xref: /openbsd-src/sys/kern/subr_pool.c (revision ce1d54409cb423cf325a0a3984b6d36e78bef46f)
1 /*	$OpenBSD: subr_pool.c,v 1.193 2015/09/11 09:26:13 kettenis Exp $	*/
2 /*	$NetBSD: subr_pool.c,v 1.61 2001/09/26 07:14:56 chs Exp $	*/
3 
4 /*-
5  * Copyright (c) 1997, 1999, 2000 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Paul Kranenburg; by Jason R. Thorpe of the Numerical Aerospace
10  * Simulation Facility, NASA Ames Research Center.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/errno.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/pool.h>
40 #include <sys/syslog.h>
41 #include <sys/rwlock.h>
42 #include <sys/sysctl.h>
43 #include <sys/task.h>
44 #include <sys/timeout.h>
45 
46 #include <uvm/uvm_extern.h>
47 
48 /*
49  * Pool resource management utility.
50  *
51  * Memory is allocated in pages which are split into pieces according to
52  * the pool item size. Each page is kept on one of three lists in the
53  * pool structure: `pr_emptypages', `pr_fullpages' and `pr_partpages',
54  * for empty, full and partially-full pages respectively. The individual
55  * pool items are on a linked list headed by `ph_itemlist' in each page
56  * header. The memory for building the page list is either taken from
57  * the allocated pages themselves (for small pool items) or taken from
58  * an internal pool of page headers (`phpool').
59  */
60 
61 /* List of all pools */
62 SIMPLEQ_HEAD(,pool) pool_head = SIMPLEQ_HEAD_INITIALIZER(pool_head);
63 
64 /*
65  * Every pool gets a unique serial number assigned to it. If this counter
66  * wraps, we're screwed, but we shouldn't create so many pools anyway.
67  */
68 unsigned int pool_serial;
69 unsigned int pool_count;
70 
71 /* Lock the previous variables making up the global pool state */
72 struct rwlock pool_lock = RWLOCK_INITIALIZER("pools");
73 
74 /* Private pool for page header structures */
75 struct pool phpool;
76 
77 struct pool_item_header {
78 	/* Page headers */
79 	TAILQ_ENTRY(pool_item_header)
80 				ph_pagelist;	/* pool page list */
81 	XSIMPLEQ_HEAD(,pool_item) ph_itemlist;	/* chunk list for this page */
82 	RB_ENTRY(pool_item_header)
83 				ph_node;	/* Off-page page headers */
84 	int			ph_nmissing;	/* # of chunks in use */
85 	caddr_t			ph_page;	/* this page's address */
86 	caddr_t			ph_colored;	/* page's colored address */
87 	u_long			ph_magic;
88 	int			ph_tick;
89 };
90 #define POOL_MAGICBIT (1 << 3) /* keep away from perturbed low bits */
91 #define POOL_PHPOISON(ph) ISSET((ph)->ph_magic, POOL_MAGICBIT)
92 
93 struct pool_item {
94 	u_long				pi_magic;
95 	XSIMPLEQ_ENTRY(pool_item)	pi_list;
96 };
97 #define POOL_IMAGIC(ph, pi) ((u_long)(pi) ^ (ph)->ph_magic)
98 
99 #ifdef POOL_DEBUG
100 int	pool_debug = 1;
101 #else
102 int	pool_debug = 0;
103 #endif
104 
105 #define POOL_INPGHDR(pp) ((pp)->pr_phoffset != 0)
106 
107 struct pool_item_header *
108 	 pool_p_alloc(struct pool *, int, int *);
109 void	 pool_p_insert(struct pool *, struct pool_item_header *);
110 void	 pool_p_remove(struct pool *, struct pool_item_header *);
111 void	 pool_p_free(struct pool *, struct pool_item_header *);
112 
113 void	 pool_update_curpage(struct pool *);
114 void	*pool_do_get(struct pool *, int, int *);
115 int	 pool_chk_page(struct pool *, struct pool_item_header *, int);
116 int	 pool_chk(struct pool *);
117 void	 pool_get_done(void *, void *);
118 void	 pool_runqueue(struct pool *, int);
119 
120 void	*pool_allocator_alloc(struct pool *, int, int *);
121 void	 pool_allocator_free(struct pool *, void *);
122 
123 /*
124  * The default pool allocator.
125  */
126 void	*pool_page_alloc(struct pool *, int, int *);
127 void	pool_page_free(struct pool *, void *);
128 
129 /*
130  * safe for interrupts; this is the default allocator
131  */
132 struct pool_allocator pool_allocator_single = {
133 	pool_page_alloc,
134 	pool_page_free
135 };
136 
137 void	*pool_multi_alloc(struct pool *, int, int *);
138 void	pool_multi_free(struct pool *, void *);
139 
140 struct pool_allocator pool_allocator_multi = {
141 	pool_multi_alloc,
142 	pool_multi_free
143 };
144 
145 void	*pool_multi_alloc_ni(struct pool *, int, int *);
146 void	pool_multi_free_ni(struct pool *, void *);
147 
148 struct pool_allocator pool_allocator_multi_ni = {
149 	pool_multi_alloc_ni,
150 	pool_multi_free_ni
151 };
152 
153 #ifdef DDB
154 void	 pool_print_pagelist(struct pool_pagelist *, int (*)(const char *, ...)
155 	     __attribute__((__format__(__kprintf__,1,2))));
156 void	 pool_print1(struct pool *, const char *, int (*)(const char *, ...)
157 	     __attribute__((__format__(__kprintf__,1,2))));
158 #endif
159 
160 /* stale page garbage collectors */
161 void	pool_gc_sched(void *);
162 struct timeout pool_gc_tick = TIMEOUT_INITIALIZER(pool_gc_sched, NULL);
163 void	pool_gc_pages(void *);
164 struct task pool_gc_task = TASK_INITIALIZER(pool_gc_pages, NULL);
165 int pool_wait_free = 1;
166 int pool_wait_gc = 8;
167 
168 static inline int
169 phtree_compare(struct pool_item_header *a, struct pool_item_header *b)
170 {
171 	vaddr_t va = (vaddr_t)a->ph_page;
172 	vaddr_t vb = (vaddr_t)b->ph_page;
173 
174 	/* the compares in this order are important for the NFIND to work */
175 	if (vb < va)
176 		return (-1);
177 	if (vb > va)
178 		return (1);
179 
180 	return (0);
181 }
182 
183 RB_PROTOTYPE(phtree, pool_item_header, ph_node, phtree_compare);
184 RB_GENERATE(phtree, pool_item_header, ph_node, phtree_compare);
185 
186 /*
187  * Return the pool page header based on page address.
188  */
189 static inline struct pool_item_header *
190 pr_find_pagehead(struct pool *pp, void *v)
191 {
192 	struct pool_item_header *ph, key;
193 
194 	if (POOL_INPGHDR(pp)) {
195 		caddr_t page;
196 
197 		page = (caddr_t)((vaddr_t)v & pp->pr_pgmask);
198 
199 		return ((struct pool_item_header *)(page + pp->pr_phoffset));
200 	}
201 
202 	key.ph_page = v;
203 	ph = RB_NFIND(phtree, &pp->pr_phtree, &key);
204 	if (ph == NULL)
205 		panic("%s: %s: page header missing", __func__, pp->pr_wchan);
206 
207 	KASSERT(ph->ph_page <= (caddr_t)v);
208 	if (ph->ph_page + pp->pr_pgsize <= (caddr_t)v)
209 		panic("%s: %s: incorrect page", __func__, pp->pr_wchan);
210 
211 	return (ph);
212 }
213 
214 /*
215  * Initialize the given pool resource structure.
216  *
217  * We export this routine to allow other kernel parts to declare
218  * static pools that must be initialized before malloc() is available.
219  */
220 void
221 pool_init(struct pool *pp, size_t size, u_int align, u_int ioff, int flags,
222     const char *wchan, struct pool_allocator *palloc)
223 {
224 	int off = 0, space;
225 	unsigned int pgsize = PAGE_SIZE, items;
226 #ifdef DIAGNOSTIC
227 	struct pool *iter;
228 	KASSERT(ioff == 0);
229 #endif
230 
231 	if (align == 0)
232 		align = ALIGN(1);
233 
234 	if (size < sizeof(struct pool_item))
235 		size = sizeof(struct pool_item);
236 
237 	size = roundup(size, align);
238 
239 	if (palloc == NULL) {
240 		while (size * 8 > pgsize)
241 			pgsize <<= 1;
242 
243 		if (pgsize > PAGE_SIZE) {
244 			palloc = ISSET(flags, PR_WAITOK) ?
245 			    &pool_allocator_multi_ni : &pool_allocator_multi;
246 		} else
247 			palloc = &pool_allocator_single;
248 	} else
249 		pgsize = palloc->pa_pagesz ? palloc->pa_pagesz : PAGE_SIZE;
250 
251 	items = pgsize / size;
252 
253 	/*
254 	 * Decide whether to put the page header off page to avoid
255 	 * wasting too large a part of the page. Off-page page headers
256 	 * go into an RB tree, so we can match a returned item with
257 	 * its header based on the page address.
258 	 */
259 	if (pgsize - (size * items) > sizeof(struct pool_item_header)) {
260 		off = pgsize - sizeof(struct pool_item_header);
261 	} else if (sizeof(struct pool_item_header) * 2 >= size) {
262 		off = pgsize - sizeof(struct pool_item_header);
263 		items = off / size;
264 	}
265 
266 	KASSERT(items > 0);
267 
268 	/*
269 	 * Initialize the pool structure.
270 	 */
271 	memset(pp, 0, sizeof(*pp));
272 	TAILQ_INIT(&pp->pr_emptypages);
273 	TAILQ_INIT(&pp->pr_fullpages);
274 	TAILQ_INIT(&pp->pr_partpages);
275 	pp->pr_curpage = NULL;
276 	pp->pr_npages = 0;
277 	pp->pr_minitems = 0;
278 	pp->pr_minpages = 0;
279 	pp->pr_maxpages = 8;
280 	pp->pr_size = size;
281 	pp->pr_pgsize = pgsize;
282 	pp->pr_pgmask = ~0UL ^ (pgsize - 1);
283 	pp->pr_phoffset = off;
284 	pp->pr_itemsperpage = items;
285 	pp->pr_wchan = wchan;
286 	pp->pr_alloc = palloc;
287 	pp->pr_nitems = 0;
288 	pp->pr_nout = 0;
289 	pp->pr_hardlimit = UINT_MAX;
290 	pp->pr_hardlimit_warning = NULL;
291 	pp->pr_hardlimit_ratecap.tv_sec = 0;
292 	pp->pr_hardlimit_ratecap.tv_usec = 0;
293 	pp->pr_hardlimit_warning_last.tv_sec = 0;
294 	pp->pr_hardlimit_warning_last.tv_usec = 0;
295 	RB_INIT(&pp->pr_phtree);
296 
297 	/*
298 	 * Use the space between the chunks and the page header
299 	 * for cache coloring.
300 	 */
301 	space = POOL_INPGHDR(pp) ? pp->pr_phoffset : pp->pr_pgsize;
302 	space -= pp->pr_itemsperpage * pp->pr_size;
303 	pp->pr_align = align;
304 	pp->pr_maxcolors = (space / align) + 1;
305 
306 	pp->pr_nget = 0;
307 	pp->pr_nfail = 0;
308 	pp->pr_nput = 0;
309 	pp->pr_npagealloc = 0;
310 	pp->pr_npagefree = 0;
311 	pp->pr_hiwat = 0;
312 	pp->pr_nidle = 0;
313 
314 	pp->pr_ipl = -1;
315 	mtx_init(&pp->pr_mtx, IPL_NONE);
316 	mtx_init(&pp->pr_requests_mtx, IPL_NONE);
317 	TAILQ_INIT(&pp->pr_requests);
318 
319 	if (phpool.pr_size == 0) {
320 		pool_init(&phpool, sizeof(struct pool_item_header), 0, 0,
321 		    0, "phpool", NULL);
322 		pool_setipl(&phpool, IPL_HIGH);
323 
324 		/* make sure phpool wont "recurse" */
325 		KASSERT(POOL_INPGHDR(&phpool));
326 	}
327 
328 	/* pglistalloc/constraint parameters */
329 	pp->pr_crange = &kp_dirty;
330 
331 	/* Insert this into the list of all pools. */
332 	rw_enter_write(&pool_lock);
333 #ifdef DIAGNOSTIC
334 	SIMPLEQ_FOREACH(iter, &pool_head, pr_poollist) {
335 		if (iter == pp)
336 			panic("%s: pool %s already on list", __func__, wchan);
337 	}
338 #endif
339 
340 	pp->pr_serial = ++pool_serial;
341 	if (pool_serial == 0)
342 		panic("%s: too much uptime", __func__);
343 
344 	SIMPLEQ_INSERT_HEAD(&pool_head, pp, pr_poollist);
345 	pool_count++;
346 	rw_exit_write(&pool_lock);
347 }
348 
349 void
350 pool_setipl(struct pool *pp, int ipl)
351 {
352 	pp->pr_ipl = ipl;
353 	mtx_init(&pp->pr_mtx, ipl);
354 	mtx_init(&pp->pr_requests_mtx, ipl);
355 }
356 
357 /*
358  * Decommission a pool resource.
359  */
360 void
361 pool_destroy(struct pool *pp)
362 {
363 	struct pool_item_header *ph;
364 	struct pool *prev, *iter;
365 
366 #ifdef DIAGNOSTIC
367 	if (pp->pr_nout != 0)
368 		panic("%s: pool busy: still out: %u", __func__, pp->pr_nout);
369 #endif
370 
371 	/* Remove from global pool list */
372 	rw_enter_write(&pool_lock);
373 	pool_count--;
374 	if (pp == SIMPLEQ_FIRST(&pool_head))
375 		SIMPLEQ_REMOVE_HEAD(&pool_head, pr_poollist);
376 	else {
377 		prev = SIMPLEQ_FIRST(&pool_head);
378 		SIMPLEQ_FOREACH(iter, &pool_head, pr_poollist) {
379 			if (iter == pp) {
380 				SIMPLEQ_REMOVE_AFTER(&pool_head, prev,
381 				    pr_poollist);
382 				break;
383 			}
384 			prev = iter;
385 		}
386 	}
387 	rw_exit_write(&pool_lock);
388 
389 	/* Remove all pages */
390 	while ((ph = TAILQ_FIRST(&pp->pr_emptypages)) != NULL) {
391 		mtx_enter(&pp->pr_mtx);
392 		pool_p_remove(pp, ph);
393 		mtx_leave(&pp->pr_mtx);
394 		pool_p_free(pp, ph);
395 	}
396 	KASSERT(TAILQ_EMPTY(&pp->pr_fullpages));
397 	KASSERT(TAILQ_EMPTY(&pp->pr_partpages));
398 }
399 
400 void
401 pool_request_init(struct pool_request *pr,
402     void (*handler)(void *, void *), void *cookie)
403 {
404 	pr->pr_handler = handler;
405 	pr->pr_cookie = cookie;
406 	pr->pr_item = NULL;
407 }
408 
409 void
410 pool_request(struct pool *pp, struct pool_request *pr)
411 {
412 	mtx_enter(&pp->pr_requests_mtx);
413 	TAILQ_INSERT_TAIL(&pp->pr_requests, pr, pr_entry);
414 	pool_runqueue(pp, PR_NOWAIT);
415 	mtx_leave(&pp->pr_requests_mtx);
416 }
417 
418 struct pool_get_memory {
419 	struct mutex mtx;
420 	void * volatile v;
421 };
422 
423 /*
424  * Grab an item from the pool.
425  */
426 void *
427 pool_get(struct pool *pp, int flags)
428 {
429 	void *v = NULL;
430 	int slowdown = 0;
431 
432 	KASSERT(flags & (PR_WAITOK | PR_NOWAIT));
433 
434 
435 	mtx_enter(&pp->pr_mtx);
436 	if (pp->pr_nout >= pp->pr_hardlimit) {
437 		if (ISSET(flags, PR_NOWAIT|PR_LIMITFAIL))
438 			goto fail;
439 	} else if ((v = pool_do_get(pp, flags, &slowdown)) == NULL) {
440 		if (ISSET(flags, PR_NOWAIT))
441 			goto fail;
442 	}
443 	mtx_leave(&pp->pr_mtx);
444 
445 	if (slowdown && ISSET(flags, PR_WAITOK))
446 		yield();
447 
448 	if (v == NULL) {
449 		struct pool_get_memory mem = {
450 		    MUTEX_INITIALIZER((pp->pr_ipl == -1) ?
451 		    IPL_NONE : pp->pr_ipl), NULL };
452 		struct pool_request pr;
453 
454 		pool_request_init(&pr, pool_get_done, &mem);
455 		pool_request(pp, &pr);
456 
457 		mtx_enter(&mem.mtx);
458 		while (mem.v == NULL)
459 			msleep(&mem, &mem.mtx, PSWP, pp->pr_wchan, 0);
460 		mtx_leave(&mem.mtx);
461 
462 		v = mem.v;
463 	}
464 
465 	if (ISSET(flags, PR_ZERO))
466 		memset(v, 0, pp->pr_size);
467 
468 	return (v);
469 
470 fail:
471 	pp->pr_nfail++;
472 	mtx_leave(&pp->pr_mtx);
473 	return (NULL);
474 }
475 
476 void
477 pool_get_done(void *xmem, void *v)
478 {
479 	struct pool_get_memory *mem = xmem;
480 
481 	mtx_enter(&mem->mtx);
482 	mem->v = v;
483 	mtx_leave(&mem->mtx);
484 
485 	wakeup_one(mem);
486 }
487 
488 void
489 pool_runqueue(struct pool *pp, int flags)
490 {
491 	struct pool_requests prl = TAILQ_HEAD_INITIALIZER(prl);
492 	struct pool_request *pr;
493 
494 	MUTEX_ASSERT_UNLOCKED(&pp->pr_mtx);
495 	MUTEX_ASSERT_LOCKED(&pp->pr_requests_mtx);
496 
497 	if (pp->pr_requesting++)
498 		return;
499 
500 	do {
501 		pp->pr_requesting = 1;
502 
503 		/* no TAILQ_JOIN? :( */
504 		while ((pr = TAILQ_FIRST(&pp->pr_requests)) != NULL) {
505 			TAILQ_REMOVE(&pp->pr_requests, pr, pr_entry);
506 			TAILQ_INSERT_TAIL(&prl, pr, pr_entry);
507 		}
508 		if (TAILQ_EMPTY(&prl))
509 			continue;
510 
511 		mtx_leave(&pp->pr_requests_mtx);
512 
513 		mtx_enter(&pp->pr_mtx);
514 		pr = TAILQ_FIRST(&prl);
515 		while (pr != NULL) {
516 			int slowdown = 0;
517 
518 			if (pp->pr_nout >= pp->pr_hardlimit)
519 				break;
520 
521 			pr->pr_item = pool_do_get(pp, flags, &slowdown);
522 			if (pr->pr_item == NULL) /* || slowdown ? */
523 				break;
524 
525 			pr = TAILQ_NEXT(pr, pr_entry);
526 		}
527 		mtx_leave(&pp->pr_mtx);
528 
529 		while ((pr = TAILQ_FIRST(&prl)) != NULL &&
530 		    pr->pr_item != NULL) {
531 			TAILQ_REMOVE(&prl, pr, pr_entry);
532 			(*pr->pr_handler)(pr->pr_cookie, pr->pr_item);
533 		}
534 
535 		mtx_enter(&pp->pr_requests_mtx);
536 	} while (--pp->pr_requesting);
537 
538 	/* no TAILQ_JOIN :( */
539 	while ((pr = TAILQ_FIRST(&prl)) != NULL) {
540 		TAILQ_REMOVE(&prl, pr, pr_entry);
541 		TAILQ_INSERT_TAIL(&pp->pr_requests, pr, pr_entry);
542 	}
543 }
544 
545 void *
546 pool_do_get(struct pool *pp, int flags, int *slowdown)
547 {
548 	struct pool_item *pi;
549 	struct pool_item_header *ph;
550 
551 	MUTEX_ASSERT_LOCKED(&pp->pr_mtx);
552 
553 	if (pp->pr_ipl != -1)
554 		splassert(pp->pr_ipl);
555 
556 	/*
557 	 * Account for this item now to avoid races if we need to give up
558 	 * pr_mtx to allocate a page.
559 	 */
560 	pp->pr_nout++;
561 
562 	if (pp->pr_curpage == NULL) {
563 		mtx_leave(&pp->pr_mtx);
564 		ph = pool_p_alloc(pp, flags, slowdown);
565 		mtx_enter(&pp->pr_mtx);
566 
567 		if (ph == NULL) {
568 			pp->pr_nout--;
569 			return (NULL);
570 		}
571 
572 		pool_p_insert(pp, ph);
573 	}
574 
575 	ph = pp->pr_curpage;
576 	pi = XSIMPLEQ_FIRST(&ph->ph_itemlist);
577 	if (__predict_false(pi == NULL))
578 		panic("%s: %s: page empty", __func__, pp->pr_wchan);
579 
580 	if (__predict_false(pi->pi_magic != POOL_IMAGIC(ph, pi))) {
581 		panic("%s: %s free list modified: "
582 		    "page %p; item addr %p; offset 0x%x=0x%lx != 0x%lx",
583 		    __func__, pp->pr_wchan, ph->ph_page, pi,
584 		    0, pi->pi_magic, POOL_IMAGIC(ph, pi));
585 	}
586 
587 	XSIMPLEQ_REMOVE_HEAD(&ph->ph_itemlist, pi_list);
588 
589 #ifdef DIAGNOSTIC
590 	if (pool_debug && POOL_PHPOISON(ph)) {
591 		size_t pidx;
592 		uint32_t pval;
593 		if (poison_check(pi + 1, pp->pr_size - sizeof(*pi),
594 		    &pidx, &pval)) {
595 			int *ip = (int *)(pi + 1);
596 			panic("%s: %s free list modified: "
597 			    "page %p; item addr %p; offset 0x%zx=0x%x",
598 			    __func__, pp->pr_wchan, ph->ph_page, pi,
599 			    pidx * sizeof(int), ip[pidx]);
600 		}
601 	}
602 #endif /* DIAGNOSTIC */
603 
604 	if (ph->ph_nmissing++ == 0) {
605 		/*
606 		 * This page was previously empty.  Move it to the list of
607 		 * partially-full pages.  This page is already curpage.
608 		 */
609 		TAILQ_REMOVE(&pp->pr_emptypages, ph, ph_pagelist);
610 		TAILQ_INSERT_TAIL(&pp->pr_partpages, ph, ph_pagelist);
611 
612 		pp->pr_nidle--;
613 	}
614 
615 	if (ph->ph_nmissing == pp->pr_itemsperpage) {
616 		/*
617 		 * This page is now full.  Move it to the full list
618 		 * and select a new current page.
619 		 */
620 		TAILQ_REMOVE(&pp->pr_partpages, ph, ph_pagelist);
621 		TAILQ_INSERT_TAIL(&pp->pr_fullpages, ph, ph_pagelist);
622 		pool_update_curpage(pp);
623 	}
624 
625 	pp->pr_nget++;
626 
627 	return (pi);
628 }
629 
630 /*
631  * Return resource to the pool.
632  */
633 void
634 pool_put(struct pool *pp, void *v)
635 {
636 	struct pool_item *pi = v;
637 	struct pool_item_header *ph, *freeph = NULL;
638 
639 #ifdef DIAGNOSTIC
640 	if (v == NULL)
641 		panic("%s: NULL item", __func__);
642 #endif
643 
644 	mtx_enter(&pp->pr_mtx);
645 
646 	if (pp->pr_ipl != -1)
647 		splassert(pp->pr_ipl);
648 
649 	ph = pr_find_pagehead(pp, v);
650 
651 #ifdef DIAGNOSTIC
652 	if (pool_debug) {
653 		struct pool_item *qi;
654 		XSIMPLEQ_FOREACH(qi, &ph->ph_itemlist, pi_list) {
655 			if (pi == qi) {
656 				panic("%s: %s: double pool_put: %p", __func__,
657 				    pp->pr_wchan, pi);
658 			}
659 		}
660 	}
661 #endif /* DIAGNOSTIC */
662 
663 	pi->pi_magic = POOL_IMAGIC(ph, pi);
664 	XSIMPLEQ_INSERT_HEAD(&ph->ph_itemlist, pi, pi_list);
665 #ifdef DIAGNOSTIC
666 	if (POOL_PHPOISON(ph))
667 		poison_mem(pi + 1, pp->pr_size - sizeof(*pi));
668 #endif /* DIAGNOSTIC */
669 
670 	if (ph->ph_nmissing-- == pp->pr_itemsperpage) {
671 		/*
672 		 * The page was previously completely full, move it to the
673 		 * partially-full list.
674 		 */
675 		TAILQ_REMOVE(&pp->pr_fullpages, ph, ph_pagelist);
676 		TAILQ_INSERT_TAIL(&pp->pr_partpages, ph, ph_pagelist);
677 	}
678 
679 	if (ph->ph_nmissing == 0) {
680 		/*
681 		 * The page is now empty, so move it to the empty page list.
682 	 	 */
683 		pp->pr_nidle++;
684 
685 		ph->ph_tick = ticks;
686 		TAILQ_REMOVE(&pp->pr_partpages, ph, ph_pagelist);
687 		TAILQ_INSERT_TAIL(&pp->pr_emptypages, ph, ph_pagelist);
688 		pool_update_curpage(pp);
689 	}
690 
691 	pp->pr_nout--;
692 	pp->pr_nput++;
693 
694 	/* is it time to free a page? */
695 	if (pp->pr_nidle > pp->pr_maxpages &&
696 	    (ph = TAILQ_FIRST(&pp->pr_emptypages)) != NULL &&
697 	    (ticks - ph->ph_tick) > (hz * pool_wait_free)) {
698 		freeph = ph;
699 		pool_p_remove(pp, freeph);
700 	}
701 	mtx_leave(&pp->pr_mtx);
702 
703 	if (freeph != NULL)
704 		pool_p_free(pp, freeph);
705 
706 	mtx_enter(&pp->pr_requests_mtx);
707 	pool_runqueue(pp, PR_NOWAIT);
708 	mtx_leave(&pp->pr_requests_mtx);
709 }
710 
711 /*
712  * Add N items to the pool.
713  */
714 int
715 pool_prime(struct pool *pp, int n)
716 {
717 	struct pool_pagelist pl = TAILQ_HEAD_INITIALIZER(pl);
718 	struct pool_item_header *ph;
719 	int newpages;
720 
721 	newpages = roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
722 
723 	while (newpages-- > 0) {
724 		int slowdown = 0;
725 
726 		ph = pool_p_alloc(pp, PR_NOWAIT, &slowdown);
727 		if (ph == NULL) /* or slowdown? */
728 			break;
729 
730 		TAILQ_INSERT_TAIL(&pl, ph, ph_pagelist);
731 	}
732 
733 	mtx_enter(&pp->pr_mtx);
734 	while ((ph = TAILQ_FIRST(&pl)) != NULL) {
735 		TAILQ_REMOVE(&pl, ph, ph_pagelist);
736 		pool_p_insert(pp, ph);
737 	}
738 	mtx_leave(&pp->pr_mtx);
739 
740 	return (0);
741 }
742 
743 struct pool_item_header *
744 pool_p_alloc(struct pool *pp, int flags, int *slowdown)
745 {
746 	struct pool_item_header *ph;
747 	struct pool_item *pi;
748 	caddr_t addr;
749 	int n;
750 
751 	MUTEX_ASSERT_UNLOCKED(&pp->pr_mtx);
752 	KASSERT(pp->pr_size >= sizeof(*pi));
753 
754 	addr = pool_allocator_alloc(pp, flags, slowdown);
755 	if (addr == NULL)
756 		return (NULL);
757 
758 	if (POOL_INPGHDR(pp))
759 		ph = (struct pool_item_header *)(addr + pp->pr_phoffset);
760 	else {
761 		ph = pool_get(&phpool, flags);
762 		if (ph == NULL) {
763 			pool_allocator_free(pp, addr);
764 			return (NULL);
765 		}
766 	}
767 
768 	XSIMPLEQ_INIT(&ph->ph_itemlist);
769 	ph->ph_page = addr;
770 	addr += pp->pr_align * (pp->pr_npagealloc % pp->pr_maxcolors);
771 	ph->ph_colored = addr;
772 	ph->ph_nmissing = 0;
773 	arc4random_buf(&ph->ph_magic, sizeof(ph->ph_magic));
774 #ifdef DIAGNOSTIC
775 	/* use a bit in ph_magic to record if we poison page items */
776 	if (pool_debug)
777 		SET(ph->ph_magic, POOL_MAGICBIT);
778 	else
779 		CLR(ph->ph_magic, POOL_MAGICBIT);
780 #endif /* DIAGNOSTIC */
781 
782 	n = pp->pr_itemsperpage;
783 	while (n--) {
784 		pi = (struct pool_item *)addr;
785 		pi->pi_magic = POOL_IMAGIC(ph, pi);
786 		XSIMPLEQ_INSERT_TAIL(&ph->ph_itemlist, pi, pi_list);
787 
788 #ifdef DIAGNOSTIC
789 		if (POOL_PHPOISON(ph))
790 			poison_mem(pi + 1, pp->pr_size - sizeof(*pi));
791 #endif /* DIAGNOSTIC */
792 
793 		addr += pp->pr_size;
794 	}
795 
796 	return (ph);
797 }
798 
799 void
800 pool_p_free(struct pool *pp, struct pool_item_header *ph)
801 {
802 	struct pool_item *pi;
803 
804 	MUTEX_ASSERT_UNLOCKED(&pp->pr_mtx);
805 	KASSERT(ph->ph_nmissing == 0);
806 
807 	XSIMPLEQ_FOREACH(pi, &ph->ph_itemlist, pi_list) {
808 		if (__predict_false(pi->pi_magic != POOL_IMAGIC(ph, pi))) {
809 			panic("%s: %s free list modified: "
810 			    "page %p; item addr %p; offset 0x%x=0x%lx",
811 			    __func__, pp->pr_wchan, ph->ph_page, pi,
812 			    0, pi->pi_magic);
813 		}
814 
815 #ifdef DIAGNOSTIC
816 		if (POOL_PHPOISON(ph)) {
817 			size_t pidx;
818 			uint32_t pval;
819 			if (poison_check(pi + 1, pp->pr_size - sizeof(*pi),
820 			    &pidx, &pval)) {
821 				int *ip = (int *)(pi + 1);
822 				panic("%s: %s free list modified: "
823 				    "page %p; item addr %p; offset 0x%zx=0x%x",
824 				    __func__, pp->pr_wchan, ph->ph_page, pi,
825 				    pidx * sizeof(int), ip[pidx]);
826 			}
827 		}
828 #endif
829 	}
830 
831 	pool_allocator_free(pp, ph->ph_page);
832 
833 	if (!POOL_INPGHDR(pp))
834 		pool_put(&phpool, ph);
835 }
836 
837 void
838 pool_p_insert(struct pool *pp, struct pool_item_header *ph)
839 {
840 	MUTEX_ASSERT_LOCKED(&pp->pr_mtx);
841 
842 	/* If the pool was depleted, point at the new page */
843 	if (pp->pr_curpage == NULL)
844 		pp->pr_curpage = ph;
845 
846 	TAILQ_INSERT_TAIL(&pp->pr_emptypages, ph, ph_pagelist);
847 	if (!POOL_INPGHDR(pp))
848 		RB_INSERT(phtree, &pp->pr_phtree, ph);
849 
850 	pp->pr_nitems += pp->pr_itemsperpage;
851 	pp->pr_nidle++;
852 
853 	pp->pr_npagealloc++;
854 	if (++pp->pr_npages > pp->pr_hiwat)
855 		pp->pr_hiwat = pp->pr_npages;
856 }
857 
858 void
859 pool_p_remove(struct pool *pp, struct pool_item_header *ph)
860 {
861 	MUTEX_ASSERT_LOCKED(&pp->pr_mtx);
862 
863 	pp->pr_npagefree++;
864 	pp->pr_npages--;
865 	pp->pr_nidle--;
866 	pp->pr_nitems -= pp->pr_itemsperpage;
867 
868 	if (!POOL_INPGHDR(pp))
869 		RB_REMOVE(phtree, &pp->pr_phtree, ph);
870 	TAILQ_REMOVE(&pp->pr_emptypages, ph, ph_pagelist);
871 
872 	pool_update_curpage(pp);
873 }
874 
875 void
876 pool_update_curpage(struct pool *pp)
877 {
878 	pp->pr_curpage = TAILQ_LAST(&pp->pr_partpages, pool_pagelist);
879 	if (pp->pr_curpage == NULL) {
880 		pp->pr_curpage = TAILQ_LAST(&pp->pr_emptypages, pool_pagelist);
881 	}
882 }
883 
884 void
885 pool_setlowat(struct pool *pp, int n)
886 {
887 	int prime = 0;
888 
889 	mtx_enter(&pp->pr_mtx);
890 	pp->pr_minitems = n;
891 	pp->pr_minpages = (n == 0)
892 		? 0
893 		: roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
894 
895 	if (pp->pr_nitems < n)
896 		prime = n - pp->pr_nitems;
897 	mtx_leave(&pp->pr_mtx);
898 
899 	if (prime > 0)
900 		pool_prime(pp, prime);
901 }
902 
903 void
904 pool_sethiwat(struct pool *pp, int n)
905 {
906 	pp->pr_maxpages = (n == 0)
907 		? 0
908 		: roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
909 }
910 
911 int
912 pool_sethardlimit(struct pool *pp, u_int n, const char *warnmsg, int ratecap)
913 {
914 	int error = 0;
915 
916 	if (n < pp->pr_nout) {
917 		error = EINVAL;
918 		goto done;
919 	}
920 
921 	pp->pr_hardlimit = n;
922 	pp->pr_hardlimit_warning = warnmsg;
923 	pp->pr_hardlimit_ratecap.tv_sec = ratecap;
924 	pp->pr_hardlimit_warning_last.tv_sec = 0;
925 	pp->pr_hardlimit_warning_last.tv_usec = 0;
926 
927 done:
928 	return (error);
929 }
930 
931 void
932 pool_set_constraints(struct pool *pp, const struct kmem_pa_mode *mode)
933 {
934 	pp->pr_crange = mode;
935 }
936 
937 /*
938  * Release all complete pages that have not been used recently.
939  *
940  * Returns non-zero if any pages have been reclaimed.
941  */
942 int
943 pool_reclaim(struct pool *pp)
944 {
945 	struct pool_item_header *ph, *phnext;
946 	struct pool_pagelist pl = TAILQ_HEAD_INITIALIZER(pl);
947 
948 	mtx_enter(&pp->pr_mtx);
949 	for (ph = TAILQ_FIRST(&pp->pr_emptypages); ph != NULL; ph = phnext) {
950 		phnext = TAILQ_NEXT(ph, ph_pagelist);
951 
952 		/* Check our minimum page claim */
953 		if (pp->pr_npages <= pp->pr_minpages)
954 			break;
955 
956 		/*
957 		 * If freeing this page would put us below
958 		 * the low water mark, stop now.
959 		 */
960 		if ((pp->pr_nitems - pp->pr_itemsperpage) <
961 		    pp->pr_minitems)
962 			break;
963 
964 		pool_p_remove(pp, ph);
965 		TAILQ_INSERT_TAIL(&pl, ph, ph_pagelist);
966 	}
967 	mtx_leave(&pp->pr_mtx);
968 
969 	if (TAILQ_EMPTY(&pl))
970 		return (0);
971 
972 	while ((ph = TAILQ_FIRST(&pl)) != NULL) {
973 		TAILQ_REMOVE(&pl, ph, ph_pagelist);
974 		pool_p_free(pp, ph);
975 	}
976 
977 	return (1);
978 }
979 
980 /*
981  * Release all complete pages that have not been used recently
982  * from all pools.
983  */
984 void
985 pool_reclaim_all(void)
986 {
987 	struct pool	*pp;
988 
989 	rw_enter_read(&pool_lock);
990 	SIMPLEQ_FOREACH(pp, &pool_head, pr_poollist)
991 		pool_reclaim(pp);
992 	rw_exit_read(&pool_lock);
993 }
994 
995 #ifdef DDB
996 #include <machine/db_machdep.h>
997 #include <ddb/db_output.h>
998 
999 /*
1000  * Diagnostic helpers.
1001  */
1002 void
1003 pool_printit(struct pool *pp, const char *modif,
1004     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
1005 {
1006 	pool_print1(pp, modif, pr);
1007 }
1008 
1009 void
1010 pool_print_pagelist(struct pool_pagelist *pl,
1011     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
1012 {
1013 	struct pool_item_header *ph;
1014 	struct pool_item *pi;
1015 
1016 	TAILQ_FOREACH(ph, pl, ph_pagelist) {
1017 		(*pr)("\t\tpage %p, color %p, nmissing %d\n",
1018 		    ph->ph_page, ph->ph_colored, ph->ph_nmissing);
1019 		XSIMPLEQ_FOREACH(pi, &ph->ph_itemlist, pi_list) {
1020 			if (pi->pi_magic != POOL_IMAGIC(ph, pi)) {
1021 				(*pr)("\t\t\titem %p, magic 0x%lx\n",
1022 				    pi, pi->pi_magic);
1023 			}
1024 		}
1025 	}
1026 }
1027 
1028 void
1029 pool_print1(struct pool *pp, const char *modif,
1030     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
1031 {
1032 	struct pool_item_header *ph;
1033 	int print_pagelist = 0;
1034 	char c;
1035 
1036 	while ((c = *modif++) != '\0') {
1037 		if (c == 'p')
1038 			print_pagelist = 1;
1039 		modif++;
1040 	}
1041 
1042 	(*pr)("POOL %s: size %u maxcolors %u\n", pp->pr_wchan, pp->pr_size,
1043 	    pp->pr_maxcolors);
1044 	(*pr)("\talloc %p\n", pp->pr_alloc);
1045 	(*pr)("\tminitems %u, minpages %u, maxpages %u, npages %u\n",
1046 	    pp->pr_minitems, pp->pr_minpages, pp->pr_maxpages, pp->pr_npages);
1047 	(*pr)("\titemsperpage %u, nitems %u, nout %u, hardlimit %u\n",
1048 	    pp->pr_itemsperpage, pp->pr_nitems, pp->pr_nout, pp->pr_hardlimit);
1049 
1050 	(*pr)("\n\tnget %lu, nfail %lu, nput %lu\n",
1051 	    pp->pr_nget, pp->pr_nfail, pp->pr_nput);
1052 	(*pr)("\tnpagealloc %lu, npagefree %lu, hiwat %u, nidle %lu\n",
1053 	    pp->pr_npagealloc, pp->pr_npagefree, pp->pr_hiwat, pp->pr_nidle);
1054 
1055 	if (print_pagelist == 0)
1056 		return;
1057 
1058 	if ((ph = TAILQ_FIRST(&pp->pr_emptypages)) != NULL)
1059 		(*pr)("\n\tempty page list:\n");
1060 	pool_print_pagelist(&pp->pr_emptypages, pr);
1061 	if ((ph = TAILQ_FIRST(&pp->pr_fullpages)) != NULL)
1062 		(*pr)("\n\tfull page list:\n");
1063 	pool_print_pagelist(&pp->pr_fullpages, pr);
1064 	if ((ph = TAILQ_FIRST(&pp->pr_partpages)) != NULL)
1065 		(*pr)("\n\tpartial-page list:\n");
1066 	pool_print_pagelist(&pp->pr_partpages, pr);
1067 
1068 	if (pp->pr_curpage == NULL)
1069 		(*pr)("\tno current page\n");
1070 	else
1071 		(*pr)("\tcurpage %p\n", pp->pr_curpage->ph_page);
1072 }
1073 
1074 void
1075 db_show_all_pools(db_expr_t expr, int haddr, db_expr_t count, char *modif)
1076 {
1077 	struct pool *pp;
1078 	char maxp[16];
1079 	int ovflw;
1080 	char mode;
1081 
1082 	mode = modif[0];
1083 	if (mode != '\0' && mode != 'a') {
1084 		db_printf("usage: show all pools [/a]\n");
1085 		return;
1086 	}
1087 
1088 	if (mode == '\0')
1089 		db_printf("%-10s%4s%9s%5s%9s%6s%6s%6s%6s%6s%6s%5s\n",
1090 		    "Name",
1091 		    "Size",
1092 		    "Requests",
1093 		    "Fail",
1094 		    "Releases",
1095 		    "Pgreq",
1096 		    "Pgrel",
1097 		    "Npage",
1098 		    "Hiwat",
1099 		    "Minpg",
1100 		    "Maxpg",
1101 		    "Idle");
1102 	else
1103 		db_printf("%-12s %18s %18s\n",
1104 		    "Name", "Address", "Allocator");
1105 
1106 	SIMPLEQ_FOREACH(pp, &pool_head, pr_poollist) {
1107 		if (mode == 'a') {
1108 			db_printf("%-12s %18p %18p\n", pp->pr_wchan, pp,
1109 			    pp->pr_alloc);
1110 			continue;
1111 		}
1112 
1113 		if (!pp->pr_nget)
1114 			continue;
1115 
1116 		if (pp->pr_maxpages == UINT_MAX)
1117 			snprintf(maxp, sizeof maxp, "inf");
1118 		else
1119 			snprintf(maxp, sizeof maxp, "%u", pp->pr_maxpages);
1120 
1121 #define PRWORD(ovflw, fmt, width, fixed, val) do {	\
1122 	(ovflw) += db_printf((fmt),			\
1123 	    (width) - (fixed) - (ovflw) > 0 ?		\
1124 	    (width) - (fixed) - (ovflw) : 0,		\
1125 	    (val)) - (width);				\
1126 	if ((ovflw) < 0)				\
1127 		(ovflw) = 0;				\
1128 } while (/* CONSTCOND */0)
1129 
1130 		ovflw = 0;
1131 		PRWORD(ovflw, "%-*s", 10, 0, pp->pr_wchan);
1132 		PRWORD(ovflw, " %*u", 4, 1, pp->pr_size);
1133 		PRWORD(ovflw, " %*lu", 9, 1, pp->pr_nget);
1134 		PRWORD(ovflw, " %*lu", 5, 1, pp->pr_nfail);
1135 		PRWORD(ovflw, " %*lu", 9, 1, pp->pr_nput);
1136 		PRWORD(ovflw, " %*lu", 6, 1, pp->pr_npagealloc);
1137 		PRWORD(ovflw, " %*lu", 6, 1, pp->pr_npagefree);
1138 		PRWORD(ovflw, " %*d", 6, 1, pp->pr_npages);
1139 		PRWORD(ovflw, " %*d", 6, 1, pp->pr_hiwat);
1140 		PRWORD(ovflw, " %*d", 6, 1, pp->pr_minpages);
1141 		PRWORD(ovflw, " %*s", 6, 1, maxp);
1142 		PRWORD(ovflw, " %*lu\n", 5, 1, pp->pr_nidle);
1143 
1144 		pool_chk(pp);
1145 	}
1146 }
1147 #endif /* DDB */
1148 
1149 #if defined(POOL_DEBUG) || defined(DDB)
1150 int
1151 pool_chk_page(struct pool *pp, struct pool_item_header *ph, int expected)
1152 {
1153 	struct pool_item *pi;
1154 	caddr_t page;
1155 	int n;
1156 	const char *label = pp->pr_wchan;
1157 
1158 	page = (caddr_t)((u_long)ph & pp->pr_pgmask);
1159 	if (page != ph->ph_page && POOL_INPGHDR(pp)) {
1160 		printf("%s: ", label);
1161 		printf("pool(%p:%s): page inconsistency: page %p; "
1162 		    "at page head addr %p (p %p)\n",
1163 		    pp, pp->pr_wchan, ph->ph_page, ph, page);
1164 		return 1;
1165 	}
1166 
1167 	for (pi = XSIMPLEQ_FIRST(&ph->ph_itemlist), n = 0;
1168 	     pi != NULL;
1169 	     pi = XSIMPLEQ_NEXT(&ph->ph_itemlist, pi, pi_list), n++) {
1170 		if ((caddr_t)pi < ph->ph_page ||
1171 		    (caddr_t)pi >= ph->ph_page + pp->pr_pgsize) {
1172 			printf("%s: ", label);
1173 			printf("pool(%p:%s): page inconsistency: page %p;"
1174 			    " item ordinal %d; addr %p\n", pp,
1175 			    pp->pr_wchan, ph->ph_page, n, pi);
1176 			return (1);
1177 		}
1178 
1179 		if (pi->pi_magic != POOL_IMAGIC(ph, pi)) {
1180 			printf("%s: ", label);
1181 			printf("pool(%p:%s): free list modified: "
1182 			    "page %p; item ordinal %d; addr %p "
1183 			    "(p %p); offset 0x%x=0x%lx\n",
1184 			    pp, pp->pr_wchan, ph->ph_page, n, pi, page,
1185 			    0, pi->pi_magic);
1186 		}
1187 
1188 #ifdef DIAGNOSTIC
1189 		if (POOL_PHPOISON(ph)) {
1190 			size_t pidx;
1191 			uint32_t pval;
1192 			if (poison_check(pi + 1, pp->pr_size - sizeof(*pi),
1193 			    &pidx, &pval)) {
1194 				int *ip = (int *)(pi + 1);
1195 				printf("pool(%s): free list modified: "
1196 				    "page %p; item ordinal %d; addr %p "
1197 				    "(p %p); offset 0x%zx=0x%x\n",
1198 				    pp->pr_wchan, ph->ph_page, n, pi,
1199 				    page, pidx * sizeof(int), ip[pidx]);
1200 			}
1201 		}
1202 #endif /* DIAGNOSTIC */
1203 	}
1204 	if (n + ph->ph_nmissing != pp->pr_itemsperpage) {
1205 		printf("pool(%p:%s): page inconsistency: page %p;"
1206 		    " %d on list, %d missing, %d items per page\n", pp,
1207 		    pp->pr_wchan, ph->ph_page, n, ph->ph_nmissing,
1208 		    pp->pr_itemsperpage);
1209 		return 1;
1210 	}
1211 	if (expected >= 0 && n != expected) {
1212 		printf("pool(%p:%s): page inconsistency: page %p;"
1213 		    " %d on list, %d missing, %d expected\n", pp,
1214 		    pp->pr_wchan, ph->ph_page, n, ph->ph_nmissing,
1215 		    expected);
1216 		return 1;
1217 	}
1218 	return 0;
1219 }
1220 
1221 int
1222 pool_chk(struct pool *pp)
1223 {
1224 	struct pool_item_header *ph;
1225 	int r = 0;
1226 
1227 	TAILQ_FOREACH(ph, &pp->pr_emptypages, ph_pagelist)
1228 		r += pool_chk_page(pp, ph, pp->pr_itemsperpage);
1229 	TAILQ_FOREACH(ph, &pp->pr_fullpages, ph_pagelist)
1230 		r += pool_chk_page(pp, ph, 0);
1231 	TAILQ_FOREACH(ph, &pp->pr_partpages, ph_pagelist)
1232 		r += pool_chk_page(pp, ph, -1);
1233 
1234 	return (r);
1235 }
1236 #endif /* defined(POOL_DEBUG) || defined(DDB) */
1237 
1238 #ifdef DDB
1239 void
1240 pool_walk(struct pool *pp, int full,
1241     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))),
1242     void (*func)(void *, int, int (*)(const char *, ...)
1243 	    __attribute__((__format__(__kprintf__,1,2)))))
1244 {
1245 	struct pool_item_header *ph;
1246 	struct pool_item *pi;
1247 	caddr_t cp;
1248 	int n;
1249 
1250 	TAILQ_FOREACH(ph, &pp->pr_fullpages, ph_pagelist) {
1251 		cp = ph->ph_colored;
1252 		n = ph->ph_nmissing;
1253 
1254 		while (n--) {
1255 			func(cp, full, pr);
1256 			cp += pp->pr_size;
1257 		}
1258 	}
1259 
1260 	TAILQ_FOREACH(ph, &pp->pr_partpages, ph_pagelist) {
1261 		cp = ph->ph_colored;
1262 		n = ph->ph_nmissing;
1263 
1264 		do {
1265 			XSIMPLEQ_FOREACH(pi, &ph->ph_itemlist, pi_list) {
1266 				if (cp == (caddr_t)pi)
1267 					break;
1268 			}
1269 			if (cp != (caddr_t)pi) {
1270 				func(cp, full, pr);
1271 				n--;
1272 			}
1273 
1274 			cp += pp->pr_size;
1275 		} while (n > 0);
1276 	}
1277 }
1278 #endif
1279 
1280 /*
1281  * We have three different sysctls.
1282  * kern.pool.npools - the number of pools.
1283  * kern.pool.pool.<pool#> - the pool struct for the pool#.
1284  * kern.pool.name.<pool#> - the name for pool#.
1285  */
1286 int
1287 sysctl_dopool(int *name, u_int namelen, char *oldp, size_t *oldlenp)
1288 {
1289 	struct kinfo_pool pi;
1290 	struct pool *pp;
1291 	int rv = ENOENT;
1292 
1293 	switch (name[0]) {
1294 	case KERN_POOL_NPOOLS:
1295 		if (namelen != 1)
1296 			return (ENOTDIR);
1297 		return (sysctl_rdint(oldp, oldlenp, NULL, pool_count));
1298 
1299 	case KERN_POOL_NAME:
1300 	case KERN_POOL_POOL:
1301 		break;
1302 	default:
1303 		return (EOPNOTSUPP);
1304 	}
1305 
1306 	if (namelen != 2)
1307 		return (ENOTDIR);
1308 
1309 	rw_enter_read(&pool_lock);
1310 
1311 	SIMPLEQ_FOREACH(pp, &pool_head, pr_poollist) {
1312 		if (name[1] == pp->pr_serial)
1313 			break;
1314 	}
1315 
1316 	if (pp == NULL)
1317 		goto done;
1318 
1319 	switch (name[0]) {
1320 	case KERN_POOL_NAME:
1321 		rv = sysctl_rdstring(oldp, oldlenp, NULL, pp->pr_wchan);
1322 		break;
1323 	case KERN_POOL_POOL:
1324 		memset(&pi, 0, sizeof(pi));
1325 
1326 		if (pp->pr_ipl != -1)
1327 			mtx_enter(&pp->pr_mtx);
1328 		pi.pr_size = pp->pr_size;
1329 		pi.pr_pgsize = pp->pr_pgsize;
1330 		pi.pr_itemsperpage = pp->pr_itemsperpage;
1331 		pi.pr_npages = pp->pr_npages;
1332 		pi.pr_minpages = pp->pr_minpages;
1333 		pi.pr_maxpages = pp->pr_maxpages;
1334 		pi.pr_hardlimit = pp->pr_hardlimit;
1335 		pi.pr_nout = pp->pr_nout;
1336 		pi.pr_nitems = pp->pr_nitems;
1337 		pi.pr_nget = pp->pr_nget;
1338 		pi.pr_nput = pp->pr_nput;
1339 		pi.pr_nfail = pp->pr_nfail;
1340 		pi.pr_npagealloc = pp->pr_npagealloc;
1341 		pi.pr_npagefree = pp->pr_npagefree;
1342 		pi.pr_hiwat = pp->pr_hiwat;
1343 		pi.pr_nidle = pp->pr_nidle;
1344 		if (pp->pr_ipl != -1)
1345 			mtx_leave(&pp->pr_mtx);
1346 
1347 		rv = sysctl_rdstruct(oldp, oldlenp, NULL, &pi, sizeof(pi));
1348 		break;
1349 	}
1350 
1351 done:
1352 	rw_exit_read(&pool_lock);
1353 
1354 	return (rv);
1355 }
1356 
1357 void
1358 pool_gc_sched(void *null)
1359 {
1360 	task_add(systqmp, &pool_gc_task);
1361 }
1362 
1363 void
1364 pool_gc_pages(void *null)
1365 {
1366 	struct pool *pp;
1367 	struct pool_item_header *ph, *freeph;
1368 	int s;
1369 
1370 	rw_enter_read(&pool_lock);
1371 	s = splvm(); /* XXX go to splvm until all pools _setipl properly */
1372 	SIMPLEQ_FOREACH(pp, &pool_head, pr_poollist) {
1373 		if (pp->pr_nidle <= pp->pr_minpages || /* guess */
1374 		    !mtx_enter_try(&pp->pr_mtx)) /* try */
1375 			continue;
1376 
1377 		/* is it time to free a page? */
1378 		if (pp->pr_nidle > pp->pr_minpages &&
1379 		    (ph = TAILQ_FIRST(&pp->pr_emptypages)) != NULL &&
1380 		    (ticks - ph->ph_tick) > (hz * pool_wait_gc)) {
1381 			freeph = ph;
1382 			pool_p_remove(pp, freeph);
1383 		} else
1384 			freeph = NULL;
1385 
1386 		mtx_leave(&pp->pr_mtx);
1387 
1388 		if (freeph != NULL)
1389 			pool_p_free(pp, freeph);
1390 	}
1391 	splx(s);
1392 	rw_exit_read(&pool_lock);
1393 
1394 	timeout_add_sec(&pool_gc_tick, 1);
1395 }
1396 
1397 /*
1398  * Pool backend allocators.
1399  */
1400 
1401 void *
1402 pool_allocator_alloc(struct pool *pp, int flags, int *slowdown)
1403 {
1404 	void *v;
1405 
1406 	v = (*pp->pr_alloc->pa_alloc)(pp, flags, slowdown);
1407 
1408 #ifdef DIAGNOSTIC
1409 	if (v != NULL && POOL_INPGHDR(pp)) {
1410 		vaddr_t addr = (vaddr_t)v;
1411 		if ((addr & pp->pr_pgmask) != addr) {
1412 			panic("%s: %s page address %p isnt aligned to %u",
1413 			    __func__, pp->pr_wchan, v, pp->pr_pgsize);
1414 		}
1415 	}
1416 #endif
1417 
1418 	return (v);
1419 }
1420 
1421 void
1422 pool_allocator_free(struct pool *pp, void *v)
1423 {
1424 	struct pool_allocator *pa = pp->pr_alloc;
1425 
1426 	(*pa->pa_free)(pp, v);
1427 }
1428 
1429 void *
1430 pool_page_alloc(struct pool *pp, int flags, int *slowdown)
1431 {
1432 	struct kmem_dyn_mode kd = KMEM_DYN_INITIALIZER;
1433 
1434 	kd.kd_waitok = ISSET(flags, PR_WAITOK);
1435 	kd.kd_slowdown = slowdown;
1436 
1437 	return (km_alloc(pp->pr_pgsize, &kv_page, pp->pr_crange, &kd));
1438 }
1439 
1440 void
1441 pool_page_free(struct pool *pp, void *v)
1442 {
1443 	km_free(v, pp->pr_pgsize, &kv_page, pp->pr_crange);
1444 }
1445 
1446 void *
1447 pool_multi_alloc(struct pool *pp, int flags, int *slowdown)
1448 {
1449 	struct kmem_va_mode kv = kv_intrsafe;
1450 	struct kmem_dyn_mode kd = KMEM_DYN_INITIALIZER;
1451 	void *v;
1452 	int s;
1453 
1454 	if (POOL_INPGHDR(pp))
1455 		kv.kv_align = pp->pr_pgsize;
1456 
1457 	kd.kd_waitok = ISSET(flags, PR_WAITOK);
1458 	kd.kd_slowdown = slowdown;
1459 
1460 	s = splvm();
1461 	v = km_alloc(pp->pr_pgsize, &kv, pp->pr_crange, &kd);
1462 	splx(s);
1463 
1464 	return (v);
1465 }
1466 
1467 void
1468 pool_multi_free(struct pool *pp, void *v)
1469 {
1470 	struct kmem_va_mode kv = kv_intrsafe;
1471 	int s;
1472 
1473 	if (POOL_INPGHDR(pp))
1474 		kv.kv_align = pp->pr_pgsize;
1475 
1476 	s = splvm();
1477 	km_free(v, pp->pr_pgsize, &kv, pp->pr_crange);
1478 	splx(s);
1479 }
1480 
1481 void *
1482 pool_multi_alloc_ni(struct pool *pp, int flags, int *slowdown)
1483 {
1484 	struct kmem_va_mode kv = kv_any;
1485 	struct kmem_dyn_mode kd = KMEM_DYN_INITIALIZER;
1486 	void *v;
1487 
1488 	if (POOL_INPGHDR(pp))
1489 		kv.kv_align = pp->pr_pgsize;
1490 
1491 	kd.kd_waitok = ISSET(flags, PR_WAITOK);
1492 	kd.kd_slowdown = slowdown;
1493 
1494 	KERNEL_LOCK();
1495 	v = km_alloc(pp->pr_pgsize, &kv, pp->pr_crange, &kd);
1496 	KERNEL_UNLOCK();
1497 
1498 	return (v);
1499 }
1500 
1501 void
1502 pool_multi_free_ni(struct pool *pp, void *v)
1503 {
1504 	struct kmem_va_mode kv = kv_any;
1505 
1506 	if (POOL_INPGHDR(pp))
1507 		kv.kv_align = pp->pr_pgsize;
1508 
1509 	KERNEL_LOCK();
1510 	km_free(v, pp->pr_pgsize, &kv, pp->pr_crange);
1511 	KERNEL_UNLOCK();
1512 }
1513