_miscelm_to_rpages(miscelm);
2564 
2565 	if (config_stats) {
2566 		szind_t index = size2index(usize) - NBINS;
2567 
2568 		arena->stats.nmalloc_large++;
2569 		arena->stats.nrequests_large++;
2570 		arena->stats.allocated_large += usize;
2571 		arena->stats.lstats[index].nmalloc++;
2572 		arena->stats.lstats[index].nrequests++;
2573 		arena->stats.lstats[index].curruns++;
2574 	}
2575 	malloc_mutex_unlock(&arena->lock);
2576 
2577 	if (config_fill && !zero) {
2578 		if (unlikely(opt_junk_alloc))
2579 			memset(ret, 0xa5, usize);
2580 		else if (unlikely(opt_zero))
2581 			memset(ret, 0, usize);
2582 	}
2583 	arena_decay_tick(tsd, arena);
2584 	return (ret);
2585 }
2586 
2587 void *
2588 arena_palloc(tsd_t *tsd, arena_t *arena, size_t usize, size_t alignment,
2589     bool zero, tcache_t *tcache)
2590 {
2591 	void *ret;
2592 
2593 	if (usize <= SMALL_MAXCLASS && (alignment < PAGE || (alignment == PAGE
2594 	    && (usize & PAGE_MASK) == 0))) {
2595 		/* Small; alignment doesn't require special run placement. */
2596 		ret = arena_malloc(tsd, arena, usize, size2index(usize), zero,
2597 		    tcache, true);
2598 	} else if (usize <= large_maxclass && alignment <= PAGE) {
2599 		/*
2600 		 * Large; alignment doesn't require special run placement.
2601 		 * However, the cached pointer may be at a random offset from
2602 		 * the base of the run, so do some bit manipulation to retrieve
2603 		 * the base.
2604 		 */
2605 		ret = arena_malloc(tsd, arena, usize, size2index(usize), zero,
2606 		    tcache, true);
2607 		if (config_cache_oblivious)
2608 			ret = (void *)((uintptr_t)ret & ~PAGE_MASK);
2609 	} else {
2610 		if (likely(usize <= large_maxclass)) {
2611 			ret = arena_palloc_large(tsd, arena, usize, alignment,
2612 			    zero);
2613 		} else if (likely(alignment <= chunksize))
2614 			ret = huge_malloc(tsd, arena, usize, zero, tcache);
2615 		else {
2616 			ret = huge_palloc(tsd, arena, usize, alignment, zero,
2617 			    tcache);
2618 		}
2619 	}
2620 	return (ret);
2621 }
2622 
2623 void
2624 arena_prof_promoted(const void *ptr, size_t size)
2625 {
2626 	arena_chunk_t *chunk;
2627 	size_t pageind;
2628 	szind_t binind;
2629 
2630 	cassert(config_prof);
2631 	assert(ptr != NULL);
2632 	assert(CHUNK_ADDR2BASE(ptr) != ptr);
2633 	assert(isalloc(ptr, false) == LARGE_MINCLASS);
2634 	assert(isalloc(ptr, true) == LARGE_MINCLASS);
2635 	assert(size <= SMALL_MAXCLASS);
2636 
2637 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr);
2638 	pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2639 	binind = size2index(size);
2640 	assert(binind < NBINS);
2641 	arena_mapbits_large_binind_set(chunk, pageind, binind);
2642 
2643 	assert(isalloc(ptr, false) == LARGE_MINCLASS);
2644 	assert(isalloc(ptr, true) == size);
2645 }
2646 
2647 static void
2648 arena_dissociate_bin_run(arena_chunk_t *chunk, arena_run_t *run,
2649     arena_bin_t *bin)
2650 {
2651 
2652 	/* Dissociate run from bin. */
2653 	if (run == bin->runcur)
2654 		bin->runcur = NULL;
2655 	else {
2656 		szind_t binind = arena_bin_index(extent_node_arena_get(
2657 		    &chunk->node), bin);
2658 		arena_bin_info_t *bin_info = &arena_bin_info[binind];
2659 
2660 		if (bin_info->nregs != 1) {
2661 			/*
2662 			 * This block's conditional is necessary because if the
2663 			 * run only contains one region, then it never gets
2664 			 * inserted into the non-full runs tree.
2665 			 */
2666 			arena_bin_runs_remove(bin, run);
2667 		}
2668 	}
2669 }
2670 
2671 static void
2672 arena_dalloc_bin_run(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
2673     arena_bin_t *bin)
2674 {
2675 
2676 	assert(run != bin->runcur);
2677 	assert(arena_run_tree_search(&bin->runs, arena_run_to_miscelm(run)) ==
2678 	    NULL);
2679 
2680 	malloc_mutex_unlock(&bin->lock);
2681 	/******************************/
2682 	malloc_mutex_lock(&arena->lock);
2683 	arena_run_dalloc(arena, run, true, false, false);
2684 	malloc_mutex_unlock(&arena->lock);
2685 	/****************************/
2686 	malloc_mutex_lock(&bin->lock);
2687 	if (config_stats)
2688 		bin->stats.curruns--;
2689 }
2690 
2691 static void
2692 arena_bin_lower_run(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run,
2693     arena_bin_t *bin)
2694 {
2695 
2696 	/*
2697 	 * Make sure that if bin->runcur is non-NULL, it refers to the lowest
2698 	 * non-full run.  It is okay to NULL runcur out rather than proactively
2699 	 * keeping it pointing at the lowest non-full run.
2700 	 */
2701 	if ((uintptr_t)run < (uintptr_t)bin->runcur) {
2702 		/* Switch runcur. */
2703 		if (bin->runcur->nfree > 0)
2704 			arena_bin_runs_insert(bin, bin->runcur);
2705 		bin->runcur = run;
2706 		if (config_stats)
2707 			bin->stats.reruns++;
2708 	} else
2709 		arena_bin_runs_insert(bin, run);
2710 }
2711 
2712 static void
2713 arena_dalloc_bin_locked_impl(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2714     arena_chunk_map_bits_t *bitselm, bool junked)
2715 {
2716 	size_t pageind, rpages_ind;
2717 	arena_run_t *run;
2718 	arena_bin_t *bin;
2719 	arena_bin_info_t *bin_info;
2720 	szind_t binind;
2721 
2722 	pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2723 	rpages_ind = pageind - arena_mapbits_small_runind_get(chunk, pageind);
2724 	run = &arena_miscelm_get(chunk, rpages_ind)->run;
2725 	binind = run->binind;
2726 	bin = &arena->bins[binind];
2727 	bin_info = &arena_bin_info[binind];
2728 
2729 	if (!junked && config_fill && unlikely(opt_junk_free))
2730 		arena_dalloc_junk_small(ptr, bin_info);
2731 
2732 	arena_run_reg_dalloc(run, ptr);
2733 	if (run->nfree == bin_info->nregs) {
2734 		arena_dissociate_bin_run(chunk, run, bin);
2735 		arena_dalloc_bin_run(arena, chunk, run, bin);
2736 	} else if (run->nfree == 1 && run != bin->runcur)
2737 		arena_bin_lower_run(arena, chunk, run, bin);
2738 
2739 	if (config_stats) {
2740 		bin->stats.ndalloc++;
2741 		bin->stats.curregs--;
2742 	}
2743 }
2744 
2745 void
2746 arena_dalloc_bin_junked_locked(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2747     arena_chunk_map_bits_t *bitselm)
2748 {
2749 
2750 	arena_dalloc_bin_locked_impl(arena, chunk, ptr, bitselm, true);
2751 }
2752 
2753 void
2754 arena_dalloc_bin(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2755     size_t pageind, arena_chunk_map_bits_t *bitselm)
2756 {
2757 	arena_run_t *run;
2758 	arena_bin_t *bin;
2759 	size_t rpages_ind;
2760 
2761 	rpages_ind = pageind - arena_mapbits_small_runind_get(chunk, pageind);
2762 	run = &arena_miscelm_get(chunk, rpages_ind)->run;
2763 	bin = &arena->bins[run->binind];
2764 	malloc_mutex_lock(&bin->lock);
2765 	arena_dalloc_bin_locked_impl(arena, chunk, ptr, bitselm, false);
2766 	malloc_mutex_unlock(&bin->lock);
2767 }
2768 
2769 void
2770 arena_dalloc_small(tsd_t *tsd, arena_t *arena, arena_chunk_t *chunk, void *ptr,
2771     size_t pageind)
2772 {
2773 	arena_chunk_map_bits_t *bitselm;
2774 
2775 	if (config_debug) {
2776 		/* arena_ptr_small_binind_get() does extra sanity checking. */
2777 		assert(arena_ptr_small_binind_get(ptr, arena_mapbits_get(chunk,
2778 		    pageind)) != BININD_INVALID);
2779 	}
2780 	bitselm = arena_bitselm_get(chunk, pageind);
2781 	arena_dalloc_bin(arena, chunk, ptr, pageind, bitselm);
2782 	arena_decay_tick(tsd, arena);
2783 }
2784 
2785 #ifdef JEMALLOC_JET
2786 #undef arena_dalloc_junk_large
2787 #define	arena_dalloc_junk_large JEMALLOC_N(arena_dalloc_junk_large_impl)
2788 #endif
2789 void
2790 arena_dalloc_junk_large(void *ptr, size_t usize)
2791 {
2792 
2793 	if (config_fill && unlikely(opt_junk_free))
2794 		memset(ptr, 0x5a, usize);
2795 }
2796 #ifdef JEMALLOC_JET
2797 #undef arena_dalloc_junk_large
2798 #define	arena_dalloc_junk_large JEMALLOC_N(arena_dalloc_junk_large)
2799 arena_dalloc_junk_large_t *arena_dalloc_junk_large =
2800     JEMALLOC_N(arena_dalloc_junk_large_impl);
2801 #endif
2802 
2803 static void
2804 arena_dalloc_large_locked_impl(arena_t *arena, arena_chunk_t *chunk,
2805     void *ptr, bool junked)
2806 {
2807 	size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2808 	arena_chunk_map_misc_t *miscelm = arena_miscelm_get(chunk, pageind);
2809 	arena_run_t *run = &miscelm->run;
2810 
2811 	if (config_fill || config_stats) {
2812 		size_t usize = arena_mapbits_large_size_get(chunk, pageind) -
2813 		    large_pad;
2814 
2815 		if (!junked)
2816 			arena_dalloc_junk_large(ptr, usize);
2817 		if (config_stats) {
2818 			szind_t index = size2index(usize) - NBINS;
2819 
2820 			arena->stats.ndalloc_large++;
2821 			arena->stats.allocated_large -= usize;
2822 			arena->stats.lstats[index].ndalloc++;
2823 			arena->stats.lstats[index].curruns--;
2824 		}
2825 	}
2826 
2827 	arena_run_dalloc(arena, run, true, false, false);
2828 }
2829 
2830 void
2831 arena_dalloc_large_junked_locked(arena_t *arena, arena_chunk_t *chunk,
2832     void *ptr)
2833 {
2834 
2835 	arena_dalloc_large_locked_impl(arena, chunk, ptr, true);
2836 }
2837 
2838 void
2839 arena_dalloc_large(tsd_t *tsd, arena_t *arena, arena_chunk_t *chunk, void *ptr)
2840 {
2841 
2842 	malloc_mutex_lock(&arena->lock);
2843 	arena_dalloc_large_locked_impl(arena, chunk, ptr, false);
2844 	malloc_mutex_unlock(&arena->lock);
2845 	arena_decay_tick(tsd, arena);
2846 }
2847 
2848 static void
2849 arena_ralloc_large_shrink(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2850     size_t oldsize, size_t size)
2851 {
2852 	size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2853 	arena_chunk_map_misc_t *miscelm = arena_miscelm_get(chunk, pageind);
2854 	arena_run_t *run = &miscelm->run;
2855 
2856 	assert(size < oldsize);
2857 
2858 	/*
2859 	 * Shrink the run, and make trailing pages available for other
2860 	 * allocations.
2861 	 */
2862 	malloc_mutex_lock(&arena->lock);
2863 	arena_run_trim_tail(arena, chunk, run, oldsize + large_pad, size +
2864 	    large_pad, true);
2865 	if (config_stats) {
2866 		szind_t oldindex = size2index(oldsize) - NBINS;
2867 		szind_t index = size2index(size) - NBINS;
2868 
2869 		arena->stats.ndalloc_large++;
2870 		arena->stats.allocated_large -= oldsize;
2871 		arena->stats.lstats[oldindex].ndalloc++;
2872 		arena->stats.lstats[oldindex].curruns--;
2873 
2874 		arena->stats.nmalloc_large++;
2875 		arena->stats.nrequests_large++;
2876 		arena->stats.allocated_large += size;
2877 		arena->stats.lstats[index].nmalloc++;
2878 		arena->stats.lstats[index].nrequests++;
2879 		arena->stats.lstats[index].curruns++;
2880 	}
2881 	malloc_mutex_unlock(&arena->lock);
2882 }
2883 
2884 static bool
2885 arena_ralloc_large_grow(arena_t *arena, arena_chunk_t *chunk, void *ptr,
2886     size_t oldsize, size_t usize_min, size_t usize_max, bool zero)
2887 {
2888 	size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE;
2889 	size_t npages = (oldsize + large_pad) >> LG_PAGE;
2890 	size_t followsize;
2891 
2892 	assert(oldsize == arena_mapbits_large_size_get(chunk, pageind) -
2893 	    large_pad);
2894 
2895 	/* Try to extend the run. */
2896 	malloc_mutex_lock(&arena->lock);
2897 	if (pageind+npages >= chunk_npages || arena_mapbits_allocated_get(chunk,
2898 	    pageind+npages) != 0)
2899 		goto label_fail;
2900 	followsize = arena_mapbits_unallocated_size_get(chunk, pageind+npages);
2901 	if (oldsize + followsize >= usize_min) {
2902 		/*
2903 		 * The next run is available and sufficiently large.  Split the
2904 		 * following run, then merge the first part with the existing
2905 		 * allocation.
2906 		 */
2907 		arena_run_t *run;
2908 		size_t usize, splitsize, size, flag_dirty, flag_unzeroed_mask;
2909 
2910 		usize = usize_max;
2911 		while (oldsize + followsize < usize)
2912 			usize = index2size(size2index(usize)-1);
2913 		assert(usize >= usize_min);
2914 		assert(usize >= oldsize);
2915 		splitsize = usize - oldsize;
2916 		if (splitsize == 0)
2917 			goto label_fail;
2918 
2919 		run = &arena_miscelm_get(chunk, pageind+npages)->run;
2920 		if (arena_run_split_large(arena, run, splitsize, zero))
2921 			goto label_fail;
2922 
2923 		if (config_cache_oblivious && zero) {
2924 			/*
2925 			 * Zero the trailing bytes of the original allocation's
2926 			 * last page, since they are in an indeterminate state.
2927 			 * There will always be trailing bytes, because ptr's
2928 			 * offset from the beginning of the run is a multiple of
2929 			 * CACHELINE in [0 .. PAGE).
2930 			 */
2931 			void *zbase = (void *)((uintptr_t)ptr + oldsize);
2932 			void *zpast = PAGE_ADDR2BASE((void *)((uintptr_t)zbase +
2933 			    PAGE));
2934 			size_t nzero = (uintptr_t)zpast - (uintptr_t)zbase;
2935 			assert(nzero > 0);
2936 			memset(zbase, 0, nzero);
2937 		}
2938 
2939 		size = oldsize + splitsize;
2940 		npages = (size + large_pad) >> LG_PAGE;
2941 
2942 		/*
2943 		 * Mark the extended run as dirty if either portion of the run
2944 		 * was dirty before allocation.  This is rather pedantic,
2945 		 * because there's not actually any sequence of events that
2946 		 * could cause the resulting run to be passed to
2947 		 * arena_run_dalloc() with the dirty argument set to false
2948 		 * (which is when dirty flag consistency would really matter).
2949 		 */
2950 		flag_dirty = arena_mapbits_dirty_get(chunk, pageind) |
2951 		    arena_mapbits_dirty_get(chunk, pageind+npages-1);
2952 		flag_unzeroed_mask = flag_dirty == 0 ? CHUNK_MAP_UNZEROED : 0;
2953 		arena_mapbits_large_set(chunk, pageind, size + large_pad,
2954 		    flag_dirty | (flag_unzeroed_mask &
2955 		    arena_mapbits_unzeroed_get(chunk, pageind)));
2956 		arena_mapbits_large_set(chunk, pageind+npages-1, 0, flag_dirty |
2957 		    (flag_unzeroed_mask & arena_mapbits_unzeroed_get(chunk,
2958 		    pageind+npages-1)));
2959 
2960 		if (config_stats) {
2961 			szind_t oldindex = size2index(oldsize) - NBINS;
2962 			szind_t index = size2index(size) - NBINS;
2963 
2964 			arena->stats.ndalloc_large++;
2965 			arena->stats.allocated_large -= oldsize;
2966 			arena->stats.lstats[oldindex].ndalloc++;
2967 			arena->stats.lstats[oldindex].curruns--;
2968 
2969 			arena->stats.nmalloc_large++;
2970 			arena->stats.nrequests_large++;
2971 			arena->stats.allocated_large += size;
2972 			arena->stats.lstats[index].nmalloc++;
2973 			arena->stats.lstats[index].nrequests++;
2974 			arena->stats.lstats[index].curruns++;
2975 		}
2976 		malloc_mutex_unlock(&arena->lock);
2977 		return (false);
2978 	}
2979 label_fail:
2980 	malloc_mutex_unlock(&arena->lock);
2981 	return (true);
2982 }
2983 
2984 #ifdef JEMALLOC_JET
2985 #undef arena_ralloc_junk_large
2986 #define	arena_ralloc_junk_large JEMALLOC_N(arena_ralloc_junk_large_impl)
2987 #endif
2988 static void
2989 arena_ralloc_junk_large(void *ptr, size_t old_usize, size_t usize)
2990 {
2991 
2992 	if (config_fill && unlikely(opt_junk_free)) {
2993 		memset((void *)((uintptr_t)ptr + usize), 0x5a,
2994 		    old_usize - usize);
2995 	}
2996 }
2997 #ifdef JEMALLOC_JET
2998 #undef arena_ralloc_junk_large
2999 #define	arena_ralloc_junk_large JEMALLOC_N(arena_ralloc_junk_large)
3000 arena_ralloc_junk_large_t *arena_ralloc_junk_large =
3001     JEMALLOC_N(arena_ralloc_junk_large_impl);
3002 #endif
3003 
3004 /*
3005  * Try to resize a large allocation, in order to avoid copying.  This will
3006  * always fail if growing an object, and the following run is already in use.
3007  */
3008 static bool
3009 arena_ralloc_large(void *ptr, size_t oldsize, size_t usize_min,
3010     size_t usize_max, bool zero)
3011 {
3012 	arena_chunk_t *chunk;
3013 	arena_t *arena;
3014 
3015 	if (oldsize == usize_max) {
3016 		/* Current size class is compatible and maximal. */
3017 		return (false);
3018 	}
3019 
3020 	chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr);
3021 	arena = extent_node_arena_get(&chunk->node);
3022 
3023 	if (oldsize < usize_max) {
3024 		bool ret = arena_ralloc_large_grow(arena, chunk, ptr, oldsize,
3025 		    usize_min, usize_max, zero);
3026 		if (config_fill && !ret && !zero) {
3027 			if (unlikely(opt_junk_alloc)) {
3028 				memset((void *)((uintptr_t)ptr + oldsize), 0xa5,
3029 				    isalloc(ptr, config_prof) - oldsize);
3030 			} else if (unlikely(opt_zero)) {
3031 				memset((void *)((uintptr_t)ptr + oldsize), 0,
3032 				    isalloc(ptr, config_prof) - oldsize);
3033 			}
3034 		}
3035 		return (ret);
3036 	}
3037 
3038 	assert(oldsize > usize_max);
3039 	/* Fill before shrinking in order avoid a race. */
3040 	arena_ralloc_junk_large(ptr, oldsize, usize_max);
3041 	arena_ralloc_large_shrink(arena, chunk, ptr, oldsize, usize_max);
3042 	return (false);
3043 }
3044 
3045 bool
3046 arena_ralloc_no_move(tsd_t *tsd, void *ptr, size_t oldsize, size_t size,
3047     size_t extra, bool zero)
3048 {
3049 	size_t usize_min, usize_max;
3050 
3051 	/* Calls with non-zero extra had to clamp extra. */
3052 	assert(extra == 0 || size + extra <= HUGE_MAXCLASS);
3053 
3054 	if (unlikely(size > HUGE_MAXCLASS))
3055 		return (true);
3056 
3057 	usize_min = s2u(size);
3058 	usize_max = s2u(size + extra);
3059 	if (likely(oldsize <= large_maxclass && usize_min <= large_maxclass)) {
3060 		arena_chunk_t *chunk;
3061 
3062 		/*
3063 		 * Avoid moving the allocation if the size class can be left the
3064 		 * same.
3065 		 */
3066 		if (oldsize <= SMALL_MAXCLASS) {
3067 			assert(arena_bin_info[size2index(oldsize)].reg_size ==
3068 			    oldsize);
3069 			if ((usize_max > SMALL_MAXCLASS ||
3070 			    size2index(usize_max) != size2index(oldsize)) &&
3071 			    (size > oldsize || usize_max < oldsize))
3072 				return (true);
3073 		} else {
3074 			if (usize_max <= SMALL_MAXCLASS)
3075 				return (true);
3076 			if (arena_ralloc_large(ptr, oldsize, usize_min,
3077 			    usize_max, zero))
3078 				return (true);
3079 		}
3080 
3081 		chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr);
3082 		arena_decay_tick(tsd, extent_node_arena_get(&chunk->node));
3083 		return (false);
3084 	} else {
3085 		return (huge_ralloc_no_move(tsd, ptr, oldsize, usize_min,
3086 		    usize_max, zero));
3087 	}
3088 }
3089 
3090 static void *
3091 arena_ralloc_move_helper(tsd_t *tsd, arena_t *arena, size_t usize,
3092     size_t alignment, bool zero, tcache_t *tcache)
3093 {
3094 
3095 	if (alignment == 0)
3096 		return (arena_malloc(tsd, arena, usize, size2index(usize), zero,
3097 		    tcache, true));
3098 	usize = sa2u(usize, alignment);
3099 	if (unlikely(usize == 0 || usize > HUGE_MAXCLASS))
3100 		return (NULL);
3101 	return (ipalloct(tsd, usize, alignment, zero, tcache, arena));
3102 }
3103 
3104 void *
3105 arena_ralloc(tsd_t *tsd, arena_t *arena, void *ptr, size_t oldsize, size_t size,
3106     size_t alignment, bool zero, tcache_t *tcache)
3107 {
3108 	void *ret;
3109 	size_t usize;
3110 
3111 	usize = s2u(size);
3112 	if (unlikely(usize == 0 || size > HUGE_MAXCLASS))
3113 		return (NULL);
3114 
3115 	if (likely(usize <= large_maxclass)) {
3116 		size_t copysize;
3117 
3118 		/* Try to avoid moving the allocation. */
3119 		if (!arena_ralloc_no_move(tsd, ptr, oldsize, usize, 0, zero))
3120 			return (ptr);
3121 
3122 		/*
3123 		 * size and oldsize are different enough that we need to move
3124 		 * the object.  In that case, fall back to allocating new space
3125 		 * and copying.
3126 		 */
3127 		ret = arena_ralloc_move_helper(tsd, arena, usize, alignment,
3128 		    zero, tcache);
3129 		if (ret == NULL)
3130 			return (NULL);
3131 
3132 		/*
3133 		 * Junk/zero-filling were already done by
3134 		 * ipalloc()/arena_malloc().
3135 		 */
3136 
3137 		copysize = (usize < oldsize) ? usize : oldsize;
3138 		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, copysize);
3139 		memcpy(ret, ptr, copysize);
3140 		isqalloc(tsd, ptr, oldsize, tcache);
3141 	} else {
3142 		ret = huge_ralloc(tsd, arena, ptr, oldsize, usize, alignment,
3143 		    zero, tcache);
3144 	}
3145 	return (ret);
3146 }
3147 
3148 dss_prec_t
3149 arena_dss_prec_get(arena_t *arena)
3150 {
3151 	dss_prec_t ret;
3152 
3153 	malloc_mutex_lock(&arena->lock);
3154 	ret = arena->dss_prec;
3155 	malloc_mutex_unlock(&arena->lock);
3156 	return (ret);
3157 }
3158 
3159 bool
3160 arena_dss_prec_set(arena_t *arena, dss_prec_t dss_prec)
3161 {
3162 
3163 	if (!have_dss)
3164 		return (dss_prec != dss_prec_disabled);
3165 	malloc_mutex_lock(&arena->lock);
3166 	arena->dss_prec = dss_prec;
3167 	malloc_mutex_unlock(&arena->lock);
3168 	return (false);
3169 }
3170 
3171 ssize_t
3172 arena_lg_dirty_mult_default_get(void)
3173 {
3174 
3175 	return ((ssize_t)atomic_read_z((size_t *)&lg_dirty_mult_default));
3176 }
3177 
3178 bool
3179 arena_lg_dirty_mult_default_set(ssize_t lg_dirty_mult)
3180 {
3181 
3182 	if (opt_purge != purge_mode_ratio)
3183 		return (true);
3184 	if (!arena_lg_dirty_mult_valid(lg_dirty_mult))
3185 		return (true);
3186 	atomic_write_z((size_t *)&lg_dirty_mult_default, (size_t)lg_dirty_mult);
3187 	return (false);
3188 }
3189 
3190 ssize_t
3191 arena_decay_time_default_get(void)
3192 {
3193 
3194 	return ((ssize_t)atomic_read_z((size_t *)&decay_time_default));
3195 }
3196 
3197 bool
3198 arena_decay_time_default_set(ssize_t decay_time)
3199 {
3200 
3201 	if (opt_purge != purge_mode_decay)
3202 		return (true);
3203 	if (!arena_decay_time_valid(decay_time))
3204 		return (true);
3205 	atomic_write_z((size_t *)&decay_time_default, (size_t)decay_time);
3206 	return (false);
3207 }
3208 
3209 static void
3210 arena_basic_stats_merge_locked(arena_t *arena, unsigned *nthreads,
3211     const char **dss, ssize_t *lg_dirty_mult, ssize_t *decay_time,
3212     size_t *nactive, size_t *ndirty)
3213 {
3214 
3215 	*nthreads += arena_nthreads_get(arena);
3216 	*dss = dss_prec_names[arena->dss_prec];
3217 	*lg_dirty_mult = arena->lg_dirty_mult;
3218 	*decay_time = arena->decay_time;
3219 	*nactive += arena->nactive;
3220 	*ndirty += arena->ndirty;
3221 }
3222 
3223 void
3224 arena_basic_stats_merge(arena_t *arena, unsigned *nthreads, const char **dss,
3225     ssize_t *lg_dirty_mult, ssize_t *decay_time, size_t *nactive,
3226     size_t *ndirty)
3227 {
3228 
3229 	malloc_mutex_lock(&arena->lock);
3230 	arena_basic_stats_merge_locked(arena, nthreads, dss, lg_dirty_mult,
3231 	    decay_time, nactive, ndirty);
3232 	malloc_mutex_unlock(&arena->lock);
3233 }
3234 
3235 void
3236 arena_stats_merge(arena_t *arena, unsigned *nthreads, const char **dss,
3237     ssize_t *lg_dirty_mult, ssize_t *decay_time, size_t *nactive,
3238     size_t *ndirty, arena_stats_t *astats, malloc_bin_stats_t *bstats,
3239     malloc_large_stats_t *lstats, malloc_huge_stats_t *hstats)
3240 {
3241 	unsigned i;
3242 
3243 	cassert(config_stats);
3244 
3245 	malloc_mutex_lock(&arena->lock);
3246 	arena_basic_stats_merge_locked(arena, nthreads, dss, lg_dirty_mult,
3247 	    decay_time, nactive, ndirty);
3248 
3249 	astats->mapped += arena->stats.mapped;
3250 	astats->npurge += arena->stats.npurge;
3251 	astats->nmadvise += arena->stats.nmadvise;
3252 	astats->purged += arena->stats.purged;
3253 	astats->metadata_mapped += arena->stats.metadata_mapped;
3254 	astats->metadata_allocated += arena_metadata_allocated_get(arena);
3255 	astats->allocated_large += arena->stats.allocated_large;
3256 	astats->nmalloc_large += arena->stats.nmalloc_large;
3257 	astats->ndalloc_large += arena->stats.ndalloc_large;
3258 	astats->nrequests_large += arena->stats.nrequests_large;
3259 	astats->allocated_huge += arena->stats.allocated_huge;
3260 	astats->nmalloc_huge += arena->stats.nmalloc_huge;
3261 	astats->ndalloc_huge += arena->stats.ndalloc_huge;
3262 
3263 	for (i = 0; i < nlclasses; i++) {
3264 		lstats[i].nmalloc += arena->stats.lstats[i].nmalloc;
3265 		lstats[i].ndalloc += arena->stats.lstats[i].ndalloc;
3266 		lstats[i].nrequests += arena->stats.lstats[i].nrequests;
3267 		lstats[i].curruns += arena->stats.lstats[i].curruns;
3268 	}
3269 
3270 	for (i = 0; i < nhclasses; i++) {
3271 		hstats[i].nmalloc += arena->stats.hstats[i].nmalloc;
3272 		hstats[i].ndalloc += arena->stats.hstats[i].ndalloc;
3273 		hstats[i].curhchunks += arena->stats.hstats[i].curhchunks;
3274 	}
3275 	malloc_mutex_unlock(&arena->lock);
3276 
3277 	for (i = 0; i < NBINS; i++) {
3278 		arena_bin_t *bin = &arena->bins[i];
3279 
3280 		malloc_mutex_lock(&bin->lock);
3281 		bstats[i].nmalloc += bin->stats.nmalloc;
3282 		bstats[i].ndalloc += bin->stats.ndalloc;
3283 		bstats[i].nrequests += bin->stats.nrequests;
3284 		bstats[i].curregs += bin->stats.curregs;
3285 		if (config_tcache) {
3286 			bstats[i].nfills += bin->stats.nfills;
3287 			bstats[i].nflushes += bin->stats.nflushes;
3288 		}
3289 		bstats[i].nruns += bin->stats.nruns;
3290 		bstats[i].reruns += bin->stats.reruns;
3291 		bstats[i].curruns += bin->stats.curruns;
3292 		malloc_mutex_unlock(&bin->lock);
3293 	}
3294 }
3295 
3296 unsigned
3297 arena_nthreads_get(arena_t *arena)
3298 {
3299 
3300 	return (atomic_read_u(&arena->nthreads));
3301 }
3302 
3303 void
3304 arena_nthreads_inc(arena_t *arena)
3305 {
3306 
3307 	atomic_add_u(&arena->nthreads, 1);
3308 }
3309 
3310 void
3311 arena_nthreads_dec(arena_t *arena)
3312 {
3313 
3314 	atomic_sub_u(&arena->nthreads, 1);
3315 }
3316 
3317 arena_t *
3318 arena_new(unsigned ind)
3319 {
3320 	arena_t *arena;
3321 	size_t arena_size;
3322 	unsigned i;
3323 	arena_bin_t *bin;
3324 
3325 	/* Compute arena size to incorporate sufficient runs_avail elements. */
3326 	arena_size = offsetof(arena_t, runs_avail) + (sizeof(arena_run_tree_t) *
3327 	    runs_avail_nclasses);
3328 	/*
3329 	 * Allocate arena, arena->lstats, and arena->hstats contiguously, mainly
3330 	 * because there is no way to clean up if base_alloc() OOMs.
3331 	 */
3332 	if (config_stats) {
3333 		arena = (arena_t *)base_alloc(CACHELINE_CEILING(arena_size) +
3334 		    QUANTUM_CEILING(nlclasses * sizeof(malloc_large_stats_t) +
3335 		    nhclasses) * sizeof(malloc_huge_stats_t));
3336 	} else
3337 		arena = (arena_t *)base_alloc(arena_size);
3338 	if (arena == NULL)
3339 		return (NULL);
3340 
3341 	arena->ind = ind;
3342 	arena->nthreads = 0;
3343 	if (malloc_mutex_init(&arena->lock))
3344 		return (NULL);
3345 
3346 	if (config_stats) {
3347 		memset(&arena->stats, 0, sizeof(arena_stats_t));
3348 		arena->stats.lstats = (malloc_large_stats_t *)((uintptr_t)arena
3349 		    + CACHELINE_CEILING(arena_size));
3350 		memset(arena->stats.lstats, 0, nlclasses *
3351 		    sizeof(malloc_large_stats_t));
3352 		arena->stats.hstats = (malloc_huge_stats_t *)((uintptr_t)arena
3353 		    + CACHELINE_CEILING(arena_size) +
3354 		    QUANTUM_CEILING(nlclasses * sizeof(malloc_large_stats_t)));
3355 		memset(arena->stats.hstats, 0, nhclasses *
3356 		    sizeof(malloc_huge_stats_t));
3357 		if (config_tcache)
3358 			ql_new(&arena->tcache_ql);
3359 	}
3360 
3361 	if (config_prof)
3362 		arena->prof_accumbytes = 0;
3363 
3364 	if (config_cache_oblivious) {
3365 		/*
3366 		 * A nondeterministic seed based on the address of arena reduces
3367 		 * the likelihood of lockstep non-uniform cache index
3368 		 * utilization among identical concurrent processes, but at the
3369 		 * cost of test repeatability.  For debug builds, instead use a
3370 		 * deterministic seed.
3371 		 */
3372 		arena->offset_state = config_debug ? ind :
3373 		    (uint64_t)(uintptr_t)arena;
3374 	}
3375 
3376 	arena->dss_prec = chunk_dss_prec_get();
3377 
3378 	arena->spare = NULL;
3379 
3380 	arena->lg_dirty_mult = arena_lg_dirty_mult_default_get();
3381 	arena->purging = false;
3382 	arena->nactive = 0;
3383 	arena->ndirty = 0;
3384 
3385 	for(i = 0; i < runs_avail_nclasses; i++)
3386 		arena_run_tree_new(&arena->runs_avail[i]);
3387 	qr_new(&arena->runs_dirty, rd_link);
3388 	qr_new(&arena->chunks_cache, cc_link);
3389 
3390 	if (opt_purge == purge_mode_decay)
3391 		arena_decay_init(arena, arena_decay_time_default_get());
3392 
3393 	ql_new(&arena->huge);
3394 	if (malloc_mutex_init(&arena->huge_mtx))
3395 		return (NULL);
3396 
3397 	extent_tree_szad_new(&arena->chunks_szad_cached);
3398 	extent_tree_ad_new(&arena->chunks_ad_cached);
3399 	extent_tree_szad_new(&arena->chunks_szad_retained);
3400 	extent_tree_ad_new(&arena->chunks_ad_retained);
3401 	if (malloc_mutex_init(&arena->chunks_mtx))
3402 		return (NULL);
3403 	ql_new(&arena->node_cache);
3404 	if (malloc_mutex_init(&arena->node_cache_mtx))
3405 		return (NULL);
3406 
3407 	arena->chunk_hooks = chunk_hooks_default;
3408 
3409 	/* Initialize bins. */
3410 	for (i = 0; i < NBINS; i++) {
3411 		bin = &arena->bins[i];
3412 		if (malloc_mutex_init(&bin->lock))
3413 			return (NULL);
3414 		bin->runcur = NULL;
3415 		arena_run_tree_new(&bin->runs);
3416 		if (config_stats)
3417 			memset(&bin->stats, 0, sizeof(malloc_bin_stats_t));
3418 	}
3419 
3420 	return (arena);
3421 }
3422 
3423 /*
3424  * Calculate bin_info->run_size such that it meets the following constraints:
3425  *
3426  *   *) bin_info->run_size <= arena_maxrun
3427  *   *) bin_info->nregs <= RUN_MAXREGS
3428  *
3429  * bin_info->nregs and bin_info->reg0_offset are also calculated here, since
3430  * these settings are all interdependent.
3431  */
3432 static void
3433 bin_info_run_size_calc(arena_bin_info_t *bin_info)
3434 {
3435 	size_t pad_size;
3436 	size_t try_run_size, perfect_run_size, actual_run_size;
3437 	uint32_t try_nregs, perfect_nregs, actual_nregs;
3438 
3439 	/*
3440 	 * Determine redzone size based on minimum alignment and minimum
3441 	 * redzone size.  Add padding to the end of the run if it is needed to
3442 	 * align the regions.  The padding allows each redzone to be half the
3443 	 * minimum alignment; without the padding, each redzone would have to
3444 	 * be twice as large in order to maintain alignment.
3445 	 */
3446 	if (config_fill && unlikely(opt_redzone)) {
3447 		size_t align_min = ZU(1) << (ffs_zu(bin_info->reg_size) - 1);
3448 		if (align_min <= REDZONE_MINSIZE) {
3449 			bin_info->redzone_size = REDZONE_MINSIZE;
3450 			pad_size = 0;
3451 		} else {
3452 			bin_info->redzone_size = align_min >> 1;
3453 			pad_size = bin_info->redzone_size;
3454 		}
3455 	} else {
3456 		bin_info->redzone_size = 0;
3457 		pad_size = 0;
3458 	}
3459 	bin_info->reg_interval = bin_info->reg_size +
3460 	    (bin_info->redzone_size << 1);
3461 
3462 	/*
3463 	 * Compute run size under ideal conditions (no redzones, no limit on run
3464 	 * size).
3465 	 */
3466 	try_run_size = PAGE;
3467 	try_nregs = (uint32_t)(try_run_size / bin_info->reg_size);
3468 	do {
3469 		perfect_run_size = try_run_size;
3470 		perfect_nregs = try_nregs;
3471 
3472 		try_run_size += PAGE;
3473 		try_nregs = (uint32_t)(try_run_size / bin_info->reg_size);
3474 	} while (perfect_run_size != perfect_nregs * bin_info->reg_size);
3475 	assert(perfect_nregs <= RUN_MAXREGS);
3476 
3477 	actual_run_size = perfect_run_size;
3478 	actual_nregs = (uint32_t)((actual_run_size - pad_size) /
3479 	    bin_info->reg_interval);
3480 
3481 	/*
3482 	 * Redzones can require enough padding that not even a single region can
3483 	 * fit within the number of pages that would normally be dedicated to a
3484 	 * run for this size class.  Increase the run size until at least one
3485 	 * region fits.
3486 	 */
3487 	while (actual_nregs == 0) {
3488 		assert(config_fill && unlikely(opt_redzone));
3489 
3490 		actual_run_size += PAGE;
3491 		actual_nregs = (uint32_t)((actual_run_size - pad_size) /
3492 		    bin_info->reg_interval);
3493 	}
3494 
3495 	/*
3496 	 * Make sure that the run will fit within an arena chunk.
3497 	 */
3498 	while (actual_run_size > arena_maxrun) {
3499 		actual_run_size -= PAGE;
3500 		actual_nregs = (uint32_t)((actual_run_size - pad_size) /
3501 		    bin_info->reg_interval);
3502 	}
3503 	assert(actual_nregs > 0);
3504 	assert(actual_run_size == s2u(actual_run_size));
3505 
3506 	/* Copy final settings. */
3507 	bin_info->run_size = actual_run_size;
3508 	bin_info->nregs = actual_nregs;
3509 	bin_info->reg0_offset = (uint32_t)(actual_run_size - (actual_nregs *
3510 	    bin_info->reg_interval) - pad_size + bin_info->redzone_size);
3511 
3512 	if (actual_run_size > small_maxrun)
3513 		small_maxrun = actual_run_size;
3514 
3515 	assert(bin_info->reg0_offset - bin_info->redzone_size + (bin_info->nregs
3516 	    * bin_info->reg_interval) + pad_size == bin_info->run_size);
3517 }
3518 
3519 static void
3520 bin_info_init(void)
3521 {
3522 	arena_bin_info_t *bin_info;
3523 
3524 #define	BIN_INFO_INIT_bin_yes(index, size)				\
3525 	bin_info = &arena_bin_info[index];				\
3526 	bin_info->reg_size = size;					\
3527 	bin_info_run_size_calc(bin_info);				\
3528 	bitmap_info_init(&bin_info->bitmap_info, bin_info->nregs);
3529 #define	BIN_INFO_INIT_bin_no(index, size)
3530 #define	SC(index, lg_grp, lg_delta, ndelta, bin, lg_delta_lookup)	\
3531 	BIN_INFO_INIT_bin_##bin(index, (ZU(1)<<lg_grp) + (ZU(ndelta)<<lg_delta))
3532 	SIZE_CLASSES
3533 #undef BIN_INFO_INIT_bin_yes
3534 #undef BIN_INFO_INIT_bin_no
3535 #undef SC
3536 }
3537 
3538 static bool
3539 small_run_size_init(void)
3540 {
3541 
3542 	assert(small_maxrun != 0);
3543 
3544 	small_run_tab = (bool *)base_alloc(sizeof(bool) * (small_maxrun >>
3545 	    LG_PAGE));
3546 	if (small_run_tab == NULL)
3547 		return (true);
3548 
3549 #define	TAB_INIT_bin_yes(index, size) {					\
3550 		arena_bin_info_t *bin_info = &arena_bin_info[index];	\
3551 		small_run_tab[bin_info->run_size >> LG_PAGE] = true;	\
3552 	}
3553 #define	TAB_INIT_bin_no(index, size)
3554 #define	SC(index, lg_grp, lg_delta, ndelta, bin, lg_delta_lookup)	\
3555 	TAB_INIT_bin_##bin(index, (ZU(1)<<lg_grp) + (ZU(ndelta)<<lg_delta))
3556 	SIZE_CLASSES
3557 #undef TAB_INIT_bin_yes
3558 #undef TAB_INIT_bin_no
3559 #undef SC
3560 
3561 	return (false);
3562 }
3563 
3564 static bool
3565 run_quantize_init(void)
3566 {
3567 	unsigned i;
3568 
3569 	run_quantize_max = chunksize + large_pad;
3570 
3571 	run_quantize_floor_tab = (size_t *)base_alloc(sizeof(size_t) *
3572 	    (run_quantize_max >> LG_PAGE));
3573 	if (run_quantize_floor_tab == NULL)
3574 		return (true);
3575 
3576 	run_quantize_ceil_tab = (size_t *)base_alloc(sizeof(size_t) *
3577 	    (run_quantize_max >> LG_PAGE));
3578 	if (run_quantize_ceil_tab == NULL)
3579 		return (true);
3580 
3581 	for (i = 1; i <= run_quantize_max >> LG_PAGE; i++) {
3582 		size_t run_size = i << LG_PAGE;
3583 
3584 		run_quantize_floor_tab[i-1] =
3585 		    run_quantize_floor_compute(run_size);
3586 		run_quantize_ceil_tab[i-1] =
3587 		    run_quantize_ceil_compute(run_size);
3588 	}
3589 
3590 	return (false);
3591 }
3592 
3593 bool
3594 arena_boot(void)
3595 {
3596 	unsigned i;
3597 
3598 	arena_lg_dirty_mult_default_set(opt_lg_dirty_mult);
3599 	arena_decay_time_default_set(opt_decay_time);
3600 
3601 	/*
3602 	 * Compute the header size such that it is large enough to contain the
3603 	 * page map.  The page map is biased to omit entries for the header
3604 	 * itself, so some iteration is necessary to compute the map bias.
3605 	 *
3606 	 * 1) Compute safe header_size and map_bias values that include enough
3607 	 *    space for an unbiased page map.
3608 	 * 2) Refine map_bias based on (1) to omit the header pages in the page
3609 	 *    map.  The resulting map_bias may be one too small.
3610 	 * 3) Refine map_bias based on (2).  The result will be >= the result
3611 	 *    from (2), and will always be correct.
3612 	 */
3613 	map_bias = 0;
3614 	for (i = 0; i < 3; i++) {
3615 		size_t header_size = offsetof(arena_chunk_t, map_bits) +
3616 		    ((sizeof(arena_chunk_map_bits_t) +
3617 		    sizeof(arena_chunk_map_misc_t)) * (chunk_npages-map_bias));
3618 		map_bias = (header_size + PAGE_MASK) >> LG_PAGE;
3619 	}
3620 	assert(map_bias > 0);
3621 
3622 	map_misc_offset = offsetof(arena_chunk_t, map_bits) +
3623 	    sizeof(arena_chunk_map_bits_t) * (chunk_npages-map_bias);
3624 
3625 	arena_maxrun = chunksize - (map_bias << LG_PAGE);
3626 	assert(arena_maxrun > 0);
3627 	large_maxclass = index2size(size2index(chunksize)-1);
3628 	if (large_maxclass > arena_maxrun) {
3629 		/*
3630 		 * For small chunk sizes it's possible for there to be fewer
3631 		 * non-header pages available than are necessary to serve the
3632 		 * size classes just below chunksize.
3633 		 */
3634 		large_maxclass = arena_maxrun;
3635 	}
3636 	assert(large_maxclass > 0);
3637 	nlclasses = size2index(large_maxclass) - size2index(SMALL_MAXCLASS);
3638 	nhclasses = NSIZES - nlclasses - NBINS;
3639 
3640 	bin_info_init();
3641 	if (small_run_size_init())
3642 		return (true);
3643 	if (run_quantize_init())
3644 		return (true);
3645 
3646 	runs_avail_bias = size2index(PAGE);
3647 	runs_avail_nclasses = size2index(run_quantize_max)+1 - runs_avail_bias;
3648 
3649 	return (false);
3650 }
3651 
3652 void
3653 arena_prefork(arena_t *arena)
3654 {
3655 	unsigned i;
3656 
3657 	malloc_mutex_prefork(&arena->lock);
3658 	malloc_mutex_prefork(&arena->huge_mtx);
3659 	malloc_mutex_prefork(&arena->chunks_mtx);
3660 	malloc_mutex_prefork(&arena->node_cache_mtx);
3661 	for (i = 0; i < NBINS; i++)
3662 		malloc_mutex_prefork(&arena->bins[i].lock);
3663 }
3664 
3665 void
3666 arena_postfork_parent(arena_t *arena)
3667 {
3668 	unsigned i;
3669 
3670 	for (i = 0; i < NBINS; i++)
3671 		malloc_mutex_postfork_parent(&arena->bins[i].lock);
3672 	malloc_mutex_postfork_parent(&arena->node_cache_mtx);
3673 	malloc_mutex_postfork_parent(&arena->chunks_mtx);
3674 	malloc_mutex_postfork_parent(&arena->huge_mtx);
3675 	malloc_mutex_postfork_parent(&arena->lock);
3676 }
3677 
3678 void
3679 arena_postfork_child(arena_t *arena)
3680 {
3681 	unsigned i;
3682 
3683 	for (i = 0; i < NBINS; i++)
3684 		malloc_mutex_postfork_child(&arena->bins[i].lock);
3685 	malloc_mutex_postfork_child(&arena->node_cache_mtx);
3686 	malloc_mutex_postfork_child(&arena->chunks_mtx);
3687 	malloc_mutex_postfork_child(&arena->huge_mtx);
3688 	malloc_mutex_postfork_child(&arena->lock);
3689 }
3690