2 * Copyright (c) Red Hat Inc.
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sub license,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the
12 * next paragraph) shall be included in all copies or substantial portions
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
23 * Authors: Dave Airlie <airlied@redhat.com>
24 * Jerome Glisse <jglisse@redhat.com>
25 * Pauli Nieminen <suokkos@gmail.com>
28 * Copyright (c) 2013 The FreeBSD Foundation
29 * All rights reserved.
31 * Portions of this software were developed by Konstantin Belousov
32 * <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
34 * $FreeBSD: head/sys/dev/drm2/ttm/ttm_page_alloc.c 247849 2013-03-05 16:15:34Z kib $
37 /* simple list based uncached page pool
38 * - Pool collects resently freed pages for reuse
39 * - Use page->lru to keep a free list
40 * - doesn't track currently in use pages
43 #include <sys/eventhandler.h>
46 #include <drm/ttm/ttm_bo_driver.h>
47 #include <drm/ttm/ttm_page_alloc.h>
53 #define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(vm_page_t))
54 #define SMALL_ALLOCATION 16
55 #define FREE_ALL_PAGES (~0U)
56 /* times are in msecs */
57 #define PAGE_FREE_INTERVAL 1000
60 * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
62 * @lock: Protects the shared pool from concurrnet access. Must be used with
63 * irqsave/irqrestore variants because pool allocator maybe called from
65 * @fill_lock: Prevent concurrent calls to fill.
66 * @list: Pool of free uc/wc pages for fast reuse.
67 * @gfp_flags: Flags to pass for alloc_page.
68 * @npages: Number of pages in pool.
70 struct ttm_page_pool {
75 int ttm_page_alloc_flags;
79 unsigned long nrefills;
83 * Limits for the pool. They are handled without locks because only place where
84 * they may change is in sysfs store. They won't have immediate effect anyway
85 * so forcing serialization to access them is pointless.
88 struct ttm_pool_opts {
97 * struct ttm_pool_manager - Holds memory pools for fst allocation
99 * Manager is read only object for pool code so it doesn't need locking.
101 * @free_interval: minimum number of jiffies between freeing pages from pool.
102 * @page_alloc_inited: reference counting for pool allocation.
103 * @work: Work that is used to shrink the pool. Work is only run when there is
104 * some pages to free.
105 * @small_allocation: Limit in number of pages what is small allocation.
107 * @pools: All pool objects in use.
109 struct ttm_pool_manager {
110 unsigned int kobj_ref;
111 eventhandler_tag lowmem_handler;
112 struct ttm_pool_opts options;
115 struct ttm_page_pool u_pools[NUM_POOLS];
117 struct ttm_page_pool u_wc_pool;
118 struct ttm_page_pool u_uc_pool;
119 struct ttm_page_pool u_wc_pool_dma32;
120 struct ttm_page_pool u_uc_pool_dma32;
125 #define pools _u.u_pools
126 #define wc_pool _u._ut.u_wc_pool
127 #define uc_pool _u._ut.u_uc_pool
128 #define wc_pool_dma32 _u._ut.u_wc_pool_dma32
129 #define uc_pool_dma32 _u._ut.u_uc_pool_dma32
132 ttm_vm_page_free(vm_page_t m)
135 KASSERT(m->object == NULL, ("ttm page %p is owned", m));
136 KASSERT(m->wire_count == 1, ("ttm lost wire %p", m));
137 KASSERT((m->flags & PG_FICTITIOUS) != 0, ("ttm lost fictitious %p", m));
139 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("ttm got unmanaged %p", m));
140 m->oflags |= VPO_UNMANAGED;
142 m->flags &= ~PG_FICTITIOUS;
143 vm_page_busy_wait(m, FALSE, "ttmvpf");
145 vm_page_free_contig(m, PAGE_SIZE);
147 vm_page_unwire(m, 0);
153 ttm_caching_state_to_vm(enum ttm_caching_state cstate)
158 return (VM_MEMATTR_UNCACHEABLE);
160 return (VM_MEMATTR_WRITE_COMBINING);
162 return (VM_MEMATTR_WRITE_BACK);
164 panic("caching state %d\n", cstate);
167 static void ttm_pool_kobj_release(struct ttm_pool_manager *m)
175 static ssize_t ttm_pool_store(struct ttm_pool_manager *m,
176 struct attribute *attr, const char *buffer, size_t size)
180 chars = sscanf(buffer, "%u", &val);
184 /* Convert kb to number of pages */
185 val = val / (PAGE_SIZE >> 10);
187 if (attr == &ttm_page_pool_max)
188 m->options.max_size = val;
189 else if (attr == &ttm_page_pool_small)
190 m->options.small = val;
191 else if (attr == &ttm_page_pool_alloc_size) {
192 if (val > NUM_PAGES_TO_ALLOC*8) {
193 pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
194 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
195 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
197 } else if (val > NUM_PAGES_TO_ALLOC) {
198 pr_warn("Setting allocation size to larger than %lu is not recommended\n",
199 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
201 m->options.alloc_size = val;
207 static ssize_t ttm_pool_show(struct ttm_pool_manager *m,
208 struct attribute *attr, char *buffer)
212 if (attr == &ttm_page_pool_max)
213 val = m->options.max_size;
214 else if (attr == &ttm_page_pool_small)
215 val = m->options.small;
216 else if (attr == &ttm_page_pool_alloc_size)
217 val = m->options.alloc_size;
219 val = val * (PAGE_SIZE >> 10);
221 return snprintf(buffer, PAGE_SIZE, "%u\n", val);
225 static struct ttm_pool_manager *_manager;
227 static int set_pages_array_wb(vm_page_t *pages, int addrinarray)
232 for (i = 0; i < addrinarray; i++) {
235 unmap_page_from_agp(m);
237 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_BACK);
242 static int set_pages_array_wc(vm_page_t *pages, int addrinarray)
247 for (i = 0; i < addrinarray; i++) {
250 map_page_into_agp(pages[i]);
252 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_COMBINING);
257 static int set_pages_array_uc(vm_page_t *pages, int addrinarray)
262 for (i = 0; i < addrinarray; i++) {
265 map_page_into_agp(pages[i]);
267 pmap_page_set_memattr(m, VM_MEMATTR_UNCACHEABLE);
273 * Select the right pool or requested caching state and ttm flags. */
274 static struct ttm_page_pool *ttm_get_pool(int flags,
275 enum ttm_caching_state cstate)
279 if (cstate == tt_cached)
287 if (flags & TTM_PAGE_FLAG_DMA32)
290 return &_manager->pools[pool_index];
293 /* set memory back to wb and free the pages. */
294 static void ttm_pages_put(vm_page_t *pages, unsigned npages)
298 /* Our VM handles vm memattr automatically on the page free. */
299 if (set_pages_array_wb(pages, npages))
300 kprintf("[TTM] Failed to set %d pages to wb!\n", npages);
301 for (i = 0; i < npages; ++i)
302 ttm_vm_page_free(pages[i]);
305 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
306 unsigned freed_pages)
308 pool->npages -= freed_pages;
309 pool->nfrees += freed_pages;
313 * Free pages from pool.
315 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
316 * number of pages in one go.
318 * @pool: to free the pages from
319 * @free_all: If set to true will free all pages in pool
321 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
324 vm_page_t *pages_to_free;
325 unsigned freed_pages = 0,
326 npages_to_free = nr_free;
329 if (NUM_PAGES_TO_ALLOC < nr_free)
330 npages_to_free = NUM_PAGES_TO_ALLOC;
332 pages_to_free = kmalloc(npages_to_free * sizeof(vm_page_t),
333 M_TEMP, M_WAITOK | M_ZERO);
336 lockmgr(&pool->lock, LK_EXCLUSIVE);
338 TAILQ_FOREACH_REVERSE_MUTABLE(p, &pool->list, pglist, pageq, p1) {
339 if (freed_pages >= npages_to_free)
342 pages_to_free[freed_pages++] = p;
343 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
344 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
345 /* remove range of pages from the pool */
346 for (i = 0; i < freed_pages; i++)
347 TAILQ_REMOVE(&pool->list, pages_to_free[i], pageq);
349 ttm_pool_update_free_locked(pool, freed_pages);
351 * Because changing page caching is costly
352 * we unlock the pool to prevent stalling.
354 lockmgr(&pool->lock, LK_RELEASE);
356 ttm_pages_put(pages_to_free, freed_pages);
357 if (likely(nr_free != FREE_ALL_PAGES))
358 nr_free -= freed_pages;
360 if (NUM_PAGES_TO_ALLOC >= nr_free)
361 npages_to_free = nr_free;
363 npages_to_free = NUM_PAGES_TO_ALLOC;
367 /* free all so restart the processing */
371 /* Not allowed to fall through or break because
372 * following context is inside spinlock while we are
380 /* remove range of pages from the pool */
382 for (i = 0; i < freed_pages; i++)
383 TAILQ_REMOVE(&pool->list, pages_to_free[i], pageq);
385 ttm_pool_update_free_locked(pool, freed_pages);
386 nr_free -= freed_pages;
389 lockmgr(&pool->lock, LK_RELEASE);
392 ttm_pages_put(pages_to_free, freed_pages);
394 drm_free(pages_to_free, M_TEMP);
398 /* Get good estimation how many pages are free in pools */
399 static int ttm_pool_get_num_unused_pages(void)
403 for (i = 0; i < NUM_POOLS; ++i)
404 total += _manager->pools[i].npages;
410 * Callback for mm to request pool to reduce number of page held.
412 static int ttm_pool_mm_shrink(void *arg)
414 static unsigned int start_pool = 0;
416 unsigned pool_offset = atomic_fetchadd_int(&start_pool, 1);
417 struct ttm_page_pool *pool;
418 int shrink_pages = 100; /* XXXKIB */
420 pool_offset = pool_offset % NUM_POOLS;
421 /* select start pool in round robin fashion */
422 for (i = 0; i < NUM_POOLS; ++i) {
423 unsigned nr_free = shrink_pages;
424 if (shrink_pages == 0)
426 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
427 shrink_pages = ttm_page_pool_free(pool, nr_free);
429 /* return estimated number of unused pages in pool */
430 return ttm_pool_get_num_unused_pages();
433 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
436 manager->lowmem_handler = EVENTHANDLER_REGISTER(vm_lowmem,
437 ttm_pool_mm_shrink, manager, EVENTHANDLER_PRI_ANY);
440 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
443 EVENTHANDLER_DEREGISTER(vm_lowmem, manager->lowmem_handler);
446 static int ttm_set_pages_caching(vm_page_t *pages,
447 enum ttm_caching_state cstate, unsigned cpages)
450 /* Set page caching */
453 r = set_pages_array_uc(pages, cpages);
455 kprintf("[TTM] Failed to set %d pages to uc!\n", cpages);
458 r = set_pages_array_wc(pages, cpages);
460 kprintf("[TTM] Failed to set %d pages to wc!\n", cpages);
469 * Free pages the pages that failed to change the caching state. If there is
470 * any pages that have changed their caching state already put them to the
473 static void ttm_handle_caching_state_failure(struct pglist *pages,
474 int ttm_flags, enum ttm_caching_state cstate,
475 vm_page_t *failed_pages, unsigned cpages)
478 /* Failed pages have to be freed */
479 for (i = 0; i < cpages; ++i) {
480 TAILQ_REMOVE(pages, failed_pages[i], pageq);
481 ttm_vm_page_free(failed_pages[i]);
486 * Allocate new pages with correct caching.
488 * This function is reentrant if caller updates count depending on number of
489 * pages returned in pages array.
491 static int ttm_alloc_new_pages(struct pglist *pages, int ttm_alloc_flags,
492 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
494 vm_page_t *caching_array;
497 unsigned i, cpages, aflags;
498 unsigned max_cpages = min(count,
499 (unsigned)(PAGE_SIZE/sizeof(vm_page_t)));
501 aflags = VM_ALLOC_NORMAL |
502 ((ttm_alloc_flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ?
505 /* allocate array for page caching change */
506 caching_array = kmalloc(max_cpages * sizeof(vm_page_t), M_TEMP,
509 for (i = 0, cpages = 0; i < count; ++i) {
510 p = vm_page_alloc_contig(0,
511 (ttm_alloc_flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
512 VM_MAX_ADDRESS, PAGE_SIZE, 0,
513 1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
515 kprintf("[TTM] Unable to get page %u\n", i);
517 /* store already allocated pages in the pool after
518 * setting the caching state */
520 r = ttm_set_pages_caching(caching_array,
523 ttm_handle_caching_state_failure(pages,
525 caching_array, cpages);
531 p->oflags &= ~VPO_UNMANAGED;
533 p->flags |= PG_FICTITIOUS;
535 #ifdef CONFIG_HIGHMEM /* KIB: nop */
536 /* gfp flags of highmem page should never be dma32 so we
537 * we should be fine in such case
542 caching_array[cpages++] = p;
543 if (cpages == max_cpages) {
545 r = ttm_set_pages_caching(caching_array,
548 ttm_handle_caching_state_failure(pages,
550 caching_array, cpages);
557 TAILQ_INSERT_HEAD(pages, p, pageq);
561 r = ttm_set_pages_caching(caching_array, cstate, cpages);
563 ttm_handle_caching_state_failure(pages,
565 caching_array, cpages);
568 drm_free(caching_array, M_TEMP);
574 * Fill the given pool if there aren't enough pages and the requested number of
577 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
578 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
584 * Only allow one pool fill operation at a time.
585 * If pool doesn't have enough pages for the allocation new pages are
586 * allocated from outside of pool.
591 pool->fill_lock = true;
593 /* If allocation request is small and there are not enough
594 * pages in a pool we fill the pool up first. */
595 if (count < _manager->options.small
596 && count > pool->npages) {
597 struct pglist new_pages;
598 unsigned alloc_size = _manager->options.alloc_size;
601 * Can't change page caching if in irqsave context. We have to
602 * drop the pool->lock.
604 lockmgr(&pool->lock, LK_RELEASE);
606 TAILQ_INIT(&new_pages);
607 r = ttm_alloc_new_pages(&new_pages, pool->ttm_page_alloc_flags,
608 ttm_flags, cstate, alloc_size);
609 lockmgr(&pool->lock, LK_EXCLUSIVE);
612 TAILQ_CONCAT(&pool->list, &new_pages, pageq);
614 pool->npages += alloc_size;
616 kprintf("[TTM] Failed to fill pool (%p)\n", pool);
617 /* If we have any pages left put them to the pool. */
618 TAILQ_FOREACH(p, &pool->list, pageq) {
621 TAILQ_CONCAT(&pool->list, &new_pages, pageq);
622 pool->npages += cpages;
626 pool->fill_lock = false;
630 * Cut 'count' number of pages from the pool and put them on the return list.
632 * @return count of pages still required to fulfill the request.
634 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
635 struct pglist *pages,
637 enum ttm_caching_state cstate,
643 lockmgr(&pool->lock, LK_EXCLUSIVE);
644 ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count);
646 if (count >= pool->npages) {
647 /* take all pages from the pool */
648 TAILQ_CONCAT(pages, &pool->list, pageq);
649 count -= pool->npages;
653 for (i = 0; i < count; i++) {
654 p = TAILQ_FIRST(&pool->list);
655 TAILQ_REMOVE(&pool->list, p, pageq);
656 TAILQ_INSERT_TAIL(pages, p, pageq);
658 pool->npages -= count;
661 lockmgr(&pool->lock, LK_RELEASE);
665 /* Put all pages in pages list to correct pool to wait for reuse */
666 static void ttm_put_pages(vm_page_t *pages, unsigned npages, int flags,
667 enum ttm_caching_state cstate)
669 struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
673 /* No pool for this memory type so free the pages */
674 for (i = 0; i < npages; i++) {
676 ttm_vm_page_free(pages[i]);
683 lockmgr(&pool->lock, LK_EXCLUSIVE);
684 for (i = 0; i < npages; i++) {
686 TAILQ_INSERT_TAIL(&pool->list, pages[i], pageq);
691 /* Check that we don't go over the pool limit */
693 if (pool->npages > _manager->options.max_size) {
694 npages = pool->npages - _manager->options.max_size;
695 /* free at least NUM_PAGES_TO_ALLOC number of pages
696 * to reduce calls to set_memory_wb */
697 if (npages < NUM_PAGES_TO_ALLOC)
698 npages = NUM_PAGES_TO_ALLOC;
700 lockmgr(&pool->lock, LK_RELEASE);
702 ttm_page_pool_free(pool, npages);
706 * On success pages list will hold count number of correctly
709 static int ttm_get_pages(vm_page_t *pages, unsigned npages, int flags,
710 enum ttm_caching_state cstate)
712 struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
715 int gfp_flags, aflags;
719 aflags = VM_ALLOC_NORMAL |
720 ((flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ? VM_ALLOC_ZERO : 0);
722 /* No pool for cached pages */
724 for (r = 0; r < npages; ++r) {
725 p = vm_page_alloc_contig(0,
726 (flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
727 VM_MAX_ADDRESS, PAGE_SIZE,
728 0, 1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
730 kprintf("[TTM] Unable to allocate page\n");
734 p->oflags &= ~VPO_UNMANAGED;
736 p->flags |= PG_FICTITIOUS;
742 /* combine zero flag to pool flags */
743 gfp_flags = flags | pool->ttm_page_alloc_flags;
745 /* First we take pages from the pool */
747 npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages);
749 TAILQ_FOREACH(p, &plist, pageq) {
753 /* clear the pages coming from the pool if requested */
754 if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
755 TAILQ_FOREACH(p, &plist, pageq) {
756 pmap_zero_page(VM_PAGE_TO_PHYS(p));
760 /* If pool didn't have enough pages allocate new one. */
762 /* ttm_alloc_new_pages doesn't reference pool so we can run
763 * multiple requests in parallel.
766 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate,
768 TAILQ_FOREACH(p, &plist, pageq) {
772 /* If there is any pages in the list put them back to
774 kprintf("[TTM] Failed to allocate extra pages for large request\n");
775 ttm_put_pages(pages, count, flags, cstate);
783 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
786 lockinit(&pool->lock, "ttmpool", 0, LK_CANRECURSE);
787 pool->fill_lock = false;
788 TAILQ_INIT(&pool->list);
789 pool->npages = pool->nfrees = 0;
790 pool->ttm_page_alloc_flags = flags;
794 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
797 if (_manager != NULL)
798 kprintf("[TTM] manager != NULL\n");
799 kprintf("[TTM] Initializing pool allocator\n");
801 _manager = kmalloc(sizeof(*_manager), M_DRM, M_WAITOK | M_ZERO);
803 ttm_page_pool_init_locked(&_manager->wc_pool, 0, "wc");
804 ttm_page_pool_init_locked(&_manager->uc_pool, 0, "uc");
805 ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
806 TTM_PAGE_FLAG_DMA32, "wc dma");
807 ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
808 TTM_PAGE_FLAG_DMA32, "uc dma");
810 _manager->options.max_size = max_pages;
811 _manager->options.small = SMALL_ALLOCATION;
812 _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
814 refcount_init(&_manager->kobj_ref, 1);
815 ttm_pool_mm_shrink_init(_manager);
820 void ttm_page_alloc_fini(void)
824 kprintf("[TTM] Finalizing pool allocator\n");
825 ttm_pool_mm_shrink_fini(_manager);
827 for (i = 0; i < NUM_POOLS; ++i)
828 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
830 if (refcount_release(&_manager->kobj_ref))
831 ttm_pool_kobj_release(_manager);
835 int ttm_pool_populate(struct ttm_tt *ttm)
837 struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
841 if (ttm->state != tt_unpopulated)
844 for (i = 0; i < ttm->num_pages; ++i) {
845 ret = ttm_get_pages(&ttm->pages[i], 1,
849 ttm_pool_unpopulate(ttm);
853 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
855 if (unlikely(ret != 0)) {
856 ttm_pool_unpopulate(ttm);
861 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
862 ret = ttm_tt_swapin(ttm);
863 if (unlikely(ret != 0)) {
864 ttm_pool_unpopulate(ttm);
869 ttm->state = tt_unbound;
873 void ttm_pool_unpopulate(struct ttm_tt *ttm)
877 for (i = 0; i < ttm->num_pages; ++i) {
879 ttm_mem_global_free_page(ttm->glob->mem_glob,
881 ttm_put_pages(&ttm->pages[i], 1,
886 ttm->state = tt_unpopulated;
891 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
893 struct ttm_page_pool *p;
895 char *h[] = {"pool", "refills", "pages freed", "size"};
897 seq_printf(m, "No pool allocator running.\n");
900 seq_printf(m, "%6s %12s %13s %8s\n",
901 h[0], h[1], h[2], h[3]);
902 for (i = 0; i < NUM_POOLS; ++i) {
903 p = &_manager->pools[i];
905 seq_printf(m, "%6s %12ld %13ld %8d\n",
906 p->name, p->nrefills,
907 p->nfrees, p->npages);