/* $NetBSD: subr_pool.c,v 1.276 2021/02/24 05:36:02 mrg Exp $ */ /* * Copyright (c) 1997, 1999, 2000, 2002, 2007, 2008, 2010, 2014, 2015, 2018, * 2020 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Paul Kranenburg; by Jason R. Thorpe of the Numerical Aerospace * Simulation Facility, NASA Ames Research Center; by Andrew Doran, and by * Maxime Villard. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include __KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.276 2021/02/24 05:36:02 mrg Exp $"); #ifdef _KERNEL_OPT #include "opt_ddb.h" #include "opt_lockdebug.h" #include "opt_pool.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Pool resource management utility. * * Memory is allocated in pages which are split into pieces according to * the pool item size. Each page is kept on one of three lists in the * pool structure: `pr_emptypages', `pr_fullpages' and `pr_partpages', * for empty, full and partially-full pages respectively. The individual * pool items are on a linked list headed by `ph_itemlist' in each page * header. The memory for building the page list is either taken from * the allocated pages themselves (for small pool items) or taken from * an internal pool of page headers (`phpool'). */ /* List of all pools. Non static as needed by 'vmstat -m' */ TAILQ_HEAD(, pool) pool_head = TAILQ_HEAD_INITIALIZER(pool_head); /* Private pool for page header structures */ #define PHPOOL_MAX 8 static struct pool phpool[PHPOOL_MAX]; #define PHPOOL_FREELIST_NELEM(idx) \ (((idx) == 0) ? BITMAP_MIN_SIZE : BITMAP_SIZE * (1 << (idx))) #if !defined(KMSAN) && (defined(DIAGNOSTIC) || defined(KASAN)) #define POOL_REDZONE #endif #if defined(POOL_QUARANTINE) #define POOL_NOCACHE #endif #ifdef POOL_REDZONE # ifdef KASAN # define POOL_REDZONE_SIZE 8 # else # define POOL_REDZONE_SIZE 2 # endif static void pool_redzone_init(struct pool *, size_t); static void pool_redzone_fill(struct pool *, void *); static void pool_redzone_check(struct pool *, void *); static void pool_cache_redzone_check(pool_cache_t, void *); #else # define pool_redzone_init(pp, sz) __nothing # define pool_redzone_fill(pp, ptr) __nothing # define pool_redzone_check(pp, ptr) __nothing # define pool_cache_redzone_check(pc, ptr) __nothing #endif #ifdef KMSAN static inline void pool_get_kmsan(struct pool *, void *); static inline void pool_put_kmsan(struct pool *, void *); static inline void pool_cache_get_kmsan(pool_cache_t, void *); static inline void pool_cache_put_kmsan(pool_cache_t, void *); #else #define pool_get_kmsan(pp, ptr) __nothing #define pool_put_kmsan(pp, ptr) __nothing #define pool_cache_get_kmsan(pc, ptr) __nothing #define pool_cache_put_kmsan(pc, ptr) __nothing #endif #ifdef POOL_QUARANTINE static void pool_quarantine_init(struct pool *); static void pool_quarantine_flush(struct pool *); static bool pool_put_quarantine(struct pool *, void *, struct pool_pagelist *); #else #define pool_quarantine_init(a) __nothing #define pool_quarantine_flush(a) __nothing #define pool_put_quarantine(a, b, c) false #endif #ifdef POOL_NOCACHE static bool pool_cache_put_nocache(pool_cache_t, void *); #else #define pool_cache_put_nocache(a, b) false #endif #define NO_CTOR __FPTRCAST(int (*)(void *, void *, int), nullop) #define NO_DTOR __FPTRCAST(void (*)(void *, void *), nullop) #define pc_has_ctor(pc) ((pc)->pc_ctor != NO_CTOR) #define pc_has_dtor(pc) ((pc)->pc_dtor != NO_DTOR) /* * Pool backend allocators. * * Each pool has a backend allocator that handles allocation, deallocation, * and any additional draining that might be needed. * * We provide two standard allocators: * * pool_allocator_kmem - the default when no allocator is specified * * pool_allocator_nointr - used for pools that will not be accessed * in interrupt context. */ void *pool_page_alloc(struct pool *, int); void pool_page_free(struct pool *, void *); static void *pool_page_alloc_meta(struct pool *, int); static void pool_page_free_meta(struct pool *, void *); struct pool_allocator pool_allocator_kmem = { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 0 }; struct pool_allocator pool_allocator_nointr = { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 0 }; struct pool_allocator pool_allocator_meta = { .pa_alloc = pool_page_alloc_meta, .pa_free = pool_page_free_meta, .pa_pagesz = 0 }; #define POOL_ALLOCATOR_BIG_BASE 13 static struct pool_allocator pool_allocator_big[] = { { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 0), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 1), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 2), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 3), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 4), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 5), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 6), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 7), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 8), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 9), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 10), }, { .pa_alloc = pool_page_alloc, .pa_free = pool_page_free, .pa_pagesz = 1 << (POOL_ALLOCATOR_BIG_BASE + 11), } }; static int pool_bigidx(size_t); /* # of seconds to retain page after last use */ int pool_inactive_time = 10; /* Next candidate for drainage (see pool_drain()) */ static struct pool *drainpp; /* This lock protects both pool_head and drainpp. */ static kmutex_t pool_head_lock; static kcondvar_t pool_busy; /* This lock protects initialization of a potentially shared pool allocator */ static kmutex_t pool_allocator_lock; static unsigned int poolid_counter = 0; typedef uint32_t pool_item_bitmap_t; #define BITMAP_SIZE (CHAR_BIT * sizeof(pool_item_bitmap_t)) #define BITMAP_MASK (BITMAP_SIZE - 1) #define BITMAP_MIN_SIZE (CHAR_BIT * sizeof(((struct pool_item_header *)NULL)->ph_u2)) struct pool_item_header { /* Page headers */ LIST_ENTRY(pool_item_header) ph_pagelist; /* pool page list */ union { /* !PR_PHINPAGE */ struct { SPLAY_ENTRY(pool_item_header) phu_node; /* off-page page headers */ } phu_offpage; /* PR_PHINPAGE */ struct { unsigned int phu_poolid; } phu_onpage; } ph_u1; void * ph_page; /* this page's address */ uint32_t ph_time; /* last referenced */ uint16_t ph_nmissing; /* # of chunks in use */ uint16_t ph_off; /* start offset in page */ union { /* !PR_USEBMAP */ struct { LIST_HEAD(, pool_item) phu_itemlist; /* chunk list for this page */ } phu_normal; /* PR_USEBMAP */ struct { pool_item_bitmap_t phu_bitmap[1]; } phu_notouch; } ph_u2; }; #define ph_node ph_u1.phu_offpage.phu_node #define ph_poolid ph_u1.phu_onpage.phu_poolid #define ph_itemlist ph_u2.phu_normal.phu_itemlist #define ph_bitmap ph_u2.phu_notouch.phu_bitmap #define PHSIZE ALIGN(sizeof(struct pool_item_header)) CTASSERT(offsetof(struct pool_item_header, ph_u2) + BITMAP_MIN_SIZE / CHAR_BIT == sizeof(struct pool_item_header)); #if defined(DIAGNOSTIC) && !defined(KASAN) #define POOL_CHECK_MAGIC #endif struct pool_item { #ifdef POOL_CHECK_MAGIC u_int pi_magic; #endif #define PI_MAGIC 0xdeaddeadU /* Other entries use only this list entry */ LIST_ENTRY(pool_item) pi_list; }; #define POOL_NEEDS_CATCHUP(pp) \ ((pp)->pr_nitems < (pp)->pr_minitems || \ (pp)->pr_npages < (pp)->pr_minpages) #define POOL_OBJ_TO_PAGE(pp, v) \ (void *)((uintptr_t)v & pp->pr_alloc->pa_pagemask) /* * Pool cache management. * * Pool caches provide a way for constructed objects to be cached by the * pool subsystem. This can lead to performance improvements by avoiding * needless object construction/destruction; it is deferred until absolutely * necessary. * * Caches are grouped into cache groups. Each cache group references up * to PCG_NUMOBJECTS constructed objects. When a cache allocates an * object from the pool, it calls the object's constructor and places it * into a cache group. When a cache group frees an object back to the * pool, it first calls the object's destructor. This allows the object * to persist in constructed form while freed to the cache. * * The pool references each cache, so that when a pool is drained by the * pagedaemon, it can drain each individual cache as well. Each time a * cache is drained, the most idle cache group is freed to the pool in * its entirety. * * Pool caches are layed on top of pools. By layering them, we can avoid * the complexity of cache management for pools which would not benefit * from it. */ static struct pool pcg_normal_pool; static struct pool pcg_large_pool; static struct pool cache_pool; static struct pool cache_cpu_pool; static pcg_t *volatile pcg_large_cache __cacheline_aligned; static pcg_t *volatile pcg_normal_cache __cacheline_aligned; /* List of all caches. */ TAILQ_HEAD(,pool_cache) pool_cache_head = TAILQ_HEAD_INITIALIZER(pool_cache_head); int pool_cache_disable; /* global disable for caching */ static const pcg_t pcg_dummy; /* zero sized: always empty, yet always full */ static bool pool_cache_put_slow(pool_cache_t, pool_cache_cpu_t *, int, void *); static bool pool_cache_get_slow(pool_cache_t, pool_cache_cpu_t *, int, void **, paddr_t *, int); static void pool_cache_cpu_init1(struct cpu_info *, pool_cache_t); static int pool_cache_invalidate_groups(pool_cache_t, pcg_t *); static void pool_cache_invalidate_cpu(pool_cache_t, u_int); static void pool_cache_transfer(pool_cache_t); static int pool_pcg_get(pcg_t *volatile *, pcg_t **); static int pool_pcg_put(pcg_t *volatile *, pcg_t *); static pcg_t * pool_pcg_trunc(pcg_t *volatile *); static int pool_catchup(struct pool *); static void pool_prime_page(struct pool *, void *, struct pool_item_header *); static void pool_update_curpage(struct pool *); static int pool_grow(struct pool *, int); static void *pool_allocator_alloc(struct pool *, int); static void pool_allocator_free(struct pool *, void *); static void pool_print_pagelist(struct pool *, struct pool_pagelist *, void (*)(const char *, ...) __printflike(1, 2)); static void pool_print1(struct pool *, const char *, void (*)(const char *, ...) __printflike(1, 2)); static int pool_chk_page(struct pool *, const char *, struct pool_item_header *); /* -------------------------------------------------------------------------- */ static inline unsigned int pr_item_bitmap_index(const struct pool *pp, const struct pool_item_header *ph, const void *v) { const char *cp = v; unsigned int idx; KASSERT(pp->pr_roflags & PR_USEBMAP); idx = (cp - (char *)ph->ph_page - ph->ph_off) / pp->pr_size; if (__predict_false(idx >= pp->pr_itemsperpage)) { panic("%s: [%s] %u >= %u", __func__, pp->pr_wchan, idx, pp->pr_itemsperpage); } return idx; } static inline void pr_item_bitmap_put(const struct pool *pp, struct pool_item_header *ph, void *obj) { unsigned int idx = pr_item_bitmap_index(pp, ph, obj); pool_item_bitmap_t *bitmap = ph->ph_bitmap + (idx / BITMAP_SIZE); pool_item_bitmap_t mask = 1U << (idx & BITMAP_MASK); if (__predict_false((*bitmap & mask) != 0)) { panic("%s: [%s] %p already freed", __func__, pp->pr_wchan, obj); } *bitmap |= mask; } static inline void * pr_item_bitmap_get(const struct pool *pp, struct pool_item_header *ph) { pool_item_bitmap_t *bitmap = ph->ph_bitmap; unsigned int idx; int i; for (i = 0; ; i++) { int bit; KASSERT((i * BITMAP_SIZE) < pp->pr_itemsperpage); bit = ffs32(bitmap[i]); if (bit) { pool_item_bitmap_t mask; bit--; idx = (i * BITMAP_SIZE) + bit; mask = 1U << bit; KASSERT((bitmap[i] & mask) != 0); bitmap[i] &= ~mask; break; } } KASSERT(idx < pp->pr_itemsperpage); return (char *)ph->ph_page + ph->ph_off + idx * pp->pr_size; } static inline void pr_item_bitmap_init(const struct pool *pp, struct pool_item_header *ph) { pool_item_bitmap_t *bitmap = ph->ph_bitmap; const int n = howmany(pp->pr_itemsperpage, BITMAP_SIZE); int i; for (i = 0; i < n; i++) { bitmap[i] = (pool_item_bitmap_t)-1; } } /* -------------------------------------------------------------------------- */ static inline void pr_item_linkedlist_put(const struct pool *pp, struct pool_item_header *ph, void *obj) { struct pool_item *pi = obj; #ifdef POOL_CHECK_MAGIC pi->pi_magic = PI_MAGIC; #endif if (pp->pr_redzone) { /* * Mark the pool_item as valid. The rest is already * invalid. */ kasan_mark(pi, sizeof(*pi), sizeof(*pi), 0); } LIST_INSERT_HEAD(&ph->ph_itemlist, pi, pi_list); } static inline void * pr_item_linkedlist_get(struct pool *pp, struct pool_item_header *ph) { struct pool_item *pi; void *v; v = pi = LIST_FIRST(&ph->ph_itemlist); if (__predict_false(v == NULL)) { mutex_exit(&pp->pr_lock); panic("%s: [%s] page empty", __func__, pp->pr_wchan); } KASSERTMSG((pp->pr_nitems > 0), "%s: [%s] nitems %u inconsistent on itemlist", __func__, pp->pr_wchan, pp->pr_nitems); #ifdef POOL_CHECK_MAGIC KASSERTMSG((pi->pi_magic == PI_MAGIC), "%s: [%s] free list modified: " "magic=%x; page %p; item addr %p", __func__, pp->pr_wchan, pi->pi_magic, ph->ph_page, pi); #endif /* * Remove from item list. */ LIST_REMOVE(pi, pi_list); return v; } /* -------------------------------------------------------------------------- */ static inline void pr_phinpage_check(struct pool *pp, struct pool_item_header *ph, void *page, void *object) { if (__predict_false((void *)ph->ph_page != page)) { panic("%s: [%s] item %p not part of pool", __func__, pp->pr_wchan, object); } if (__predict_false((char *)object < (char *)page + ph->ph_off)) { panic("%s: [%s] item %p below item space", __func__, pp->pr_wchan, object); } if (__predict_false(ph->ph_poolid != pp->pr_poolid)) { panic("%s: [%s] item %p poolid %u != %u", __func__, pp->pr_wchan, object, ph->ph_poolid, pp->pr_poolid); } } static inline void pc_phinpage_check(pool_cache_t pc, void *object) { struct pool_item_header *ph; struct pool *pp; void *page; pp = &pc->pc_pool; page = POOL_OBJ_TO_PAGE(pp, object); ph = (struct pool_item_header *)page; pr_phinpage_check(pp, ph, page, object); } /* -------------------------------------------------------------------------- */ static inline int phtree_compare(struct pool_item_header *a, struct pool_item_header *b) { /* * We consider pool_item_header with smaller ph_page bigger. This * unnatural ordering is for the benefit of pr_find_pagehead. */ if (a->ph_page < b->ph_page) return 1; else if (a->ph_page > b->ph_page) return -1; else return 0; } SPLAY_PROTOTYPE(phtree, pool_item_header, ph_node, phtree_compare); SPLAY_GENERATE(phtree, pool_item_header, ph_node, phtree_compare); static inline struct pool_item_header * pr_find_pagehead_noalign(struct pool *pp, void *v) { struct pool_item_header *ph, tmp; tmp.ph_page = (void *)(uintptr_t)v; ph = SPLAY_FIND(phtree, &pp->pr_phtree, &tmp); if (ph == NULL) { ph = SPLAY_ROOT(&pp->pr_phtree); if (ph != NULL && phtree_compare(&tmp, ph) >= 0) { ph = SPLAY_NEXT(phtree, &pp->pr_phtree, ph); } KASSERT(ph == NULL || phtree_compare(&tmp, ph) < 0); } return ph; } /* * Return the pool page header based on item address. */ static inline struct pool_item_header * pr_find_pagehead(struct pool *pp, void *v) { struct pool_item_header *ph, tmp; if ((pp->pr_roflags & PR_NOALIGN) != 0) { ph = pr_find_pagehead_noalign(pp, v); } else { void *page = POOL_OBJ_TO_PAGE(pp, v); if ((pp->pr_roflags & PR_PHINPAGE) != 0) { ph = (struct pool_item_header *)page; pr_phinpage_check(pp, ph, page, v); } else { tmp.ph_page = page; ph = SPLAY_FIND(phtree, &pp->pr_phtree, &tmp); } } KASSERT(ph == NULL || ((pp->pr_roflags & PR_PHINPAGE) != 0) || ((char *)ph->ph_page <= (char *)v && (char *)v < (char *)ph->ph_page + pp->pr_alloc->pa_pagesz)); return ph; } static void pr_pagelist_free(struct pool *pp, struct pool_pagelist *pq) { struct pool_item_header *ph; while ((ph = LIST_FIRST(pq)) != NULL) { LIST_REMOVE(ph, ph_pagelist); pool_allocator_free(pp, ph->ph_page); if ((pp->pr_roflags & PR_PHINPAGE) == 0) pool_put(pp->pr_phpool, ph); } } /* * Remove a page from the pool. */ static inline void pr_rmpage(struct pool *pp, struct pool_item_header *ph, struct pool_pagelist *pq) { KASSERT(mutex_owned(&pp->pr_lock)); /* * If the page was idle, decrement the idle page count. */ if (ph->ph_nmissing == 0) { KASSERT(pp->pr_nidle != 0); KASSERTMSG((pp->pr_nitems >= pp->pr_itemsperpage), "%s: [%s] nitems=%u < itemsperpage=%u", __func__, pp->pr_wchan, pp->pr_nitems, pp->pr_itemsperpage); pp->pr_nidle--; } pp->pr_nitems -= pp->pr_itemsperpage; /* * Unlink the page from the pool and queue it for release. */ LIST_REMOVE(ph, ph_pagelist); if (pp->pr_roflags & PR_PHINPAGE) { if (__predict_false(ph->ph_poolid != pp->pr_poolid)) { panic("%s: [%s] ph %p poolid %u != %u", __func__, pp->pr_wchan, ph, ph->ph_poolid, pp->pr_poolid); } } else { SPLAY_REMOVE(phtree, &pp->pr_phtree, ph); } LIST_INSERT_HEAD(pq, ph, ph_pagelist); pp->pr_npages--; pp->pr_npagefree++; pool_update_curpage(pp); } /* * Initialize all the pools listed in the "pools" link set. */ void pool_subsystem_init(void) { size_t size; int idx; mutex_init(&pool_head_lock, MUTEX_DEFAULT, IPL_NONE); mutex_init(&pool_allocator_lock, MUTEX_DEFAULT, IPL_NONE); cv_init(&pool_busy, "poolbusy"); /* * Initialize private page header pool and cache magazine pool if we * haven't done so yet. */ for (idx = 0; idx < PHPOOL_MAX; idx++) { static char phpool_names[PHPOOL_MAX][6+1+6+1]; int nelem; size_t sz; nelem = PHPOOL_FREELIST_NELEM(idx); KASSERT(nelem != 0); snprintf(phpool_names[idx], sizeof(phpool_names[idx]), "phpool-%d", nelem); sz = offsetof(struct pool_item_header, ph_bitmap[howmany(nelem, BITMAP_SIZE)]); pool_init(&phpool[idx], sz, 0, 0, 0, phpool_names[idx], &pool_allocator_meta, IPL_VM); } size = sizeof(pcg_t) + (PCG_NOBJECTS_NORMAL - 1) * sizeof(pcgpair_t); pool_init(&pcg_normal_pool, size, coherency_unit, 0, 0, "pcgnormal", &pool_allocator_meta, IPL_VM); size = sizeof(pcg_t) + (PCG_NOBJECTS_LARGE - 1) * sizeof(pcgpair_t); pool_init(&pcg_large_pool, size, coherency_unit, 0, 0, "pcglarge", &pool_allocator_meta, IPL_VM); pool_init(&cache_pool, sizeof(struct pool_cache), coherency_unit, 0, 0, "pcache", &pool_allocator_meta, IPL_NONE); pool_init(&cache_cpu_pool, sizeof(pool_cache_cpu_t), coherency_unit, 0, 0, "pcachecpu", &pool_allocator_meta, IPL_NONE); } static inline bool pool_init_is_phinpage(const struct pool *pp) { size_t pagesize; if (pp->pr_roflags & PR_PHINPAGE) { return true; } if (pp->pr_roflags & (PR_NOTOUCH | PR_NOALIGN)) { return false; } pagesize = pp->pr_alloc->pa_pagesz; /* * Threshold: the item size is below 1/16 of a page size, and below * 8 times the page header size. The latter ensures we go off-page * if the page header would make us waste a rather big item. */ if (pp->pr_size < MIN(pagesize / 16, PHSIZE * 8)) { return true; } /* Put the header into the page if it doesn't waste any items. */ if (pagesize / pp->pr_size == (pagesize - PHSIZE) / pp->pr_size) { return true; } return false; } static inline bool pool_init_is_usebmap(const struct pool *pp) { size_t bmapsize; if (pp->pr_roflags & PR_NOTOUCH) { return true; } /* * If we're off-page, go with a bitmap. */ if (!(pp->pr_roflags & PR_PHINPAGE)) { return true; } /* * If we're on-page, and the page header can already contain a bitmap * big enough to cover all the items of the page, go with a bitmap. */ bmapsize = roundup(PHSIZE, pp->pr_align) - offsetof(struct pool_item_header, ph_bitmap[0]); KASSERT(bmapsize % sizeof(pool_item_bitmap_t) == 0); if (pp->pr_itemsperpage <= bmapsize * CHAR_BIT) { return true; } return false; } /* * Initialize the given pool resource structure. * * We export this routine to allow other kernel parts to declare * static pools that must be initialized before kmem(9) is available. */ void pool_init(struct pool *pp, size_t size, u_int align, u_int ioff, int flags, const char *wchan, struct pool_allocator *palloc, int ipl) { struct pool *pp1; size_t prsize; int itemspace, slack; /* XXX ioff will be removed. */ KASSERT(ioff == 0); #ifdef DEBUG if (__predict_true(!cold)) mutex_enter(&pool_head_lock); /* * Check that the pool hasn't already been initialised and * added to the list of all pools. */ TAILQ_FOREACH(pp1, &pool_head, pr_poollist) { if (pp == pp1) panic("%s: [%s] already initialised", __func__, wchan); } if (__predict_true(!cold)) mutex_exit(&pool_head_lock); #endif if (palloc == NULL) palloc = &pool_allocator_kmem; if (!cold) mutex_enter(&pool_allocator_lock); if (palloc->pa_refcnt++ == 0) { if (palloc->pa_pagesz == 0) palloc->pa_pagesz = PAGE_SIZE; TAILQ_INIT(&palloc->pa_list); mutex_init(&palloc->pa_lock, MUTEX_DEFAULT, IPL_VM); palloc->pa_pagemask = ~(palloc->pa_pagesz - 1); palloc->pa_pageshift = ffs(palloc->pa_pagesz) - 1; } if (!cold) mutex_exit(&pool_allocator_lock); if (align == 0) align = ALIGN(1); prsize = size; if ((flags & PR_NOTOUCH) == 0 && prsize < sizeof(struct pool_item)) prsize = sizeof(struct pool_item); prsize = roundup(prsize, align); KASSERTMSG((prsize <= palloc->pa_pagesz), "%s: [%s] pool item size (%zu) larger than page size (%u)", __func__, wchan, prsize, palloc->pa_pagesz); /* * Initialize the pool structure. */ LIST_INIT(&pp->pr_emptypages); LIST_INIT(&pp->pr_fullpages); LIST_INIT(&pp->pr_partpages); pp->pr_cache = NULL; pp->pr_curpage = NULL; pp->pr_npages = 0; pp->pr_minitems = 0; pp->pr_minpages = 0; pp->pr_maxpages = UINT_MAX; pp->pr_roflags = flags; pp->pr_flags = 0; pp->pr_size = prsize; pp->pr_reqsize = size; pp->pr_align = align; pp->pr_wchan = wchan; pp->pr_alloc = palloc; pp->pr_poolid = atomic_inc_uint_nv(&poolid_counter); pp->pr_nitems = 0; pp->pr_nout = 0; pp->pr_hardlimit = UINT_MAX; pp->pr_hardlimit_warning = NULL; pp->pr_hardlimit_ratecap.tv_sec = 0; pp->pr_hardlimit_ratecap.tv_usec = 0; pp->pr_hardlimit_warning_last.tv_sec = 0; pp->pr_hardlimit_warning_last.tv_usec = 0; pp->pr_drain_hook = NULL; pp->pr_drain_hook_arg = NULL; pp->pr_freecheck = NULL; pp->pr_redzone = false; pool_redzone_init(pp, size); pool_quarantine_init(pp); /* * Decide whether to put the page header off-page to avoid wasting too * large a part of the page or too big an item. Off-page page headers * go on a hash table, so we can match a returned item with its header * based on the page address. */ if (pool_init_is_phinpage(pp)) { /* Use the beginning of the page for the page header */ itemspace = palloc->pa_pagesz - roundup(PHSIZE, align); pp->pr_itemoffset = roundup(PHSIZE, align); pp->pr_roflags |= PR_PHINPAGE; } else { /* The page header will be taken from our page header pool */ itemspace = palloc->pa_pagesz; pp->pr_itemoffset = 0; SPLAY_INIT(&pp->pr_phtree); } pp->pr_itemsperpage = itemspace / pp->pr_size; KASSERT(pp->pr_itemsperpage != 0); /* * Decide whether to use a bitmap or a linked list to manage freed * items. */ if (pool_init_is_usebmap(pp)) { pp->pr_roflags |= PR_USEBMAP; } /* * If we're off-page, then we're using a bitmap; choose the appropriate * pool to allocate page headers, whose size varies depending on the * bitmap. If we're on-page, nothing to do. */ if (!(pp->pr_roflags & PR_PHINPAGE)) { int idx; KASSERT(pp->pr_roflags & PR_USEBMAP); for (idx = 0; pp->pr_itemsperpage > PHPOOL_FREELIST_NELEM(idx); idx++) { /* nothing */ } if (idx >= PHPOOL_MAX) { /* * if you see this panic, consider to tweak * PHPOOL_MAX and PHPOOL_FREELIST_NELEM. */ panic("%s: [%s] too large itemsperpage(%d) for " "PR_USEBMAP", __func__, pp->pr_wchan, pp->pr_itemsperpage); } pp->pr_phpool = &phpool[idx]; } else { pp->pr_phpool = NULL; } /* * Use the slack between the chunks and the page header * for "cache coloring". */ slack = itemspace - pp->pr_itemsperpage * pp->pr_size; pp->pr_maxcolor = rounddown(slack, align); pp->pr_curcolor = 0; pp->pr_nget = 0; pp->pr_nfail = 0; pp->pr_nput = 0; pp->pr_npagealloc = 0; pp->pr_npagefree = 0; pp->pr_hiwat = 0; pp->pr_nidle = 0; pp->pr_refcnt = 0; mutex_init(&pp->pr_lock, MUTEX_DEFAULT, ipl); cv_init(&pp->pr_cv, wchan); pp->pr_ipl = ipl; /* Insert into the list of all pools. */ if (!cold) mutex_enter(&pool_head_lock); TAILQ_FOREACH(pp1, &pool_head, pr_poollist) { if (strcmp(pp1->pr_wchan, pp->pr_wchan) > 0) break; } if (pp1 == NULL) TAILQ_INSERT_TAIL(&pool_head, pp, pr_poollist); else TAILQ_INSERT_BEFORE(pp1, pp, pr_poollist); if (!cold) mutex_exit(&pool_head_lock); /* Insert this into the list of pools using this allocator. */ if (!cold) mutex_enter(&palloc->pa_lock); TAILQ_INSERT_TAIL(&palloc->pa_list, pp, pr_alloc_list); if (!cold) mutex_exit(&palloc->pa_lock); } /* * De-commision a pool resource. */ void pool_destroy(struct pool *pp) { struct pool_pagelist pq; struct pool_item_header *ph; pool_quarantine_flush(pp); /* Remove from global pool list */ mutex_enter(&pool_head_lock); while (pp->pr_refcnt != 0) cv_wait(&pool_busy, &pool_head_lock); TAILQ_REMOVE(&pool_head, pp, pr_poollist); if (drainpp == pp) drainpp = NULL; mutex_exit(&pool_head_lock); /* Remove this pool from its allocator's list of pools. */ mutex_enter(&pp->pr_alloc->pa_lock); TAILQ_REMOVE(&pp->pr_alloc->pa_list, pp, pr_alloc_list); mutex_exit(&pp->pr_alloc->pa_lock); mutex_enter(&pool_allocator_lock); if (--pp->pr_alloc->pa_refcnt == 0) mutex_destroy(&pp->pr_alloc->pa_lock); mutex_exit(&pool_allocator_lock); mutex_enter(&pp->pr_lock); KASSERT(pp->pr_cache == NULL); KASSERTMSG((pp->pr_nout == 0), "%s: [%s] pool busy: still out: %u", __func__, pp->pr_wchan, pp->pr_nout); KASSERT(LIST_EMPTY(&pp->pr_fullpages)); KASSERT(LIST_EMPTY(&pp->pr_partpages)); /* Remove all pages */ LIST_INIT(&pq); while ((ph = LIST_FIRST(&pp->pr_emptypages)) != NULL) pr_rmpage(pp, ph, &pq); mutex_exit(&pp->pr_lock); pr_pagelist_free(pp, &pq); cv_destroy(&pp->pr_cv); mutex_destroy(&pp->pr_lock); } void pool_set_drain_hook(struct pool *pp, void (*fn)(void *, int), void *arg) { /* XXX no locking -- must be used just after pool_init() */ KASSERTMSG((pp->pr_drain_hook == NULL), "%s: [%s] already set", __func__, pp->pr_wchan); pp->pr_drain_hook = fn; pp->pr_drain_hook_arg = arg; } static struct pool_item_header * pool_alloc_item_header(struct pool *pp, void *storage, int flags) { struct pool_item_header *ph; if ((pp->pr_roflags & PR_PHINPAGE) != 0) ph = storage; else ph = pool_get(pp->pr_phpool, flags); return ph; } /* * Grab an item from the pool. */ void * pool_get(struct pool *pp, int flags) { struct pool_item_header *ph; void *v; KASSERT(!(flags & PR_NOWAIT) != !(flags & PR_WAITOK)); KASSERTMSG((pp->pr_itemsperpage != 0), "%s: [%s] pr_itemsperpage is zero, " "pool not initialized?", __func__, pp->pr_wchan); KASSERTMSG((!(cpu_intr_p() || cpu_softintr_p()) || pp->pr_ipl != IPL_NONE || cold || panicstr != NULL), "%s: [%s] is IPL_NONE, but called from interrupt context", __func__, pp->pr_wchan); if (flags & PR_WAITOK) { ASSERT_SLEEPABLE(); } if (flags & PR_NOWAIT) { if (fault_inject()) return NULL; } mutex_enter(&pp->pr_lock); startover: /* * Check to see if we've reached the hard limit. If we have, * and we can wait, then wait until an item has been returned to * the pool. */ KASSERTMSG((pp->pr_nout <= pp->pr_hardlimit), "%s: %s: crossed hard limit", __func__, pp->pr_wchan); if (__predict_false(pp->pr_nout == pp->pr_hardlimit)) { if (pp->pr_drain_hook != NULL) { /* * Since the drain hook is going to free things * back to the pool, unlock, call the hook, re-lock, * and check the hardlimit condition again. */ mutex_exit(&pp->pr_lock); (*pp->pr_drain_hook)(pp->pr_drain_hook_arg, flags); mutex_enter(&pp->pr_lock); if (pp->pr_nout < pp->pr_hardlimit) goto startover; } if ((flags & PR_WAITOK) && !(flags & PR_LIMITFAIL)) { /* * XXX: A warning isn't logged in this case. Should * it be? */ pp->pr_flags |= PR_WANTED; do { cv_wait(&pp->pr_cv, &pp->pr_lock); } while (pp->pr_flags & PR_WANTED); goto startover; } /* * Log a message that the hard limit has been hit. */ if (pp->pr_hardlimit_warning != NULL && ratecheck(&pp->pr_hardlimit_warning_last, &pp->pr_hardlimit_ratecap)) log(LOG_ERR, "%s\n", pp->pr_hardlimit_warning); pp->pr_nfail++; mutex_exit(&pp->pr_lock); KASSERT((flags & (PR_NOWAIT|PR_LIMITFAIL)) != 0); return NULL; } /* * The convention we use is that if `curpage' is not NULL, then * it points at a non-empty bucket. In particular, `curpage' * never points at a page header which has PR_PHINPAGE set and * has no items in its bucket. */ if ((ph = pp->pr_curpage) == NULL) { int error; KASSERTMSG((pp->pr_nitems == 0), "%s: [%s] curpage NULL, inconsistent nitems %u", __func__, pp->pr_wchan, pp->pr_nitems); /* * Call the back-end page allocator for more memory. * Release the pool lock, as the back-end page allocator * may block. */ error = pool_grow(pp, flags); if (error != 0) { /* * pool_grow aborts when another thread * is allocating a new page. Retry if it * waited for it. */ if (error == ERESTART) goto startover; /* * We were unable to allocate a page or item * header, but we released the lock during * allocation, so perhaps items were freed * back to the pool. Check for this case. */ if (pp->pr_curpage != NULL) goto startover; pp->pr_nfail++; mutex_exit(&pp->pr_lock); KASSERT((flags & (PR_NOWAIT|PR_LIMITFAIL)) != 0); return NULL; } /* Start the allocation process over. */ goto startover; } if (pp->pr_roflags & PR_USEBMAP) { KASSERTMSG((ph->ph_nmissing < pp->pr_itemsperpage), "%s: [%s] pool page empty", __func__, pp->pr_wchan); v = pr_item_bitmap_get(pp, ph); } else { v = pr_item_linkedlist_get(pp, ph); } pp->pr_nitems--; pp->pr_nout++; if (ph->ph_nmissing == 0) { KASSERT(pp->pr_nidle > 0); pp->pr_nidle--; /* * This page was previously empty. Move it to the list of * partially-full pages. This page is already curpage. */ LIST_REMOVE(ph, ph_pagelist); LIST_INSERT_HEAD(&pp->pr_partpages, ph, ph_pagelist); } ph->ph_nmissing++; if (ph->ph_nmissing == pp->pr_itemsperpage) { KASSERTMSG(((pp->pr_roflags & PR_USEBMAP) || LIST_EMPTY(&ph->ph_itemlist)), "%s: [%s] nmissing (%u) inconsistent", __func__, pp->pr_wchan, ph->ph_nmissing); /* * This page is now full. Move it to the full list * and select a new current page. */ LIST_REMOVE(ph, ph_pagelist); LIST_INSERT_HEAD(&pp->pr_fullpages, ph, ph_pagelist); pool_update_curpage(pp); } pp->pr_nget++; /* * If we have a low water mark and we are now below that low * water mark, add more items to the pool. */ if (POOL_NEEDS_CATCHUP(pp) && pool_catchup(pp) != 0) { /* * XXX: Should we log a warning? Should we set up a timeout * to try again in a second or so? The latter could break * a caller's assumptions about interrupt protection, etc. */ } mutex_exit(&pp->pr_lock); KASSERT((((vaddr_t)v) & (pp->pr_align - 1)) == 0); FREECHECK_OUT(&pp->pr_freecheck, v); pool_redzone_fill(pp, v); pool_get_kmsan(pp, v); if (flags & PR_ZERO) memset(v, 0, pp->pr_reqsize); return v; } /* * Internal version of pool_put(). Pool is already locked/entered. */ static void pool_do_put(struct pool *pp, void *v, struct pool_pagelist *pq) { struct pool_item_header *ph; KASSERT(mutex_owned(&pp->pr_lock)); pool_redzone_check(pp, v); pool_put_kmsan(pp, v); FREECHECK_IN(&pp->pr_freecheck, v); LOCKDEBUG_MEM_CHECK(v, pp->pr_size); KASSERTMSG((pp->pr_nout > 0), "%s: [%s] putting with none out", __func__, pp->pr_wchan); if (__predict_false((ph = pr_find_pagehead(pp, v)) == NULL)) { panic("%s: [%s] page header missing", __func__, pp->pr_wchan); } /* * Return to item list. */ if (pp->pr_roflags & PR_USEBMAP) { pr_item_bitmap_put(pp, ph, v); } else { pr_item_linkedlist_put(pp, ph, v); } KDASSERT(ph->ph_nmissing != 0); ph->ph_nmissing--; pp->pr_nput++; pp->pr_nitems++; pp->pr_nout--; /* Cancel "pool empty" condition if it exists */ if (pp->pr_curpage == NULL) pp->pr_curpage = ph; if (pp->pr_flags & PR_WANTED) { pp->pr_flags &= ~PR_WANTED; cv_broadcast(&pp->pr_cv); } /* * If this page is now empty, do one of two things: * * (1) If we have more pages than the page high water mark, * free the page back to the system. ONLY CONSIDER * FREEING BACK A PAGE IF WE HAVE MORE THAN OUR MINIMUM PAGE * CLAIM. * * (2) Otherwise, move the page to the empty page list. * * Either way, select a new current page (so we use a partially-full * page if one is available). */ if (ph->ph_nmissing == 0) { pp->pr_nidle++; if (pp->pr_nitems - pp->pr_itemsperpage >= pp->pr_minitems && pp->pr_npages > pp->pr_minpages && pp->pr_npages > pp->pr_maxpages) { pr_rmpage(pp, ph, pq); } else { LIST_REMOVE(ph, ph_pagelist); LIST_INSERT_HEAD(&pp->pr_emptypages, ph, ph_pagelist); /* * Update the timestamp on the page. A page must * be idle for some period of time before it can * be reclaimed by the pagedaemon. This minimizes * ping-pong'ing for memory. * * note for 64-bit time_t: truncating to 32-bit is not * a problem for our usage. */ ph->ph_time = time_uptime; } pool_update_curpage(pp); } /* * If the page was previously completely full, move it to the * partially-full list and make it the current page. The next * allocation will get the item from this page, instead of * further fragmenting the pool. */ else if (ph->ph_nmissing == (pp->pr_itemsperpage - 1)) { LIST_REMOVE(ph, ph_pagelist); LIST_INSERT_HEAD(&pp->pr_partpages, ph, ph_pagelist); pp->pr_curpage = ph; } } void pool_put(struct pool *pp, void *v) { struct pool_pagelist pq; LIST_INIT(&pq); mutex_enter(&pp->pr_lock); if (!pool_put_quarantine(pp, v, &pq)) { pool_do_put(pp, v, &pq); } mutex_exit(&pp->pr_lock); pr_pagelist_free(pp, &pq); } /* * pool_grow: grow a pool by a page. * * => called with pool locked. * => unlock and relock the pool. * => return with pool locked. */ static int pool_grow(struct pool *pp, int flags) { struct pool_item_header *ph; char *storage; /* * If there's a pool_grow in progress, wait for it to complete * and try again from the top. */ if (pp->pr_flags & PR_GROWING) { if (flags & PR_WAITOK) { do { cv_wait(&pp->pr_cv, &pp->pr_lock); } while (pp->pr_flags & PR_GROWING); return ERESTART; } else { if (pp->pr_flags & PR_GROWINGNOWAIT) { /* * This needs an unlock/relock dance so * that the other caller has a chance to * run and actually do the thing. Note * that this is effectively a busy-wait. */ mutex_exit(&pp->pr_lock); mutex_enter(&pp->pr_lock); return ERESTART; } return EWOULDBLOCK; } } pp->pr_flags |= PR_GROWING; if (flags & PR_WAITOK) mutex_exit(&pp->pr_lock); else pp->pr_flags |= PR_GROWINGNOWAIT; storage = pool_allocator_alloc(pp, flags); if (__predict_false(storage == NULL)) goto out; ph = pool_alloc_item_header(pp, storage, flags); if (__predict_false(ph == NULL)) { pool_allocator_free(pp, storage); goto out; } if (flags & PR_WAITOK) mutex_enter(&pp->pr_lock); pool_prime_page(pp, storage, ph); pp->pr_npagealloc++; KASSERT(pp->pr_flags & PR_GROWING); pp->pr_flags &= ~(PR_GROWING|PR_GROWINGNOWAIT); /* * If anyone was waiting for pool_grow, notify them that we * may have just done it. */ cv_broadcast(&pp->pr_cv); return 0; out: if (flags & PR_WAITOK) mutex_enter(&pp->pr_lock); KASSERT(pp->pr_flags & PR_GROWING); pp->pr_flags &= ~(PR_GROWING|PR_GROWINGNOWAIT); return ENOMEM; } void pool_prime(struct pool *pp, int n) { mutex_enter(&pp->pr_lock); pp->pr_minpages = roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage; if (pp->pr_maxpages <= pp->pr_minpages) pp->pr_maxpages = pp->pr_minpages + 1; /* XXX */ while (pp->pr_npages < pp->pr_minpages) (void) pool_grow(pp, PR_WAITOK); mutex_exit(&pp->pr_lock); } /* * Add a page worth of items to the pool. * * Note, we must be called with the pool descriptor LOCKED. */ static void pool_prime_page(struct pool *pp, void *storage, struct pool_item_header *ph) { const unsigned int align = pp->pr_align; struct pool_item *pi; void *cp = storage; int n; KASSERT(mutex_owned(&pp->pr_lock)); KASSERTMSG(((pp->pr_roflags & PR_NOALIGN) || (((uintptr_t)cp & (pp->pr_alloc->pa_pagesz - 1)) == 0)), "%s: [%s] unaligned page: %p", __func__, pp->pr_wchan, cp); /* * Insert page header. */ LIST_INSERT_HEAD(&pp->pr_emptypages, ph, ph_pagelist); LIST_INIT(&ph->ph_itemlist); ph->ph_page = storage; ph->ph_nmissing = 0; ph->ph_time = time_uptime; if (pp->pr_roflags & PR_PHINPAGE) ph->ph_poolid = pp->pr_poolid; else SPLAY_INSERT(phtree, &pp->pr_phtree, ph); pp->pr_nidle++; /* * The item space starts after the on-page header, if any. */ ph->ph_off = pp->pr_itemoffset; /* * Color this page. */ ph->ph_off += pp->pr_curcolor; cp = (char *)cp + ph->ph_off; if ((pp->pr_curcolor += align) > pp->pr_maxcolor) pp->pr_curcolor = 0; KASSERT((((vaddr_t)cp) & (align - 1)) == 0); /* * Insert remaining chunks on the bucket list. */ n = pp->pr_itemsperpage; pp->pr_nitems += n; if (pp->pr_roflags & PR_USEBMAP) { pr_item_bitmap_init(pp, ph); } else { while (n--) { pi = (struct pool_item *)cp; KASSERT((((vaddr_t)pi) & (align - 1)) == 0); /* Insert on page list */ LIST_INSERT_HEAD(&ph->ph_itemlist, pi, pi_list); #ifdef POOL_CHECK_MAGIC pi->pi_magic = PI_MAGIC; #endif cp = (char *)cp + pp->pr_size; KASSERT((((vaddr_t)cp) & (align - 1)) == 0); } } /* * If the pool was depleted, point at the new page. */ if (pp->pr_curpage == NULL) pp->pr_curpage = ph; if (++pp->pr_npages > pp->pr_hiwat) pp->pr_hiwat = pp->pr_npages; } /* * Used by pool_get() when nitems drops below the low water mark. This * is used to catch up pr_nitems with the low water mark. * * Note 1, we never wait for memory here, we let the caller decide what to do. * * Note 2, we must be called with the pool already locked, and we return * with it locked. */ static int pool_catchup(struct pool *pp) { int error = 0; while (POOL_NEEDS_CATCHUP(pp)) { error = pool_grow(pp, PR_NOWAIT); if (error) { if (error == ERESTART) continue; break; } } return error; } static void pool_update_curpage(struct pool *pp) { pp->pr_curpage = LIST_FIRST(&pp->pr_partpages); if (pp->pr_curpage == NULL) { pp->pr_curpage = LIST_FIRST(&pp->pr_emptypages); } KASSERT((pp->pr_curpage == NULL && pp->pr_nitems == 0) || (pp->pr_curpage != NULL && pp->pr_nitems > 0)); } void pool_setlowat(struct pool *pp, int n) { mutex_enter(&pp->pr_lock); pp->pr_minitems = n; /* Make sure we're caught up with the newly-set low water mark. */ if (POOL_NEEDS_CATCHUP(pp) && pool_catchup(pp) != 0) { /* * XXX: Should we log a warning? Should we set up a timeout * to try again in a second or so? The latter could break * a caller's assumptions about interrupt protection, etc. */ } mutex_exit(&pp->pr_lock); } void pool_sethiwat(struct pool *pp, int n) { mutex_enter(&pp->pr_lock); pp->pr_maxitems = n; mutex_exit(&pp->pr_lock); } void pool_sethardlimit(struct pool *pp, int n, const char *warnmess, int ratecap) { mutex_enter(&pp->pr_lock); pp->pr_hardlimit = n; pp->pr_hardlimit_warning = warnmess; pp->pr_hardlimit_ratecap.tv_sec = ratecap; pp->pr_hardlimit_warning_last.tv_sec = 0; pp->pr_hardlimit_warning_last.tv_usec = 0; pp->pr_maxpages = roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage; mutex_exit(&pp->pr_lock); } /* * Release all complete pages that have not been used recently. * * Must not be called from interrupt context. */ int pool_reclaim(struct pool *pp) { struct pool_item_header *ph, *phnext; struct pool_pagelist pq; uint32_t curtime; bool klock; int rv; KASSERT(!cpu_intr_p() && !cpu_softintr_p()); if (pp->pr_drain_hook != NULL) { /* * The drain hook must be called with the pool unlocked. */ (*pp->pr_drain_hook)(pp->pr_drain_hook_arg, PR_NOWAIT); } /* * XXXSMP Because we do not want to cause non-MPSAFE code * to block. */ if (pp->pr_ipl == IPL_SOFTNET || pp->pr_ipl == IPL_SOFTCLOCK || pp->pr_ipl == IPL_SOFTSERIAL) { KERNEL_LOCK(1, NULL); klock = true; } else klock = false; /* Reclaim items from the pool's cache (if any). */ if (pp->pr_cache != NULL) pool_cache_invalidate(pp->pr_cache); if (mutex_tryenter(&pp->pr_lock) == 0) { if (klock) { KERNEL_UNLOCK_ONE(NULL); } return 0; } LIST_INIT(&pq); curtime = time_uptime; for (ph = LIST_FIRST(&pp->pr_emptypages); ph != NULL; ph = phnext) { phnext = LIST_NEXT(ph, ph_pagelist); /* Check our minimum page claim */ if (pp->pr_npages <= pp->pr_minpages) break; KASSERT(ph->ph_nmissing == 0); if (curtime - ph->ph_time < pool_inactive_time) continue; /* * If freeing this page would put us below the minimum free items * or the minimum pages, stop now. */ if (pp->pr_nitems - pp->pr_itemsperpage < pp->pr_minitems || pp->pr_npages - 1 < pp->pr_minpages) break; pr_rmpage(pp, ph, &pq); } mutex_exit(&pp->pr_lock); if (LIST_EMPTY(&pq)) rv = 0; else { pr_pagelist_free(pp, &pq); rv = 1; } if (klock) { KERNEL_UNLOCK_ONE(NULL); } return rv; } /* * Drain pools, one at a time. The drained pool is returned within ppp. * * Note, must never be called from interrupt context. */ bool pool_drain(struct pool **ppp) { bool reclaimed; struct pool *pp; KASSERT(!TAILQ_EMPTY(&pool_head)); pp = NULL; /* Find next pool to drain, and add a reference. */ mutex_enter(&pool_head_lock); do { if (drainpp == NULL) { drainpp = TAILQ_FIRST(&pool_head); } if (drainpp != NULL) { pp = drainpp; drainpp = TAILQ_NEXT(pp, pr_poollist); } /* * Skip completely idle pools. We depend on at least * one pool in the system being active. */ } while (pp == NULL || pp->pr_npages == 0); pp->pr_refcnt++; mutex_exit(&pool_head_lock); /* Drain the cache (if any) and pool.. */ reclaimed = pool_reclaim(pp); /* Finally, unlock the pool. */ mutex_enter(&pool_head_lock); pp->pr_refcnt--; cv_broadcast(&pool_busy); mutex_exit(&pool_head_lock); if (ppp != NULL) *ppp = pp; return reclaimed; } /* * Calculate the total number of pages consumed by pools. */ int pool_totalpages(void) { mutex_enter(&pool_head_lock); int pages = pool_totalpages_locked(); mutex_exit(&pool_head_lock); return pages; } int pool_totalpages_locked(void) { struct pool *pp; uint64_t total = 0; TAILQ_FOREACH(pp, &pool_head, pr_poollist) { uint64_t bytes = pp->pr_npages * pp->pr_alloc->pa_pagesz; if ((pp->pr_roflags & PR_RECURSIVE) != 0) bytes -= (pp->pr_nout * pp->pr_size); total += bytes; } return atop(total); } /* * Diagnostic helpers. */ void pool_printall(const char *modif, void (*pr)(const char *, ...)) { struct pool *pp; TAILQ_FOREACH(pp, &pool_head, pr_poollist) { pool_printit(pp, modif, pr); } } void pool_printit(struct pool *pp, const char *modif, void (*pr)(const char *, ...)) { if (pp == NULL) { (*pr)("Must specify a pool to print.\n"); return; } pool_print1(pp, modif, pr); } static void pool_print_pagelist(struct pool *pp, struct pool_pagelist *pl, void (*pr)(const char *, ...)) { struct pool_item_header *ph; LIST_FOREACH(ph, pl, ph_pagelist) { (*pr)("\t\tpage %p, nmissing %d, time %" PRIu32 "\n", ph->ph_page, ph->ph_nmissing, ph->ph_time); #ifdef POOL_CHECK_MAGIC struct pool_item *pi; if (!(pp->pr_roflags & PR_USEBMAP)) { LIST_FOREACH(pi, &ph->ph_itemlist, pi_list) { if (pi->pi_magic != PI_MAGIC) { (*pr)("\t\t\titem %p, magic 0x%x\n", pi, pi->pi_magic); } } } #endif } } static void pool_print1(struct pool *pp, const char *modif, void (*pr)(const char *, ...)) { struct pool_item_header *ph; pool_cache_t pc; pcg_t *pcg; pool_cache_cpu_t *cc; uint64_t cpuhit, cpumiss, pchit, pcmiss; uint32_t nfull; int i; bool print_log = false, print_pagelist = false, print_cache = false; bool print_short = false, skip_empty = false; char c; while ((c = *modif++) != '\0') { if (c == 'l') print_log = true; if (c == 'p') print_pagelist = true; if (c == 'c') print_cache = true; if (c == 's') print_short = true; if (c == 'S') skip_empty = true; } if (skip_empty && pp->pr_nget == 0) return; if ((pc = pp->pr_cache) != NULL) { (*pr)("POOLCACHE"); } else { (*pr)("POOL"); } /* Single line output. */ if (print_short) { (*pr)(" %s:%p:%u:%u:%u:%u:%u:%u:%u:%u:%u:%u\n", pp->pr_wchan, pp, pp->pr_size, pp->pr_align, pp->pr_npages, pp->pr_nitems, pp->pr_nout, pp->pr_nget, pp->pr_nput, pp->pr_npagealloc, pp->pr_npagefree, pp->pr_nidle); return; } (*pr)(" %s: size %u, align %u, ioff %u, roflags 0x%08x\n", pp->pr_wchan, pp->pr_size, pp->pr_align, pp->pr_itemoffset, pp->pr_roflags); (*pr)("\tpool %p, alloc %p\n", pp, pp->pr_alloc); (*pr)("\tminitems %u, minpages %u, maxpages %u, npages %u\n", pp->pr_minitems, pp->pr_minpages, pp->pr_maxpages, pp->pr_npages); (*pr)("\titemsperpage %u, nitems %u, nout %u, hardlimit %u\n", pp->pr_itemsperpage, pp->pr_nitems, pp->pr_nout, pp->pr_hardlimit); (*pr)("\tnget %lu, nfail %lu, nput %lu\n", pp->pr_nget, pp->pr_nfail, pp->pr_nput); (*pr)("\tnpagealloc %lu, npagefree %lu, hiwat %u, nidle %lu\n", pp->pr_npagealloc, pp->pr_npagefree, pp->pr_hiwat, pp->pr_nidle); if (!print_pagelist) goto skip_pagelist; if ((ph = LIST_FIRST(&pp->pr_emptypages)) != NULL) (*pr)("\n\tempty page list:\n"); pool_print_pagelist(pp, &pp->pr_emptypages, pr); if ((ph = LIST_FIRST(&pp->pr_fullpages)) != NULL) (*pr)("\n\tfull page list:\n"); pool_print_pagelist(pp, &pp->pr_fullpages, pr); if ((ph = LIST_FIRST(&pp->pr_partpages)) != NULL) (*pr)("\n\tpartial-page list:\n"); pool_print_pagelist(pp, &pp->pr_partpages, pr); if (pp->pr_curpage == NULL) (*pr)("\tno current page\n"); else (*pr)("\tcurpage %p\n", pp->pr_curpage->ph_page); skip_pagelist: if (print_log) goto skip_log; (*pr)("\n"); skip_log: #define PR_GROUPLIST(pcg) \ (*pr)("\t\tgroup %p: avail %d\n", pcg, pcg->pcg_avail); \ for (i = 0; i < pcg->pcg_size; i++) { \ if (pcg->pcg_objects[i].pcgo_pa != \ POOL_PADDR_INVALID) { \ (*pr)("\t\t\t%p, 0x%llx\n", \ pcg->pcg_objects[i].pcgo_va, \ (unsigned long long) \ pcg->pcg_objects[i].pcgo_pa); \ } else { \ (*pr)("\t\t\t%p\n", \ pcg->pcg_objects[i].pcgo_va); \ } \ } if (pc != NULL) { cpuhit = 0; cpumiss = 0; pcmiss = 0; nfull = 0; for (i = 0; i < __arraycount(pc->pc_cpus); i++) { if ((cc = pc->pc_cpus[i]) == NULL) continue; cpuhit += cc->cc_hits; cpumiss += cc->cc_misses; pcmiss += cc->cc_pcmisses; nfull += cc->cc_nfull; } pchit = cpumiss - pcmiss; (*pr)("\tcpu layer hits %llu misses %llu\n", cpuhit, cpumiss); (*pr)("\tcache layer hits %llu misses %llu\n", pchit, pcmiss); (*pr)("\tcache layer full groups %u\n", nfull); if (print_cache) { (*pr)("\tfull cache groups:\n"); for (pcg = pc->pc_fullgroups; pcg != NULL; pcg = pcg->pcg_next) { PR_GROUPLIST(pcg); } } } #undef PR_GROUPLIST } static int pool_chk_page(struct pool *pp, const char *label, struct pool_item_header *ph) { struct pool_item *pi; void *page; int n; if ((pp->pr_roflags & PR_NOALIGN) == 0) { page = POOL_OBJ_TO_PAGE(pp, ph); if (page != ph->ph_page && (pp->pr_roflags & PR_PHINPAGE) != 0) { if (label != NULL) printf("%s: ", label); printf("pool(%p:%s): page inconsistency: page %p;" " at page head addr %p (p %p)\n", pp, pp->pr_wchan, ph->ph_page, ph, page); return 1; } } if ((pp->pr_roflags & PR_USEBMAP) != 0) return 0; for (pi = LIST_FIRST(&ph->ph_itemlist), n = 0; pi != NULL; pi = LIST_NEXT(pi,pi_list), n++) { #ifdef POOL_CHECK_MAGIC if (pi->pi_magic != PI_MAGIC) { if (label != NULL) printf("%s: ", label); printf("pool(%s): free list modified: magic=%x;" " page %p; item ordinal %d; addr %p\n", pp->pr_wchan, pi->pi_magic, ph->ph_page, n, pi); panic("pool"); } #endif if ((pp->pr_roflags & PR_NOALIGN) != 0) { continue; } page = POOL_OBJ_TO_PAGE(pp, pi); if (page == ph->ph_page) continue; if (label != NULL) printf("%s: ", label); printf("pool(%p:%s): page inconsistency: page %p;" " item ordinal %d; addr %p (p %p)\n", pp, pp->pr_wchan, ph->ph_page, n, pi, page); return 1; } return 0; } int pool_chk(struct pool *pp, const char *label) { struct pool_item_header *ph; int r = 0; mutex_enter(&pp->pr_lock); LIST_FOREACH(ph, &pp->pr_emptypages, ph_pagelist) { r = pool_chk_page(pp, label, ph); if (r) { goto out; } } LIST_FOREACH(ph, &pp->pr_fullpages, ph_pagelist) { r = pool_chk_page(pp, label, ph); if (r) { goto out; } } LIST_FOREACH(ph, &pp->pr_partpages, ph_pagelist) { r = pool_chk_page(pp, label, ph); if (r) { goto out; } } out: mutex_exit(&pp->pr_lock); return r; } /* * pool_cache_init: * * Initialize a pool cache. */ pool_cache_t pool_cache_init(size_t size, u_int align, u_int align_offset, u_int flags, const char *wchan, struct pool_allocator *palloc, int ipl, int (*ctor)(void *, void *, int), void (*dtor)(void *, void *), void *arg) { pool_cache_t pc; pc = pool_get(&cache_pool, PR_WAITOK); if (pc == NULL) return NULL; pool_cache_bootstrap(pc, size, align, align_offset, flags, wchan, palloc, ipl, ctor, dtor, arg); return pc; } /* * pool_cache_bootstrap: * * Kernel-private version of pool_cache_init(). The caller * provides initial storage. */ void pool_cache_bootstrap(pool_cache_t pc, size_t size, u_int align, u_int align_offset, u_int flags, const char *wchan, struct pool_allocator *palloc, int ipl, int (*ctor)(void *, void *, int), void (*dtor)(void *, void *), void *arg) { CPU_INFO_ITERATOR cii; pool_cache_t pc1; struct cpu_info *ci; struct pool *pp; pp = &pc->pc_pool; if (palloc == NULL && ipl == IPL_NONE) { if (size > PAGE_SIZE) { int bigidx = pool_bigidx(size); palloc = &pool_allocator_big[bigidx]; flags |= PR_NOALIGN; } else palloc = &pool_allocator_nointr; } pool_init(pp, size, align, align_offset, flags, wchan, palloc, ipl); if (ctor == NULL) { ctor = NO_CTOR; } if (dtor == NULL) { dtor = NO_DTOR; } pc->pc_fullgroups = NULL; pc->pc_partgroups = NULL; pc->pc_ctor = ctor; pc->pc_dtor = dtor; pc->pc_arg = arg; pc->pc_refcnt = 0; pc->pc_freecheck = NULL; if ((flags & PR_LARGECACHE) != 0) { pc->pc_pcgsize = PCG_NOBJECTS_LARGE; pc->pc_pcgpool = &pcg_large_pool; pc->pc_pcgcache = &pcg_large_cache; } else { pc->pc_pcgsize = PCG_NOBJECTS_NORMAL; pc->pc_pcgpool = &pcg_normal_pool; pc->pc_pcgcache = &pcg_normal_cache; } /* Allocate per-CPU caches. */ memset(pc->pc_cpus, 0, sizeof(pc->pc_cpus)); pc->pc_ncpu = 0; if (ncpu < 2) { /* XXX For sparc: boot CPU is not attached yet. */ pool_cache_cpu_init1(curcpu(), pc); } else { for (CPU_INFO_FOREACH(cii, ci)) { pool_cache_cpu_init1(ci, pc); } } /* Add to list of all pools. */ if (__predict_true(!cold)) mutex_enter(&pool_head_lock); TAILQ_FOREACH(pc1, &pool_cache_head, pc_cachelist) { if (strcmp(pc1->pc_pool.pr_wchan, pc->pc_pool.pr_wchan) > 0) break; } if (pc1 == NULL) TAILQ_INSERT_TAIL(&pool_cache_head, pc, pc_cachelist); else TAILQ_INSERT_BEFORE(pc1, pc, pc_cachelist); if (__predict_true(!cold)) mutex_exit(&pool_head_lock); membar_sync(); pp->pr_cache = pc; } /* * pool_cache_destroy: * * Destroy a pool cache. */ void pool_cache_destroy(pool_cache_t pc) { pool_cache_bootstrap_destroy(pc); pool_put(&cache_pool, pc); } /* * pool_cache_bootstrap_destroy: * * Destroy a pool cache. */ void pool_cache_bootstrap_destroy(pool_cache_t pc) { struct pool *pp = &pc->pc_pool; u_int i; /* Remove it from the global list. */ mutex_enter(&pool_head_lock); while (pc->pc_refcnt != 0) cv_wait(&pool_busy, &pool_head_lock); TAILQ_REMOVE(&pool_cache_head, pc, pc_cachelist); mutex_exit(&pool_head_lock); /* First, invalidate the entire cache. */ pool_cache_invalidate(pc); /* Disassociate it from the pool. */ mutex_enter(&pp->pr_lock); pp->pr_cache = NULL; mutex_exit(&pp->pr_lock); /* Destroy per-CPU data */ for (i = 0; i < __arraycount(pc->pc_cpus); i++) pool_cache_invalidate_cpu(pc, i); /* Finally, destroy it. */ pool_destroy(pp); } /* * pool_cache_cpu_init1: * * Called for each pool_cache whenever a new CPU is attached. */ static void pool_cache_cpu_init1(struct cpu_info *ci, pool_cache_t pc) { pool_cache_cpu_t *cc; int index; index = ci->ci_index; KASSERT(index < __arraycount(pc->pc_cpus)); if ((cc = pc->pc_cpus[index]) != NULL) { return; } /* * The first CPU is 'free'. This needs to be the case for * bootstrap - we may not be able to allocate yet. */ if (pc->pc_ncpu == 0) { cc = &pc->pc_cpu0; pc->pc_ncpu = 1; } else { pc->pc_ncpu++; cc = pool_get(&cache_cpu_pool, PR_WAITOK); } cc->cc_current = __UNCONST(&pcg_dummy); cc->cc_previous = __UNCONST(&pcg_dummy); cc->cc_pcgcache = pc->pc_pcgcache; cc->cc_hits = 0; cc->cc_misses = 0; cc->cc_pcmisses = 0; cc->cc_contended = 0; cc->cc_nfull = 0; cc->cc_npart = 0; pc->pc_cpus[index] = cc; } /* * pool_cache_cpu_init: * * Called whenever a new CPU is attached. */ void pool_cache_cpu_init(struct cpu_info *ci) { pool_cache_t pc; mutex_enter(&pool_head_lock); TAILQ_FOREACH(pc, &pool_cache_head, pc_cachelist) { pc->pc_refcnt++; mutex_exit(&pool_head_lock); pool_cache_cpu_init1(ci, pc); mutex_enter(&pool_head_lock); pc->pc_refcnt--; cv_broadcast(&pool_busy); } mutex_exit(&pool_head_lock); } /* * pool_cache_reclaim: * * Reclaim memory from a pool cache. */ bool pool_cache_reclaim(pool_cache_t pc) { return pool_reclaim(&pc->pc_pool); } static void pool_cache_destruct_object1(pool_cache_t pc, void *object) { (*pc->pc_dtor)(pc->pc_arg, object); pool_put(&pc->pc_pool, object); } /* * pool_cache_destruct_object: * * Force destruction of an object and its release back into * the pool. */ void pool_cache_destruct_object(pool_cache_t pc, void *object) { FREECHECK_IN(&pc->pc_freecheck, object); pool_cache_destruct_object1(pc, object); } /* * pool_cache_invalidate_groups: * * Invalidate a chain of groups and destruct all objects. Return the * number of groups that were invalidated. */ static int pool_cache_invalidate_groups(pool_cache_t pc, pcg_t *pcg) { void *object; pcg_t *next; int i, n; for (n = 0; pcg != NULL; pcg = next, n++) { next = pcg->pcg_next; for (i = 0; i < pcg->pcg_avail; i++) { object = pcg->pcg_objects[i].pcgo_va; pool_cache_destruct_object1(pc, object); } if (pcg->pcg_size == PCG_NOBJECTS_LARGE) { pool_put(&pcg_large_pool, pcg); } else { KASSERT(pcg->pcg_size == PCG_NOBJECTS_NORMAL); pool_put(&pcg_normal_pool, pcg); } } return n; } /* * pool_cache_invalidate: * * Invalidate a pool cache (destruct and release all of the * cached objects). Does not reclaim objects from the pool. * * Note: For pool caches that provide constructed objects, there * is an assumption that another level of synchronization is occurring * between the input to the constructor and the cache invalidation. * * Invalidation is a costly process and should not be called from * interrupt context. */ void pool_cache_invalidate(pool_cache_t pc) { uint64_t where; pcg_t *pcg; int n, s; KASSERT(!cpu_intr_p() && !cpu_softintr_p()); if (ncpu < 2 || !mp_online) { /* * We might be called early enough in the boot process * for the CPU data structures to not be fully initialized. * In this case, transfer the content of the local CPU's * cache back into global cache as only this CPU is currently * running. */ pool_cache_transfer(pc); } else { /* * Signal all CPUs that they must transfer their local * cache back to the global pool then wait for the xcall to * complete. */ where = xc_broadcast(0, __FPTRCAST(xcfunc_t, pool_cache_transfer), pc, NULL); xc_wait(where); } /* Now dequeue and invalidate everything. */ pcg = pool_pcg_trunc(&pcg_normal_cache); (void)pool_cache_invalidate_groups(pc, pcg); pcg = pool_pcg_trunc(&pcg_large_cache); (void)pool_cache_invalidate_groups(pc, pcg); pcg = pool_pcg_trunc(&pc->pc_fullgroups); n = pool_cache_invalidate_groups(pc, pcg); s = splvm(); ((pool_cache_cpu_t *)pc->pc_cpus[curcpu()->ci_index])->cc_nfull -= n; splx(s); pcg = pool_pcg_trunc(&pc->pc_partgroups); n = pool_cache_invalidate_groups(pc, pcg); s = splvm(); ((pool_cache_cpu_t *)pc->pc_cpus[curcpu()->ci_index])->cc_npart -= n; splx(s); } /* * pool_cache_invalidate_cpu: * * Invalidate all CPU-bound cached objects in pool cache, the CPU being * identified by its associated index. * It is caller's responsibility to ensure that no operation is * taking place on this pool cache while doing this invalidation. * WARNING: as no inter-CPU locking is enforced, trying to invalidate * pool cached objects from a CPU different from the one currently running * may result in an undefined behaviour. */ static void pool_cache_invalidate_cpu(pool_cache_t pc, u_int index) { pool_cache_cpu_t *cc; pcg_t *pcg; if ((cc = pc->pc_cpus[index]) == NULL) return; if ((pcg = cc->cc_current) != &pcg_dummy) { pcg->pcg_next = NULL; pool_cache_invalidate_groups(pc, pcg); } if ((pcg = cc->cc_previous) != &pcg_dummy) { pcg->pcg_next = NULL; pool_cache_invalidate_groups(pc, pcg); } if (cc != &pc->pc_cpu0) pool_put(&cache_cpu_pool, cc); } void pool_cache_set_drain_hook(pool_cache_t pc, void (*fn)(void *, int), void *arg) { pool_set_drain_hook(&pc->pc_pool, fn, arg); } void pool_cache_setlowat(pool_cache_t pc, int n) { pool_setlowat(&pc->pc_pool, n); } void pool_cache_sethiwat(pool_cache_t pc, int n) { pool_sethiwat(&pc->pc_pool, n); } void pool_cache_sethardlimit(pool_cache_t pc, int n, const char *warnmess, int ratecap) { pool_sethardlimit(&pc->pc_pool, n, warnmess, ratecap); } void pool_cache_prime(pool_cache_t pc, int n) { pool_prime(&pc->pc_pool, n); } /* * pool_pcg_get: * * Get a cache group from the specified list. Return true if * contention was encountered. Must be called at IPL_VM because * of spin wait vs. kernel_lock. */ static int pool_pcg_get(pcg_t *volatile *head, pcg_t **pcgp) { int count = SPINLOCK_BACKOFF_MIN; pcg_t *o, *n; for (o = atomic_load_relaxed(head);; o = n) { if (__predict_false(o == &pcg_dummy)) { /* Wait for concurrent get to complete. */ SPINLOCK_BACKOFF(count); n = atomic_load_relaxed(head); continue; } if (__predict_false(o == NULL)) { break; } /* Lock out concurrent get/put. */ n = atomic_cas_ptr(head, o, __UNCONST(&pcg_dummy)); if (o == n) { /* Fetch pointer to next item and then unlock. */ #ifndef __HAVE_ATOMIC_AS_MEMBAR membar_datadep_consumer(); /* alpha */ #endif n = atomic_load_relaxed(&o->pcg_next); atomic_store_release(head, n); break; } } *pcgp = o; return count != SPINLOCK_BACKOFF_MIN; } /* * pool_pcg_trunc: * * Chop out entire list of pool cache groups. */ static pcg_t * pool_pcg_trunc(pcg_t *volatile *head) { int count = SPINLOCK_BACKOFF_MIN, s; pcg_t *o, *n; s = splvm(); for (o = atomic_load_relaxed(head);; o = n) { if (__predict_false(o == &pcg_dummy)) { /* Wait for concurrent get to complete. */ SPINLOCK_BACKOFF(count); n = atomic_load_relaxed(head); continue; } n = atomic_cas_ptr(head, o, NULL); if (o == n) { splx(s); #ifndef __HAVE_ATOMIC_AS_MEMBAR membar_datadep_consumer(); /* alpha */ #endif return o; } } } /* * pool_pcg_put: * * Put a pool cache group to the specified list. Return true if * contention was encountered. Must be called at IPL_VM because of * spin wait vs. kernel_lock. */ static int pool_pcg_put(pcg_t *volatile *head, pcg_t *pcg) { int count = SPINLOCK_BACKOFF_MIN; pcg_t *o, *n; for (o = atomic_load_relaxed(head);; o = n) { if (__predict_false(o == &pcg_dummy)) { /* Wait for concurrent get to complete. */ SPINLOCK_BACKOFF(count); n = atomic_load_relaxed(head); continue; } pcg->pcg_next = o; #ifndef __HAVE_ATOMIC_AS_MEMBAR membar_exit(); #endif n = atomic_cas_ptr(head, o, pcg); if (o == n) { return count != SPINLOCK_BACKOFF_MIN; } } } static bool __noinline pool_cache_get_slow(pool_cache_t pc, pool_cache_cpu_t *cc, int s, void **objectp, paddr_t *pap, int flags) { pcg_t *pcg, *cur; void *object; KASSERT(cc->cc_current->pcg_avail == 0); KASSERT(cc->cc_previous->pcg_avail == 0); cc->cc_misses++; /* * If there's a full group, release our empty group back to the * cache. Install the full group as cc_current and return. */ cc->cc_contended += pool_pcg_get(&pc->pc_fullgroups, &pcg); if (__predict_true(pcg != NULL)) { KASSERT(pcg->pcg_avail == pcg->pcg_size); if (__predict_true((cur = cc->cc_current) != &pcg_dummy)) { KASSERT(cur->pcg_avail == 0); (void)pool_pcg_put(cc->cc_pcgcache, cur); } cc->cc_nfull--; cc->cc_current = pcg; return true; } /* * Nothing available locally or in cache. Take the slow * path: fetch a new object from the pool and construct * it. */ cc->cc_pcmisses++; splx(s); object = pool_get(&pc->pc_pool, flags); *objectp = object; if (__predict_false(object == NULL)) { KASSERT((flags & (PR_NOWAIT|PR_LIMITFAIL)) != 0); return false; } if (__predict_false((*pc->pc_ctor)(pc->pc_arg, object, flags) != 0)) { pool_put(&pc->pc_pool, object); *objectp = NULL; return false; } KASSERT((((vaddr_t)object) & (pc->pc_pool.pr_align - 1)) == 0); if (pap != NULL) { #ifdef POOL_VTOPHYS *pap = POOL_VTOPHYS(object); #else *pap = POOL_PADDR_INVALID; #endif } FREECHECK_OUT(&pc->pc_freecheck, object); return false; } /* * pool_cache_get{,_paddr}: * * Get an object from a pool cache (optionally returning * the physical address of the object). */ void * pool_cache_get_paddr(pool_cache_t pc, int flags, paddr_t *pap) { pool_cache_cpu_t *cc; pcg_t *pcg; void *object; int s; KASSERT(!(flags & PR_NOWAIT) != !(flags & PR_WAITOK)); KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()) || (pc->pc_pool.pr_ipl != IPL_NONE || cold || panicstr != NULL), "%s: [%s] is IPL_NONE, but called from interrupt context", __func__, pc->pc_pool.pr_wchan); if (flags & PR_WAITOK) { ASSERT_SLEEPABLE(); } if (flags & PR_NOWAIT) { if (fault_inject()) return NULL; } /* Lock out interrupts and disable preemption. */ s = splvm(); while (/* CONSTCOND */ true) { /* Try and allocate an object from the current group. */ cc = pc->pc_cpus[curcpu()->ci_index]; pcg = cc->cc_current; if (__predict_true(pcg->pcg_avail > 0)) { object = pcg->pcg_objects[--pcg->pcg_avail].pcgo_va; if (__predict_false(pap != NULL)) *pap = pcg->pcg_objects[pcg->pcg_avail].pcgo_pa; #if defined(DIAGNOSTIC) pcg->pcg_objects[pcg->pcg_avail].pcgo_va = NULL; KASSERT(pcg->pcg_avail < pcg->pcg_size); KASSERT(object != NULL); #endif cc->cc_hits++; splx(s); FREECHECK_OUT(&pc->pc_freecheck, object); pool_redzone_fill(&pc->pc_pool, object); pool_cache_get_kmsan(pc, object); return object; } /* * That failed. If the previous group isn't empty, swap * it with the current group and allocate from there. */ pcg = cc->cc_previous; if (__predict_true(pcg->pcg_avail > 0)) { cc->cc_previous = cc->cc_current; cc->cc_current = pcg; continue; } /* * Can't allocate from either group: try the slow path. * If get_slow() allocated an object for us, or if * no more objects are available, it will return false. * Otherwise, we need to retry. */ if (!pool_cache_get_slow(pc, cc, s, &object, pap, flags)) { if (object != NULL) { kmsan_orig(object, pc->pc_pool.pr_size, KMSAN_TYPE_POOL, __RET_ADDR); } break; } } /* * We would like to KASSERT(object || (flags & PR_NOWAIT)), but * pool_cache_get can fail even in the PR_WAITOK case, if the * constructor fails. */ return object; } static bool __noinline pool_cache_put_slow(pool_cache_t pc, pool_cache_cpu_t *cc, int s, void *object) { pcg_t *pcg, *cur; KASSERT(cc->cc_current->pcg_avail == cc->cc_current->pcg_size); KASSERT(cc->cc_previous->pcg_avail == cc->cc_previous->pcg_size); cc->cc_misses++; /* * Try to get an empty group from the cache. If there are no empty * groups in the cache then allocate one. */ (void)pool_pcg_get(cc->cc_pcgcache, &pcg); if (__predict_false(pcg == NULL)) { if (__predict_true(!pool_cache_disable)) { pcg = pool_get(pc->pc_pcgpool, PR_NOWAIT); } if (__predict_true(pcg != NULL)) { pcg->pcg_avail = 0; pcg->pcg_size = pc->pc_pcgsize; } } /* * If there's a empty group, release our full group back to the * cache. Install the empty group to the local CPU and return. */ if (pcg != NULL) { KASSERT(pcg->pcg_avail == 0); if (__predict_false(cc->cc_previous == &pcg_dummy)) { cc->cc_previous = pcg; } else { cur = cc->cc_current; if (__predict_true(cur != &pcg_dummy)) { KASSERT(cur->pcg_avail == cur->pcg_size); cc->cc_contended += pool_pcg_put(&pc->pc_fullgroups, cur); cc->cc_nfull++; } cc->cc_current = pcg; } return true; } /* * Nothing available locally or in cache, and we didn't * allocate an empty group. Take the slow path and destroy * the object here and now. */ cc->cc_pcmisses++; splx(s); pool_cache_destruct_object(pc, object); return false; } /* * pool_cache_put{,_paddr}: * * Put an object back to the pool cache (optionally caching the * physical address of the object). */ void pool_cache_put_paddr(pool_cache_t pc, void *object, paddr_t pa) { pool_cache_cpu_t *cc; pcg_t *pcg; int s; KASSERT(object != NULL); pool_cache_put_kmsan(pc, object); pool_cache_redzone_check(pc, object); FREECHECK_IN(&pc->pc_freecheck, object); if (pc->pc_pool.pr_roflags & PR_PHINPAGE) { pc_phinpage_check(pc, object); } if (pool_cache_put_nocache(pc, object)) { return; } /* Lock out interrupts and disable preemption. */ s = splvm(); while (/* CONSTCOND */ true) { /* If the current group isn't full, release it there. */ cc = pc->pc_cpus[curcpu()->ci_index]; pcg = cc->cc_current; if (__predict_true(pcg->pcg_avail < pcg->pcg_size)) { pcg->pcg_objects[pcg->pcg_avail].pcgo_va = object; pcg->pcg_objects[pcg->pcg_avail].pcgo_pa = pa; pcg->pcg_avail++; cc->cc_hits++; splx(s); return; } /* * That failed. If the previous group isn't full, swap * it with the current group and try again. */ pcg = cc->cc_previous; if (__predict_true(pcg->pcg_avail < pcg->pcg_size)) { cc->cc_previous = cc->cc_current; cc->cc_current = pcg; continue; } /* * Can't free to either group: try the slow path. * If put_slow() releases the object for us, it * will return false. Otherwise we need to retry. */ if (!pool_cache_put_slow(pc, cc, s, object)) break; } } /* * pool_cache_transfer: * * Transfer objects from the per-CPU cache to the global cache. * Run within a cross-call thread. */ static void pool_cache_transfer(pool_cache_t pc) { pool_cache_cpu_t *cc; pcg_t *prev, *cur; int s; s = splvm(); cc = pc->pc_cpus[curcpu()->ci_index]; cur = cc->cc_current; cc->cc_current = __UNCONST(&pcg_dummy); prev = cc->cc_previous; cc->cc_previous = __UNCONST(&pcg_dummy); if (cur != &pcg_dummy) { if (cur->pcg_avail == cur->pcg_size) { (void)pool_pcg_put(&pc->pc_fullgroups, cur); cc->cc_nfull++; } else if (cur->pcg_avail == 0) { (void)pool_pcg_put(pc->pc_pcgcache, cur); } else { (void)pool_pcg_put(&pc->pc_partgroups, cur); cc->cc_npart++; } } if (prev != &pcg_dummy) { if (prev->pcg_avail == prev->pcg_size) { (void)pool_pcg_put(&pc->pc_fullgroups, prev); cc->cc_nfull++; } else if (prev->pcg_avail == 0) { (void)pool_pcg_put(pc->pc_pcgcache, prev); } else { (void)pool_pcg_put(&pc->pc_partgroups, prev); cc->cc_npart++; } } splx(s); } static int pool_bigidx(size_t size) { int i; for (i = 0; i < __arraycount(pool_allocator_big); i++) { if (1 << (i + POOL_ALLOCATOR_BIG_BASE) >= size) return i; } panic("pool item size %zu too large, use a custom allocator", size); } static void * pool_allocator_alloc(struct pool *pp, int flags) { struct pool_allocator *pa = pp->pr_alloc; void *res; res = (*pa->pa_alloc)(pp, flags); if (res == NULL && (flags & PR_WAITOK) == 0) { /* * We only run the drain hook here if PR_NOWAIT. * In other cases, the hook will be run in * pool_reclaim(). */ if (pp->pr_drain_hook != NULL) { (*pp->pr_drain_hook)(pp->pr_drain_hook_arg, flags); res = (*pa->pa_alloc)(pp, flags); } } return res; } static void pool_allocator_free(struct pool *pp, void *v) { struct pool_allocator *pa = pp->pr_alloc; if (pp->pr_redzone) { kasan_mark(v, pa->pa_pagesz, pa->pa_pagesz, 0); } (*pa->pa_free)(pp, v); } void * pool_page_alloc(struct pool *pp, int flags) { const vm_flag_t vflags = (flags & PR_WAITOK) ? VM_SLEEP: VM_NOSLEEP; vmem_addr_t va; int ret; ret = uvm_km_kmem_alloc(kmem_va_arena, pp->pr_alloc->pa_pagesz, vflags | VM_INSTANTFIT, &va); return ret ? NULL : (void *)va; } void pool_page_free(struct pool *pp, void *v) { uvm_km_kmem_free(kmem_va_arena, (vaddr_t)v, pp->pr_alloc->pa_pagesz); } static void * pool_page_alloc_meta(struct pool *pp, int flags) { const vm_flag_t vflags = (flags & PR_WAITOK) ? VM_SLEEP: VM_NOSLEEP; vmem_addr_t va; int ret; ret = vmem_alloc(kmem_meta_arena, pp->pr_alloc->pa_pagesz, vflags | VM_INSTANTFIT, &va); return ret ? NULL : (void *)va; } static void pool_page_free_meta(struct pool *pp, void *v) { vmem_free(kmem_meta_arena, (vmem_addr_t)v, pp->pr_alloc->pa_pagesz); } #ifdef KMSAN static inline void pool_get_kmsan(struct pool *pp, void *p) { kmsan_orig(p, pp->pr_size, KMSAN_TYPE_POOL, __RET_ADDR); kmsan_mark(p, pp->pr_size, KMSAN_STATE_UNINIT); } static inline void pool_put_kmsan(struct pool *pp, void *p) { kmsan_mark(p, pp->pr_size, KMSAN_STATE_INITED); } static inline void pool_cache_get_kmsan(pool_cache_t pc, void *p) { if (__predict_false(pc_has_ctor(pc))) { return; } pool_get_kmsan(&pc->pc_pool, p); } static inline void pool_cache_put_kmsan(pool_cache_t pc, void *p) { pool_put_kmsan(&pc->pc_pool, p); } #endif #ifdef POOL_QUARANTINE static void pool_quarantine_init(struct pool *pp) { pp->pr_quar.rotor = 0; memset(&pp->pr_quar, 0, sizeof(pp->pr_quar)); } static void pool_quarantine_flush(struct pool *pp) { pool_quar_t *quar = &pp->pr_quar; struct pool_pagelist pq; size_t i; LIST_INIT(&pq); mutex_enter(&pp->pr_lock); for (i = 0; i < POOL_QUARANTINE_DEPTH; i++) { if (quar->list[i] == 0) continue; pool_do_put(pp, (void *)quar->list[i], &pq); } mutex_exit(&pp->pr_lock); pr_pagelist_free(pp, &pq); } static bool pool_put_quarantine(struct pool *pp, void *v, struct pool_pagelist *pq) { pool_quar_t *quar = &pp->pr_quar; uintptr_t old; if (pp->pr_roflags & PR_NOTOUCH) { return false; } pool_redzone_check(pp, v); old = quar->list[quar->rotor]; quar->list[quar->rotor] = (uintptr_t)v; quar->rotor = (quar->rotor + 1) % POOL_QUARANTINE_DEPTH; if (old != 0) { pool_do_put(pp, (void *)old, pq); } return true; } #endif #ifdef POOL_NOCACHE static bool pool_cache_put_nocache(pool_cache_t pc, void *p) { pool_cache_destruct_object(pc, p); return true; } #endif #ifdef POOL_REDZONE #if defined(_LP64) # define PRIME 0x9e37fffffffc0000UL #else /* defined(_LP64) */ # define PRIME 0x9e3779b1 #endif /* defined(_LP64) */ #define STATIC_BYTE 0xFE CTASSERT(POOL_REDZONE_SIZE > 1); #ifndef KASAN static inline uint8_t pool_pattern_generate(const void *p) { return (uint8_t)(((uintptr_t)p) * PRIME >> ((sizeof(uintptr_t) - sizeof(uint8_t))) * CHAR_BIT); } #endif static void pool_redzone_init(struct pool *pp, size_t requested_size) { size_t redzsz; size_t nsz; #ifdef KASAN redzsz = requested_size; kasan_add_redzone(&redzsz); redzsz -= requested_size; #else redzsz = POOL_REDZONE_SIZE; #endif if (pp->pr_roflags & PR_NOTOUCH) { pp->pr_redzone = false; return; } /* * We may have extended the requested size earlier; check if * there's naturally space in the padding for a red zone. */ if (pp->pr_size - requested_size >= redzsz) { pp->pr_reqsize_with_redzone = requested_size + redzsz; pp->pr_redzone = true; return; } /* * No space in the natural padding; check if we can extend a * bit the size of the pool. * * Avoid using redzone for allocations half of a page or larger. * For pagesize items, we'd waste a whole new page (could be * unmapped?), and for half pagesize items, approximately half * the space is lost (eg, 4K pages, you get one 2K allocation.) */ nsz = roundup(pp->pr_size + redzsz, pp->pr_align); if (nsz <= (pp->pr_alloc->pa_pagesz / 2)) { /* Ok, we can */ pp->pr_size = nsz; pp->pr_reqsize_with_redzone = requested_size + redzsz; pp->pr_redzone = true; } else { /* No space for a red zone... snif :'( */ pp->pr_redzone = false; aprint_debug("pool redzone disabled for '%s'\n", pp->pr_wchan); } } static void pool_redzone_fill(struct pool *pp, void *p) { if (!pp->pr_redzone) return; #ifdef KASAN kasan_mark(p, pp->pr_reqsize, pp->pr_reqsize_with_redzone, KASAN_POOL_REDZONE); #else uint8_t *cp, pat; const uint8_t *ep; cp = (uint8_t *)p + pp->pr_reqsize; ep = cp + POOL_REDZONE_SIZE; /* * We really don't want the first byte of the red zone to be '\0'; * an off-by-one in a string may not be properly detected. */ pat = pool_pattern_generate(cp); *cp = (pat == '\0') ? STATIC_BYTE: pat; cp++; while (cp < ep) { *cp = pool_pattern_generate(cp); cp++; } #endif } static void pool_redzone_check(struct pool *pp, void *p) { if (!pp->pr_redzone) return; #ifdef KASAN kasan_mark(p, 0, pp->pr_reqsize_with_redzone, KASAN_POOL_FREED); #else uint8_t *cp, pat, expected; const uint8_t *ep; cp = (uint8_t *)p + pp->pr_reqsize; ep = cp + POOL_REDZONE_SIZE; pat = pool_pattern_generate(cp); expected = (pat == '\0') ? STATIC_BYTE: pat; if (__predict_false(*cp != expected)) { panic("%s: [%s] 0x%02x != 0x%02x", __func__, pp->pr_wchan, *cp, expected); } cp++; while (cp < ep) { expected = pool_pattern_generate(cp); if (__predict_false(*cp != expected)) { panic("%s: [%s] 0x%02x != 0x%02x", __func__, pp->pr_wchan, *cp, expected); } cp++; } #endif } static void pool_cache_redzone_check(pool_cache_t pc, void *p) { #ifdef KASAN /* If there is a ctor/dtor, leave the data as valid. */ if (__predict_false(pc_has_ctor(pc) || pc_has_dtor(pc))) { return; } #endif pool_redzone_check(&pc->pc_pool, p); } #endif /* POOL_REDZONE */ #if defined(DDB) static bool pool_in_page(struct pool *pp, struct pool_item_header *ph, uintptr_t addr) { return (uintptr_t)ph->ph_page <= addr && addr < (uintptr_t)ph->ph_page + pp->pr_alloc->pa_pagesz; } static bool pool_in_item(struct pool *pp, void *item, uintptr_t addr) { return (uintptr_t)item <= addr && addr < (uintptr_t)item + pp->pr_size; } static bool pool_in_cg(struct pool *pp, struct pool_cache_group *pcg, uintptr_t addr) { int i; if (pcg == NULL) { return false; } for (i = 0; i < pcg->pcg_avail; i++) { if (pool_in_item(pp, pcg->pcg_objects[i].pcgo_va, addr)) { return true; } } return false; } static bool pool_allocated(struct pool *pp, struct pool_item_header *ph, uintptr_t addr) { if ((pp->pr_roflags & PR_USEBMAP) != 0) { unsigned int idx = pr_item_bitmap_index(pp, ph, (void *)addr); pool_item_bitmap_t *bitmap = ph->ph_bitmap + (idx / BITMAP_SIZE); pool_item_bitmap_t mask = 1 << (idx & BITMAP_MASK); return (*bitmap & mask) == 0; } else { struct pool_item *pi; LIST_FOREACH(pi, &ph->ph_itemlist, pi_list) { if (pool_in_item(pp, pi, addr)) { return false; } } return true; } } void pool_whatis(uintptr_t addr, void (*pr)(const char *, ...)) { struct pool *pp; TAILQ_FOREACH(pp, &pool_head, pr_poollist) { struct pool_item_header *ph; uintptr_t item; bool allocated = true; bool incache = false; bool incpucache = false; char cpucachestr[32]; if ((pp->pr_roflags & PR_PHINPAGE) != 0) { LIST_FOREACH(ph, &pp->pr_fullpages, ph_pagelist) { if (pool_in_page(pp, ph, addr)) { goto found; } } LIST_FOREACH(ph, &pp->pr_partpages, ph_pagelist) { if (pool_in_page(pp, ph, addr)) { allocated = pool_allocated(pp, ph, addr); goto found; } } LIST_FOREACH(ph, &pp->pr_emptypages, ph_pagelist) { if (pool_in_page(pp, ph, addr)) { allocated = false; goto found; } } continue; } else { ph = pr_find_pagehead_noalign(pp, (void *)addr); if (ph == NULL || !pool_in_page(pp, ph, addr)) { continue; } allocated = pool_allocated(pp, ph, addr); } found: if (allocated && pp->pr_cache) { pool_cache_t pc = pp->pr_cache; struct pool_cache_group *pcg; int i; for (pcg = pc->pc_fullgroups; pcg != NULL; pcg = pcg->pcg_next) { if (pool_in_cg(pp, pcg, addr)) { incache = true; goto print; } } for (i = 0; i < __arraycount(pc->pc_cpus); i++) { pool_cache_cpu_t *cc; if ((cc = pc->pc_cpus[i]) == NULL) { continue; } if (pool_in_cg(pp, cc->cc_current, addr) || pool_in_cg(pp, cc->cc_previous, addr)) { struct cpu_info *ci = cpu_lookup(i); incpucache = true; snprintf(cpucachestr, sizeof(cpucachestr), "cached by CPU %u", ci->ci_index); goto print; } } } print: item = (uintptr_t)ph->ph_page + ph->ph_off; item = item + rounddown(addr - item, pp->pr_size); (*pr)("%p is %p+%zu in POOL '%s' (%s)\n", (void *)addr, item, (size_t)(addr - item), pp->pr_wchan, incpucache ? cpucachestr : incache ? "cached" : allocated ? "allocated" : "free"); } } #endif /* defined(DDB) */ static int pool_sysctl(SYSCTLFN_ARGS) { struct pool_sysctl data; struct pool *pp; struct pool_cache *pc; pool_cache_cpu_t *cc; int error; size_t i, written; if (oldp == NULL) { *oldlenp = 0; TAILQ_FOREACH(pp, &pool_head, pr_poollist) *oldlenp += sizeof(data); return 0; } memset(&data, 0, sizeof(data)); error = 0; written = 0; TAILQ_FOREACH(pp, &pool_head, pr_poollist) { if (written + sizeof(data) > *oldlenp) break; strlcpy(data.pr_wchan, pp->pr_wchan, sizeof(data.pr_wchan)); data.pr_pagesize = pp->pr_alloc->pa_pagesz; data.pr_flags = pp->pr_roflags | pp->pr_flags; #define COPY(field) data.field = pp->field COPY(pr_size); COPY(pr_itemsperpage); COPY(pr_nitems); COPY(pr_nout); COPY(pr_hardlimit); COPY(pr_npages); COPY(pr_minpages); COPY(pr_maxpages); COPY(pr_nget); COPY(pr_nfail); COPY(pr_nput); COPY(pr_npagealloc); COPY(pr_npagefree); COPY(pr_hiwat); COPY(pr_nidle); #undef COPY data.pr_cache_nmiss_pcpu = 0; data.pr_cache_nhit_pcpu = 0; data.pr_cache_nmiss_global = 0; data.pr_cache_nempty = 0; data.pr_cache_ncontended = 0; data.pr_cache_npartial = 0; if (pp->pr_cache) { uint32_t nfull = 0; pc = pp->pr_cache; data.pr_cache_meta_size = pc->pc_pcgsize; for (i = 0; i < pc->pc_ncpu; ++i) { cc = pc->pc_cpus[i]; if (cc == NULL) continue; data.pr_cache_ncontended += cc->cc_contended; data.pr_cache_nmiss_pcpu += cc->cc_misses; data.pr_cache_nhit_pcpu += cc->cc_hits; data.pr_cache_nmiss_global += cc->cc_pcmisses; nfull += cc->cc_nfull; /* 32-bit rollover! */ data.pr_cache_npartial += cc->cc_npart; } data.pr_cache_nfull = nfull; } else { data.pr_cache_meta_size = 0; data.pr_cache_nfull = 0; } data.pr_cache_nhit_global = data.pr_cache_nmiss_pcpu - data.pr_cache_nmiss_global; error = sysctl_copyout(l, &data, oldp, sizeof(data)); if (error) break; written += sizeof(data); oldp = (char *)oldp + sizeof(data); } *oldlenp = written; return error; } SYSCTL_SETUP(sysctl_pool_setup, "sysctl kern.pool setup") { const struct sysctlnode *rnode = NULL; sysctl_createv(clog, 0, NULL, &rnode, CTLFLAG_PERMANENT, CTLTYPE_STRUCT, "pool", SYSCTL_DESCR("Get pool statistics"), pool_sysctl, 0, NULL, 0, CTL_KERN, CTL_CREATE, CTL_EOL); }