/*- * Copyright (c) 2002-2005, 2009 Jeffrey Roberson * Copyright (c) 2004, 2005 Bosko Milekic * Copyright (c) 2004-2006 Robert N. M. Watson * All rights reserved. * * 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 unmodified, 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 AUTHOR ``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 AUTHOR 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. */ /* * uma_core.c Implementation of the Universal Memory allocator * * This allocator is intended to replace the multitude of similar object caches * in the standard FreeBSD kernel. The intent is to be flexible as well as * effecient. A primary design goal is to return unused memory to the rest of * the system. This will make the system as a whole more flexible due to the * ability to move memory to subsystems which most need it instead of leaving * pools of reserved memory unused. * * The basic ideas stem from similar slab/zone based allocators whose algorithms * are well known. * */ /* * TODO: * - Improve memory usage for large allocations * - Investigate cache size adjustments */ #include __FBSDID("$FreeBSD$"); /* I should really use ktr.. */ /* #define UMA_DEBUG 1 #define UMA_DEBUG_ALLOC 1 #define UMA_DEBUG_ALLOC_1 1 */ #include "opt_ddb.h" #include "opt_param.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * This is the zone and keg from which all zones are spawned. The idea is that * even the zone & keg heads are allocated from the allocator, so we use the * bss section to bootstrap us. */ static struct uma_keg masterkeg; static struct uma_zone masterzone_k; static struct uma_zone masterzone_z; static uma_zone_t kegs = &masterzone_k; static uma_zone_t zones = &masterzone_z; /* This is the zone from which all of uma_slab_t's are allocated. */ static uma_zone_t slabzone; static uma_zone_t slabrefzone; /* With refcounters (for UMA_ZONE_REFCNT) */ /* * The initial hash tables come out of this zone so they can be allocated * prior to malloc coming up. */ static uma_zone_t hashzone; /* The boot-time adjusted value for cache line alignment. */ static int uma_align_cache = 64 - 1; static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets"); /* * Are we allowed to allocate buckets? */ static int bucketdisable = 1; /* Linked list of all kegs in the system */ static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs); /* This mutex protects the keg list */ static struct mtx uma_mtx; /* Linked list of boot time pages */ static LIST_HEAD(,uma_slab) uma_boot_pages = LIST_HEAD_INITIALIZER(uma_boot_pages); /* This mutex protects the boot time pages list */ static struct mtx uma_boot_pages_mtx; /* Is the VM done starting up? */ static int booted = 0; /* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */ static u_int uma_max_ipers; static u_int uma_max_ipers_ref; /* * This is the handle used to schedule events that need to happen * outside of the allocation fast path. */ static struct callout uma_callout; #define UMA_TIMEOUT 20 /* Seconds for callout interval. */ /* * This structure is passed as the zone ctor arg so that I don't have to create * a special allocation function just for zones. */ struct uma_zctor_args { char *name; size_t size; uma_ctor ctor; uma_dtor dtor; uma_init uminit; uma_fini fini; uma_keg_t keg; int align; u_int32_t flags; }; struct uma_kctor_args { uma_zone_t zone; size_t size; uma_init uminit; uma_fini fini; int align; u_int32_t flags; }; struct uma_bucket_zone { uma_zone_t ubz_zone; char *ubz_name; int ubz_entries; }; #define BUCKET_MAX 128 struct uma_bucket_zone bucket_zones[] = { { NULL, "16 Bucket", 16 }, { NULL, "32 Bucket", 32 }, { NULL, "64 Bucket", 64 }, { NULL, "128 Bucket", 128 }, { NULL, NULL, 0} }; #define BUCKET_SHIFT 4 #define BUCKET_ZONES ((BUCKET_MAX >> BUCKET_SHIFT) + 1) /* * bucket_size[] maps requested bucket sizes to zones that allocate a bucket * of approximately the right size. */ static uint8_t bucket_size[BUCKET_ZONES]; /* * Flags and enumerations to be passed to internal functions. */ enum zfreeskip { SKIP_NONE, SKIP_DTOR, SKIP_FINI }; #define ZFREE_STATFAIL 0x00000001 /* Update zone failure statistic. */ #define ZFREE_STATFREE 0x00000002 /* Update zone free statistic. */ /* Prototypes.. */ static void *obj_alloc(uma_zone_t, int, u_int8_t *, int); static void *page_alloc(uma_zone_t, int, u_int8_t *, int); static void *startup_alloc(uma_zone_t, int, u_int8_t *, int); static void page_free(void *, int, u_int8_t); static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int); static void cache_drain(uma_zone_t); static void bucket_drain(uma_zone_t, uma_bucket_t); static void bucket_cache_drain(uma_zone_t zone); static int keg_ctor(void *, int, void *, int); static void keg_dtor(void *, int, void *); static int zone_ctor(void *, int, void *, int); static void zone_dtor(void *, int, void *); static int zero_init(void *, int, int); static void keg_small_init(uma_keg_t keg); static void keg_large_init(uma_keg_t keg); static void zone_foreach(void (*zfunc)(uma_zone_t)); static void zone_timeout(uma_zone_t zone); static int hash_alloc(struct uma_hash *); static int hash_expand(struct uma_hash *, struct uma_hash *); static void hash_free(struct uma_hash *hash); static void uma_timeout(void *); static void uma_startup3(void); static void *zone_alloc_item(uma_zone_t, void *, int); static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip, int); static void bucket_enable(void); static void bucket_init(void); static uma_bucket_t bucket_alloc(int, int); static void bucket_free(uma_bucket_t); static void bucket_zone_drain(void); static int zone_alloc_bucket(uma_zone_t zone, int flags); static uma_slab_t zone_fetch_slab(uma_zone_t zone, uma_keg_t last, int flags); static uma_slab_t zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int flags); static void *slab_alloc_item(uma_zone_t zone, uma_slab_t slab); static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini, int align, u_int32_t flags); static inline void zone_relock(uma_zone_t zone, uma_keg_t keg); static inline void keg_relock(uma_keg_t keg, uma_zone_t zone); void uma_print_zone(uma_zone_t); void uma_print_stats(void); static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS); static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS); SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL); SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT, 0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones"); SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT, 0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats"); /* * This routine checks to see whether or not it's safe to enable buckets. */ static void bucket_enable(void) { if (cnt.v_free_count < cnt.v_free_min) bucketdisable = 1; else bucketdisable = 0; } /* * Initialize bucket_zones, the array of zones of buckets of various sizes. * * For each zone, calculate the memory required for each bucket, consisting * of the header and an array of pointers. Initialize bucket_size[] to point * the range of appropriate bucket sizes at the zone. */ static void bucket_init(void) { struct uma_bucket_zone *ubz; int i; int j; for (i = 0, j = 0; bucket_zones[j].ubz_entries != 0; j++) { int size; ubz = &bucket_zones[j]; size = roundup(sizeof(struct uma_bucket), sizeof(void *)); size += sizeof(void *) * ubz->ubz_entries; ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size, NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL | UMA_ZFLAG_BUCKET); for (; i <= ubz->ubz_entries; i += (1 << BUCKET_SHIFT)) bucket_size[i >> BUCKET_SHIFT] = j; } } /* * Given a desired number of entries for a bucket, return the zone from which * to allocate the bucket. */ static struct uma_bucket_zone * bucket_zone_lookup(int entries) { int idx; idx = howmany(entries, 1 << BUCKET_SHIFT); return (&bucket_zones[bucket_size[idx]]); } static uma_bucket_t bucket_alloc(int entries, int bflags) { struct uma_bucket_zone *ubz; uma_bucket_t bucket; /* * This is to stop us from allocating per cpu buckets while we're * running out of vm.boot_pages. Otherwise, we would exhaust the * boot pages. This also prevents us from allocating buckets in * low memory situations. */ if (bucketdisable) return (NULL); ubz = bucket_zone_lookup(entries); bucket = zone_alloc_item(ubz->ubz_zone, NULL, bflags); if (bucket) { #ifdef INVARIANTS bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries); #endif bucket->ub_cnt = 0; bucket->ub_entries = ubz->ubz_entries; } return (bucket); } static void bucket_free(uma_bucket_t bucket) { struct uma_bucket_zone *ubz; ubz = bucket_zone_lookup(bucket->ub_entries); zone_free_item(ubz->ubz_zone, bucket, NULL, SKIP_NONE, ZFREE_STATFREE); } static void bucket_zone_drain(void) { struct uma_bucket_zone *ubz; for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) zone_drain(ubz->ubz_zone); } static inline uma_keg_t zone_first_keg(uma_zone_t zone) { return (LIST_FIRST(&zone->uz_kegs)->kl_keg); } static void zone_foreach_keg(uma_zone_t zone, void (*kegfn)(uma_keg_t)) { uma_klink_t klink; LIST_FOREACH(klink, &zone->uz_kegs, kl_link) kegfn(klink->kl_keg); } /* * Routine called by timeout which is used to fire off some time interval * based calculations. (stats, hash size, etc.) * * Arguments: * arg Unused * * Returns: * Nothing */ static void uma_timeout(void *unused) { bucket_enable(); zone_foreach(zone_timeout); /* Reschedule this event */ callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL); } /* * Routine to perform timeout driven calculations. This expands the * hashes and does per cpu statistics aggregation. * * Returns nothing. */ static void keg_timeout(uma_keg_t keg) { KEG_LOCK(keg); /* * Expand the keg hash table. * * This is done if the number of slabs is larger than the hash size. * What I'm trying to do here is completely reduce collisions. This * may be a little aggressive. Should I allow for two collisions max? */ if (keg->uk_flags & UMA_ZONE_HASH && keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) { struct uma_hash newhash; struct uma_hash oldhash; int ret; /* * This is so involved because allocating and freeing * while the keg lock is held will lead to deadlock. * I have to do everything in stages and check for * races. */ newhash = keg->uk_hash; KEG_UNLOCK(keg); ret = hash_alloc(&newhash); KEG_LOCK(keg); if (ret) { if (hash_expand(&keg->uk_hash, &newhash)) { oldhash = keg->uk_hash; keg->uk_hash = newhash; } else oldhash = newhash; KEG_UNLOCK(keg); hash_free(&oldhash); KEG_LOCK(keg); } } KEG_UNLOCK(keg); } static void zone_timeout(uma_zone_t zone) { zone_foreach_keg(zone, &keg_timeout); } /* * Allocate and zero fill the next sized hash table from the appropriate * backing store. * * Arguments: * hash A new hash structure with the old hash size in uh_hashsize * * Returns: * 1 on sucess and 0 on failure. */ static int hash_alloc(struct uma_hash *hash) { int oldsize; int alloc; oldsize = hash->uh_hashsize; /* We're just going to go to a power of two greater */ if (oldsize) { hash->uh_hashsize = oldsize * 2; alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize; hash->uh_slab_hash = (struct slabhead *)malloc(alloc, M_UMAHASH, M_NOWAIT); } else { alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT; hash->uh_slab_hash = zone_alloc_item(hashzone, NULL, M_WAITOK); hash->uh_hashsize = UMA_HASH_SIZE_INIT; } if (hash->uh_slab_hash) { bzero(hash->uh_slab_hash, alloc); hash->uh_hashmask = hash->uh_hashsize - 1; return (1); } return (0); } /* * Expands the hash table for HASH zones. This is done from zone_timeout * to reduce collisions. This must not be done in the regular allocation * path, otherwise, we can recurse on the vm while allocating pages. * * Arguments: * oldhash The hash you want to expand * newhash The hash structure for the new table * * Returns: * Nothing * * Discussion: */ static int hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash) { uma_slab_t slab; int hval; int i; if (!newhash->uh_slab_hash) return (0); if (oldhash->uh_hashsize >= newhash->uh_hashsize) return (0); /* * I need to investigate hash algorithms for resizing without a * full rehash. */ for (i = 0; i < oldhash->uh_hashsize; i++) while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) { slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]); SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink); hval = UMA_HASH(newhash, slab->us_data); SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval], slab, us_hlink); } return (1); } /* * Free the hash bucket to the appropriate backing store. * * Arguments: * slab_hash The hash bucket we're freeing * hashsize The number of entries in that hash bucket * * Returns: * Nothing */ static void hash_free(struct uma_hash *hash) { if (hash->uh_slab_hash == NULL) return; if (hash->uh_hashsize == UMA_HASH_SIZE_INIT) zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE, ZFREE_STATFREE); else free(hash->uh_slab_hash, M_UMAHASH); } /* * Frees all outstanding items in a bucket * * Arguments: * zone The zone to free to, must be unlocked. * bucket The free/alloc bucket with items, cpu queue must be locked. * * Returns: * Nothing */ static void bucket_drain(uma_zone_t zone, uma_bucket_t bucket) { void *item; if (bucket == NULL) return; while (bucket->ub_cnt > 0) { bucket->ub_cnt--; item = bucket->ub_bucket[bucket->ub_cnt]; #ifdef INVARIANTS bucket->ub_bucket[bucket->ub_cnt] = NULL; KASSERT(item != NULL, ("bucket_drain: botched ptr, item is NULL")); #endif zone_free_item(zone, item, NULL, SKIP_DTOR, 0); } } /* * Drains the per cpu caches for a zone. * * NOTE: This may only be called while the zone is being turn down, and not * during normal operation. This is necessary in order that we do not have * to migrate CPUs to drain the per-CPU caches. * * Arguments: * zone The zone to drain, must be unlocked. * * Returns: * Nothing */ static void cache_drain(uma_zone_t zone) { uma_cache_t cache; int cpu; /* * XXX: It is safe to not lock the per-CPU caches, because we're * tearing down the zone anyway. I.e., there will be no further use * of the caches at this point. * * XXX: It would good to be able to assert that the zone is being * torn down to prevent improper use of cache_drain(). * * XXX: We lock the zone before passing into bucket_cache_drain() as * it is used elsewhere. Should the tear-down path be made special * there in some form? */ CPU_FOREACH(cpu) { cache = &zone->uz_cpu[cpu]; bucket_drain(zone, cache->uc_allocbucket); bucket_drain(zone, cache->uc_freebucket); if (cache->uc_allocbucket != NULL) bucket_free(cache->uc_allocbucket); if (cache->uc_freebucket != NULL) bucket_free(cache->uc_freebucket); cache->uc_allocbucket = cache->uc_freebucket = NULL; } ZONE_LOCK(zone); bucket_cache_drain(zone); ZONE_UNLOCK(zone); } /* * Drain the cached buckets from a zone. Expects a locked zone on entry. */ static void bucket_cache_drain(uma_zone_t zone) { uma_bucket_t bucket; /* * Drain the bucket queues and free the buckets, we just keep two per * cpu (alloc/free). */ while ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) { LIST_REMOVE(bucket, ub_link); ZONE_UNLOCK(zone); bucket_drain(zone, bucket); bucket_free(bucket); ZONE_LOCK(zone); } /* Now we do the free queue.. */ while ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) { LIST_REMOVE(bucket, ub_link); bucket_free(bucket); } } /* * Frees pages from a keg back to the system. This is done on demand from * the pageout daemon. * * Returns nothing. */ static void keg_drain(uma_keg_t keg) { struct slabhead freeslabs = { 0 }; uma_slab_t slab; uma_slab_t n; u_int8_t flags; u_int8_t *mem; int i; /* * We don't want to take pages from statically allocated kegs at this * time */ if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL) return; #ifdef UMA_DEBUG printf("%s free items: %u\n", keg->uk_name, keg->uk_free); #endif KEG_LOCK(keg); if (keg->uk_free == 0) goto finished; slab = LIST_FIRST(&keg->uk_free_slab); while (slab) { n = LIST_NEXT(slab, us_link); /* We have no where to free these to */ if (slab->us_flags & UMA_SLAB_BOOT) { slab = n; continue; } LIST_REMOVE(slab, us_link); keg->uk_pages -= keg->uk_ppera; keg->uk_free -= keg->uk_ipers; if (keg->uk_flags & UMA_ZONE_HASH) UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data); SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink); slab = n; } finished: KEG_UNLOCK(keg); while ((slab = SLIST_FIRST(&freeslabs)) != NULL) { SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink); if (keg->uk_fini) for (i = 0; i < keg->uk_ipers; i++) keg->uk_fini( slab->us_data + (keg->uk_rsize * i), keg->uk_size); flags = slab->us_flags; mem = slab->us_data; if (keg->uk_flags & UMA_ZONE_VTOSLAB) { vm_object_t obj; if (flags & UMA_SLAB_KMEM) obj = kmem_object; else if (flags & UMA_SLAB_KERNEL) obj = kernel_object; else obj = NULL; for (i = 0; i < keg->uk_ppera; i++) vsetobj((vm_offset_t)mem + (i * PAGE_SIZE), obj); } if (keg->uk_flags & UMA_ZONE_OFFPAGE) zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE); #ifdef UMA_DEBUG printf("%s: Returning %d bytes.\n", keg->uk_name, UMA_SLAB_SIZE * keg->uk_ppera); #endif keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera, flags); } } static void zone_drain_wait(uma_zone_t zone, int waitok) { /* * Set draining to interlock with zone_dtor() so we can release our * locks as we go. Only dtor() should do a WAITOK call since it * is the only call that knows the structure will still be available * when it wakes up. */ ZONE_LOCK(zone); while (zone->uz_flags & UMA_ZFLAG_DRAINING) { if (waitok == M_NOWAIT) goto out; mtx_unlock(&uma_mtx); msleep(zone, zone->uz_lock, PVM, "zonedrain", 1); mtx_lock(&uma_mtx); } zone->uz_flags |= UMA_ZFLAG_DRAINING; bucket_cache_drain(zone); ZONE_UNLOCK(zone); /* * The DRAINING flag protects us from being freed while * we're running. Normally the uma_mtx would protect us but we * must be able to release and acquire the right lock for each keg. */ zone_foreach_keg(zone, &keg_drain); ZONE_LOCK(zone); zone->uz_flags &= ~UMA_ZFLAG_DRAINING; wakeup(zone); out: ZONE_UNLOCK(zone); } void zone_drain(uma_zone_t zone) { zone_drain_wait(zone, M_NOWAIT); } /* * Allocate a new slab for a keg. This does not insert the slab onto a list. * * Arguments: * wait Shall we wait? * * Returns: * The slab that was allocated or NULL if there is no memory and the * caller specified M_NOWAIT. */ static uma_slab_t keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int wait) { uma_slabrefcnt_t slabref; uma_alloc allocf; uma_slab_t slab; u_int8_t *mem; u_int8_t flags; int i; mtx_assert(&keg->uk_lock, MA_OWNED); slab = NULL; #ifdef UMA_DEBUG printf("slab_zalloc: Allocating a new slab for %s\n", keg->uk_name); #endif allocf = keg->uk_allocf; KEG_UNLOCK(keg); if (keg->uk_flags & UMA_ZONE_OFFPAGE) { slab = zone_alloc_item(keg->uk_slabzone, NULL, wait); if (slab == NULL) { KEG_LOCK(keg); return NULL; } } /* * This reproduces the old vm_zone behavior of zero filling pages the * first time they are added to a zone. * * Malloced items are zeroed in uma_zalloc. */ if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0) wait |= M_ZERO; else wait &= ~M_ZERO; /* zone is passed for legacy reasons. */ mem = allocf(zone, keg->uk_ppera * UMA_SLAB_SIZE, &flags, wait); if (mem == NULL) { if (keg->uk_flags & UMA_ZONE_OFFPAGE) zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE); KEG_LOCK(keg); return (NULL); } /* Point the slab into the allocated memory */ if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) slab = (uma_slab_t )(mem + keg->uk_pgoff); if (keg->uk_flags & UMA_ZONE_VTOSLAB) for (i = 0; i < keg->uk_ppera; i++) vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab); slab->us_keg = keg; slab->us_data = mem; slab->us_freecount = keg->uk_ipers; slab->us_firstfree = 0; slab->us_flags = flags; if (keg->uk_flags & UMA_ZONE_REFCNT) { slabref = (uma_slabrefcnt_t)slab; for (i = 0; i < keg->uk_ipers; i++) { slabref->us_freelist[i].us_refcnt = 0; slabref->us_freelist[i].us_item = i+1; } } else { for (i = 0; i < keg->uk_ipers; i++) slab->us_freelist[i].us_item = i+1; } if (keg->uk_init != NULL) { for (i = 0; i < keg->uk_ipers; i++) if (keg->uk_init(slab->us_data + (keg->uk_rsize * i), keg->uk_size, wait) != 0) break; if (i != keg->uk_ipers) { if (keg->uk_fini != NULL) { for (i--; i > -1; i--) keg->uk_fini(slab->us_data + (keg->uk_rsize * i), keg->uk_size); } if (keg->uk_flags & UMA_ZONE_VTOSLAB) { vm_object_t obj; if (flags & UMA_SLAB_KMEM) obj = kmem_object; else if (flags & UMA_SLAB_KERNEL) obj = kernel_object; else obj = NULL; for (i = 0; i < keg->uk_ppera; i++) vsetobj((vm_offset_t)mem + (i * PAGE_SIZE), obj); } if (keg->uk_flags & UMA_ZONE_OFFPAGE) zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE); keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera, flags); KEG_LOCK(keg); return (NULL); } } KEG_LOCK(keg); if (keg->uk_flags & UMA_ZONE_HASH) UMA_HASH_INSERT(&keg->uk_hash, slab, mem); keg->uk_pages += keg->uk_ppera; keg->uk_free += keg->uk_ipers; return (slab); } /* * This function is intended to be used early on in place of page_alloc() so * that we may use the boot time page cache to satisfy allocations before * the VM is ready. */ static void * startup_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait) { uma_keg_t keg; uma_slab_t tmps; keg = zone_first_keg(zone); /* * Check our small startup cache to see if it has pages remaining. */ mtx_lock(&uma_boot_pages_mtx); if ((tmps = LIST_FIRST(&uma_boot_pages)) != NULL) { LIST_REMOVE(tmps, us_link); mtx_unlock(&uma_boot_pages_mtx); *pflag = tmps->us_flags; return (tmps->us_data); } mtx_unlock(&uma_boot_pages_mtx); if (booted == 0) panic("UMA: Increase vm.boot_pages"); /* * Now that we've booted reset these users to their real allocator. */ #ifdef UMA_MD_SMALL_ALLOC keg->uk_allocf = uma_small_alloc; #else keg->uk_allocf = page_alloc; #endif return keg->uk_allocf(zone, bytes, pflag, wait); } /* * Allocates a number of pages from the system * * Arguments: * bytes The number of bytes requested * wait Shall we wait? * * Returns: * A pointer to the alloced memory or possibly * NULL if M_NOWAIT is set. */ static void * page_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait) { void *p; /* Returned page */ *pflag = UMA_SLAB_KMEM; p = (void *) kmem_malloc(kmem_map, bytes, wait); return (p); } /* * Allocates a number of pages from within an object * * Arguments: * bytes The number of bytes requested * wait Shall we wait? * * Returns: * A pointer to the alloced memory or possibly * NULL if M_NOWAIT is set. */ static void * obj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait) { vm_object_t object; vm_offset_t retkva, zkva; vm_page_t p; int pages, startpages; uma_keg_t keg; keg = zone_first_keg(zone); object = keg->uk_obj; retkva = 0; /* * This looks a little weird since we're getting one page at a time. */ VM_OBJECT_LOCK(object); p = TAILQ_LAST(&object->memq, pglist); pages = p != NULL ? p->pindex + 1 : 0; startpages = pages; zkva = keg->uk_kva + pages * PAGE_SIZE; for (; bytes > 0; bytes -= PAGE_SIZE) { p = vm_page_alloc(object, pages, VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED); if (p == NULL) { if (pages != startpages) pmap_qremove(retkva, pages - startpages); while (pages != startpages) { pages--; p = TAILQ_LAST(&object->memq, pglist); vm_page_unwire(p, 0); vm_page_free(p); } retkva = 0; goto done; } pmap_qenter(zkva, &p, 1); if (retkva == 0) retkva = zkva; zkva += PAGE_SIZE; pages += 1; } done: VM_OBJECT_UNLOCK(object); *flags = UMA_SLAB_PRIV; return ((void *)retkva); } /* * Frees a number of pages to the system * * Arguments: * mem A pointer to the memory to be freed * size The size of the memory being freed * flags The original p->us_flags field * * Returns: * Nothing */ static void page_free(void *mem, int size, u_int8_t flags) { vm_map_t map; if (flags & UMA_SLAB_KMEM) map = kmem_map; else if (flags & UMA_SLAB_KERNEL) map = kernel_map; else panic("UMA: page_free used with invalid flags %d", flags); kmem_free(map, (vm_offset_t)mem, size); } /* * Zero fill initializer * * Arguments/Returns follow uma_init specifications */ static int zero_init(void *mem, int size, int flags) { bzero(mem, size); return (0); } /* * Finish creating a small uma keg. This calculates ipers, and the keg size. * * Arguments * keg The zone we should initialize * * Returns * Nothing */ static void keg_small_init(uma_keg_t keg) { u_int rsize; u_int memused; u_int wastedspace; u_int shsize; KASSERT(keg != NULL, ("Keg is null in keg_small_init")); rsize = keg->uk_size; if (rsize < UMA_SMALLEST_UNIT) rsize = UMA_SMALLEST_UNIT; if (rsize & keg->uk_align) rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1); keg->uk_rsize = rsize; keg->uk_ppera = 1; if (keg->uk_flags & UMA_ZONE_REFCNT) { rsize += UMA_FRITMREF_SZ; /* linkage & refcnt */ shsize = sizeof(struct uma_slab_refcnt); } else { rsize += UMA_FRITM_SZ; /* Account for linkage */ shsize = sizeof(struct uma_slab); } keg->uk_ipers = (UMA_SLAB_SIZE - shsize) / rsize; KASSERT(keg->uk_ipers != 0, ("keg_small_init: ipers is 0")); memused = keg->uk_ipers * rsize + shsize; wastedspace = UMA_SLAB_SIZE - memused; /* * We can't do OFFPAGE if we're internal or if we've been * asked to not go to the VM for buckets. If we do this we * may end up going to the VM (kmem_map) for slabs which we * do not want to do if we're UMA_ZFLAG_CACHEONLY as a * result of UMA_ZONE_VM, which clearly forbids it. */ if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) || (keg->uk_flags & UMA_ZFLAG_CACHEONLY)) return; if ((wastedspace >= UMA_MAX_WASTE) && (keg->uk_ipers < (UMA_SLAB_SIZE / keg->uk_rsize))) { keg->uk_ipers = UMA_SLAB_SIZE / keg->uk_rsize; KASSERT(keg->uk_ipers <= 255, ("keg_small_init: keg->uk_ipers too high!")); #ifdef UMA_DEBUG printf("UMA decided we need offpage slab headers for " "keg: %s, calculated wastedspace = %d, " "maximum wasted space allowed = %d, " "calculated ipers = %d, " "new wasted space = %d\n", keg->uk_name, wastedspace, UMA_MAX_WASTE, keg->uk_ipers, UMA_SLAB_SIZE - keg->uk_ipers * keg->uk_rsize); #endif keg->uk_flags |= UMA_ZONE_OFFPAGE; if ((keg->uk_flags & UMA_ZONE_VTOSLAB) == 0) keg->uk_flags |= UMA_ZONE_HASH; } } /* * Finish creating a large (> UMA_SLAB_SIZE) uma kegs. Just give in and do * OFFPAGE for now. When I can allow for more dynamic slab sizes this will be * more complicated. * * Arguments * keg The keg we should initialize * * Returns * Nothing */ static void keg_large_init(uma_keg_t keg) { int pages; KASSERT(keg != NULL, ("Keg is null in keg_large_init")); KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0, ("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg")); pages = keg->uk_size / UMA_SLAB_SIZE; /* Account for remainder */ if ((pages * UMA_SLAB_SIZE) < keg->uk_size) pages++; keg->uk_ppera = pages; keg->uk_ipers = 1; keg->uk_flags |= UMA_ZONE_OFFPAGE; if ((keg->uk_flags & UMA_ZONE_VTOSLAB) == 0) keg->uk_flags |= UMA_ZONE_HASH; keg->uk_rsize = keg->uk_size; } static void keg_cachespread_init(uma_keg_t keg) { int alignsize; int trailer; int pages; int rsize; alignsize = keg->uk_align + 1; rsize = keg->uk_size; /* * We want one item to start on every align boundary in a page. To * do this we will span pages. We will also extend the item by the * size of align if it is an even multiple of align. Otherwise, it * would fall on the same boundary every time. */ if (rsize & keg->uk_align) rsize = (rsize & ~keg->uk_align) + alignsize; if ((rsize & alignsize) == 0) rsize += alignsize; trailer = rsize - keg->uk_size; pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE; pages = MIN(pages, (128 * 1024) / PAGE_SIZE); keg->uk_rsize = rsize; keg->uk_ppera = pages; keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize; keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB; KASSERT(keg->uk_ipers <= uma_max_ipers, ("keg_small_init: keg->uk_ipers too high(%d) increase max_ipers", keg->uk_ipers)); } /* * Keg header ctor. This initializes all fields, locks, etc. And inserts * the keg onto the global keg list. * * Arguments/Returns follow uma_ctor specifications * udata Actually uma_kctor_args */ static int keg_ctor(void *mem, int size, void *udata, int flags) { struct uma_kctor_args *arg = udata; uma_keg_t keg = mem; uma_zone_t zone; bzero(keg, size); keg->uk_size = arg->size; keg->uk_init = arg->uminit; keg->uk_fini = arg->fini; keg->uk_align = arg->align; keg->uk_free = 0; keg->uk_pages = 0; keg->uk_flags = arg->flags; keg->uk_allocf = page_alloc; keg->uk_freef = page_free; keg->uk_recurse = 0; keg->uk_slabzone = NULL; /* * The master zone is passed to us at keg-creation time. */ zone = arg->zone; keg->uk_name = zone->uz_name; if (arg->flags & UMA_ZONE_VM) keg->uk_flags |= UMA_ZFLAG_CACHEONLY; if (arg->flags & UMA_ZONE_ZINIT) keg->uk_init = zero_init; if (arg->flags & UMA_ZONE_REFCNT || arg->flags & UMA_ZONE_MALLOC) keg->uk_flags |= UMA_ZONE_VTOSLAB; /* * The +UMA_FRITM_SZ added to uk_size is to account for the * linkage that is added to the size in keg_small_init(). If * we don't account for this here then we may end up in * keg_small_init() with a calculated 'ipers' of 0. */ if (keg->uk_flags & UMA_ZONE_REFCNT) { if (keg->uk_flags & UMA_ZONE_CACHESPREAD) keg_cachespread_init(keg); else if ((keg->uk_size+UMA_FRITMREF_SZ) > (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt))) keg_large_init(keg); else keg_small_init(keg); } else { if (keg->uk_flags & UMA_ZONE_CACHESPREAD) keg_cachespread_init(keg); else if ((keg->uk_size+UMA_FRITM_SZ) > (UMA_SLAB_SIZE - sizeof(struct uma_slab))) keg_large_init(keg); else keg_small_init(keg); } if (keg->uk_flags & UMA_ZONE_OFFPAGE) { if (keg->uk_flags & UMA_ZONE_REFCNT) keg->uk_slabzone = slabrefzone; else keg->uk_slabzone = slabzone; } /* * If we haven't booted yet we need allocations to go through the * startup cache until the vm is ready. */ if (keg->uk_ppera == 1) { #ifdef UMA_MD_SMALL_ALLOC keg->uk_allocf = uma_small_alloc; keg->uk_freef = uma_small_free; #endif if (booted == 0) keg->uk_allocf = startup_alloc; } /* * Initialize keg's lock (shared among zones). */ if (arg->flags & UMA_ZONE_MTXCLASS) KEG_LOCK_INIT(keg, 1); else KEG_LOCK_INIT(keg, 0); /* * If we're putting the slab header in the actual page we need to * figure out where in each page it goes. This calculates a right * justified offset into the memory on an ALIGN_PTR boundary. */ if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) { u_int totsize; /* Size of the slab struct and free list */ if (keg->uk_flags & UMA_ZONE_REFCNT) totsize = sizeof(struct uma_slab_refcnt) + keg->uk_ipers * UMA_FRITMREF_SZ; else totsize = sizeof(struct uma_slab) + keg->uk_ipers * UMA_FRITM_SZ; if (totsize & UMA_ALIGN_PTR) totsize = (totsize & ~UMA_ALIGN_PTR) + (UMA_ALIGN_PTR + 1); keg->uk_pgoff = UMA_SLAB_SIZE - totsize; if (keg->uk_flags & UMA_ZONE_REFCNT) totsize = keg->uk_pgoff + sizeof(struct uma_slab_refcnt) + keg->uk_ipers * UMA_FRITMREF_SZ; else totsize = keg->uk_pgoff + sizeof(struct uma_slab) + keg->uk_ipers * UMA_FRITM_SZ; /* * The only way the following is possible is if with our * UMA_ALIGN_PTR adjustments we are now bigger than * UMA_SLAB_SIZE. I haven't checked whether this is * mathematically possible for all cases, so we make * sure here anyway. */ if (totsize > UMA_SLAB_SIZE) { printf("zone %s ipers %d rsize %d size %d\n", zone->uz_name, keg->uk_ipers, keg->uk_rsize, keg->uk_size); panic("UMA slab won't fit."); } } if (keg->uk_flags & UMA_ZONE_HASH) hash_alloc(&keg->uk_hash); #ifdef UMA_DEBUG printf("UMA: %s(%p) size %d(%d) flags %d ipers %d ppera %d out %d free %d\n", zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags, keg->uk_ipers, keg->uk_ppera, (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free); #endif LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link); mtx_lock(&uma_mtx); LIST_INSERT_HEAD(&uma_kegs, keg, uk_link); mtx_unlock(&uma_mtx); return (0); } /* * Zone header ctor. This initializes all fields, locks, etc. * * Arguments/Returns follow uma_ctor specifications * udata Actually uma_zctor_args */ static int zone_ctor(void *mem, int size, void *udata, int flags) { struct uma_zctor_args *arg = udata; uma_zone_t zone = mem; uma_zone_t z; uma_keg_t keg; bzero(zone, size); zone->uz_name = arg->name; zone->uz_ctor = arg->ctor; zone->uz_dtor = arg->dtor; zone->uz_slab = zone_fetch_slab; zone->uz_init = NULL; zone->uz_fini = NULL; zone->uz_allocs = 0; zone->uz_frees = 0; zone->uz_fails = 0; zone->uz_fills = zone->uz_count = 0; zone->uz_flags = 0; keg = arg->keg; if (arg->flags & UMA_ZONE_SECONDARY) { KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg")); zone->uz_init = arg->uminit; zone->uz_fini = arg->fini; zone->uz_lock = &keg->uk_lock; zone->uz_flags |= UMA_ZONE_SECONDARY; mtx_lock(&uma_mtx); ZONE_LOCK(zone); LIST_FOREACH(z, &keg->uk_zones, uz_link) { if (LIST_NEXT(z, uz_link) == NULL) { LIST_INSERT_AFTER(z, zone, uz_link); break; } } ZONE_UNLOCK(zone); mtx_unlock(&uma_mtx); } else if (keg == NULL) { if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini, arg->align, arg->flags)) == NULL) return (ENOMEM); } else { struct uma_kctor_args karg; int error; /* We should only be here from uma_startup() */ karg.size = arg->size; karg.uminit = arg->uminit; karg.fini = arg->fini; karg.align = arg->align; karg.flags = arg->flags; karg.zone = zone; error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg, flags); if (error) return (error); } /* * Link in the first keg. */ zone->uz_klink.kl_keg = keg; LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link); zone->uz_lock = &keg->uk_lock; zone->uz_size = keg->uk_size; zone->uz_flags |= (keg->uk_flags & (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT)); /* * Some internal zones don't have room allocated for the per cpu * caches. If we're internal, bail out here. */ if (keg->uk_flags & UMA_ZFLAG_INTERNAL) { KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0, ("Secondary zone requested UMA_ZFLAG_INTERNAL")); return (0); } if (keg->uk_flags & UMA_ZONE_MAXBUCKET) zone->uz_count = BUCKET_MAX; else if (keg->uk_ipers <= BUCKET_MAX) zone->uz_count = keg->uk_ipers; else zone->uz_count = BUCKET_MAX; return (0); } /* * Keg header dtor. This frees all data, destroys locks, frees the hash * table and removes the keg from the global list. * * Arguments/Returns follow uma_dtor specifications * udata unused */ static void keg_dtor(void *arg, int size, void *udata) { uma_keg_t keg; keg = (uma_keg_t)arg; KEG_LOCK(keg); if (keg->uk_free != 0) { printf("Freed UMA keg was not empty (%d items). " " Lost %d pages of memory.\n", keg->uk_free, keg->uk_pages); } KEG_UNLOCK(keg); hash_free(&keg->uk_hash); KEG_LOCK_FINI(keg); } /* * Zone header dtor. * * Arguments/Returns follow uma_dtor specifications * udata unused */ static void zone_dtor(void *arg, int size, void *udata) { uma_klink_t klink; uma_zone_t zone; uma_keg_t keg; zone = (uma_zone_t)arg; keg = zone_first_keg(zone); if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL)) cache_drain(zone); mtx_lock(&uma_mtx); LIST_REMOVE(zone, uz_link); mtx_unlock(&uma_mtx); /* * XXX there are some races here where * the zone can be drained but zone lock * released and then refilled before we * remove it... we dont care for now */ zone_drain_wait(zone, M_WAITOK); /* * Unlink all of our kegs. */ while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) { klink->kl_keg = NULL; LIST_REMOVE(klink, kl_link); if (klink == &zone->uz_klink) continue; free(klink, M_TEMP); } /* * We only destroy kegs from non secondary zones. */ if ((zone->uz_flags & UMA_ZONE_SECONDARY) == 0) { mtx_lock(&uma_mtx); LIST_REMOVE(keg, uk_link); mtx_unlock(&uma_mtx); zone_free_item(kegs, keg, NULL, SKIP_NONE, ZFREE_STATFREE); } } /* * Traverses every zone in the system and calls a callback * * Arguments: * zfunc A pointer to a function which accepts a zone * as an argument. * * Returns: * Nothing */ static void zone_foreach(void (*zfunc)(uma_zone_t)) { uma_keg_t keg; uma_zone_t zone; mtx_lock(&uma_mtx); LIST_FOREACH(keg, &uma_kegs, uk_link) { LIST_FOREACH(zone, &keg->uk_zones, uz_link) zfunc(zone); } mtx_unlock(&uma_mtx); } /* Public functions */ /* See uma.h */ void uma_startup(void *bootmem, int boot_pages) { struct uma_zctor_args args; uma_slab_t slab; u_int slabsize; u_int objsize, totsize, wsize; int i; #ifdef UMA_DEBUG printf("Creating uma keg headers zone and keg.\n"); #endif mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF); /* * Figure out the maximum number of items-per-slab we'll have if * we're using the OFFPAGE slab header to track free items, given * all possible object sizes and the maximum desired wastage * (UMA_MAX_WASTE). * * We iterate until we find an object size for * which the calculated wastage in keg_small_init() will be * enough to warrant OFFPAGE. Since wastedspace versus objsize * is an overall increasing see-saw function, we find the smallest * objsize such that the wastage is always acceptable for objects * with that objsize or smaller. Since a smaller objsize always * generates a larger possible uma_max_ipers, we use this computed * objsize to calculate the largest ipers possible. Since the * ipers calculated for OFFPAGE slab headers is always larger than * the ipers initially calculated in keg_small_init(), we use * the former's equation (UMA_SLAB_SIZE / keg->uk_rsize) to * obtain the maximum ipers possible for offpage slab headers. * * It should be noted that ipers versus objsize is an inversly * proportional function which drops off rather quickly so as * long as our UMA_MAX_WASTE is such that the objsize we calculate * falls into the portion of the inverse relation AFTER the steep * falloff, then uma_max_ipers shouldn't be too high (~10 on i386). * * Note that we have 8-bits (1 byte) to use as a freelist index * inside the actual slab header itself and this is enough to * accomodate us. In the worst case, a UMA_SMALLEST_UNIT sized * object with offpage slab header would have ipers = * UMA_SLAB_SIZE / UMA_SMALLEST_UNIT (currently = 256), which is * 1 greater than what our byte-integer freelist index can * accomodate, but we know that this situation never occurs as * for UMA_SMALLEST_UNIT-sized objects, we will never calculate * that we need to go to offpage slab headers. Or, if we do, * then we trap that condition below and panic in the INVARIANTS case. */ wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab) - UMA_MAX_WASTE; totsize = wsize; objsize = UMA_SMALLEST_UNIT; while (totsize >= wsize) { totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) / (objsize + UMA_FRITM_SZ); totsize *= (UMA_FRITM_SZ + objsize); objsize++; } if (objsize > UMA_SMALLEST_UNIT) objsize--; uma_max_ipers = MAX(UMA_SLAB_SIZE / objsize, 64); wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) - UMA_MAX_WASTE; totsize = wsize; objsize = UMA_SMALLEST_UNIT; while (totsize >= wsize) { totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)) / (objsize + UMA_FRITMREF_SZ); totsize *= (UMA_FRITMREF_SZ + objsize); objsize++; } if (objsize > UMA_SMALLEST_UNIT) objsize--; uma_max_ipers_ref = MAX(UMA_SLAB_SIZE / objsize, 64); KASSERT((uma_max_ipers_ref <= 255) && (uma_max_ipers <= 255), ("uma_startup: calculated uma_max_ipers values too large!")); #ifdef UMA_DEBUG printf("Calculated uma_max_ipers (for OFFPAGE) is %d\n", uma_max_ipers); printf("Calculated uma_max_ipers_slab (for OFFPAGE) is %d\n", uma_max_ipers_ref); #endif /* "manually" create the initial zone */ args.name = "UMA Kegs"; args.size = sizeof(struct uma_keg); args.ctor = keg_ctor; args.dtor = keg_dtor; args.uminit = zero_init; args.fini = NULL; args.keg = &masterkeg; args.align = 32 - 1; args.flags = UMA_ZFLAG_INTERNAL; /* The initial zone has no Per cpu queues so it's smaller */ zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK); #ifdef UMA_DEBUG printf("Filling boot free list.\n"); #endif for (i = 0; i < boot_pages; i++) { slab = (uma_slab_t)((u_int8_t *)bootmem + (i * UMA_SLAB_SIZE)); slab->us_data = (u_int8_t *)slab; slab->us_flags = UMA_SLAB_BOOT; LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link); } mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF); #ifdef UMA_DEBUG printf("Creating uma zone headers zone and keg.\n"); #endif args.name = "UMA Zones"; args.size = sizeof(struct uma_zone) + (sizeof(struct uma_cache) * (mp_maxid + 1)); args.ctor = zone_ctor; args.dtor = zone_dtor; args.uminit = zero_init; args.fini = NULL; args.keg = NULL; args.align = 32 - 1; args.flags = UMA_ZFLAG_INTERNAL; /* The initial zone has no Per cpu queues so it's smaller */ zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK); #ifdef UMA_DEBUG printf("Initializing pcpu cache locks.\n"); #endif #ifdef UMA_DEBUG printf("Creating slab and hash zones.\n"); #endif /* * This is the max number of free list items we'll have with * offpage slabs. */ slabsize = uma_max_ipers * UMA_FRITM_SZ; slabsize += sizeof(struct uma_slab); /* Now make a zone for slab headers */ slabzone = uma_zcreate("UMA Slabs", slabsize, NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL); /* * We also create a zone for the bigger slabs with reference * counts in them, to accomodate UMA_ZONE_REFCNT zones. */ slabsize = uma_max_ipers_ref * UMA_FRITMREF_SZ; slabsize += sizeof(struct uma_slab_refcnt); slabrefzone = uma_zcreate("UMA RCntSlabs", slabsize, NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL); hashzone = uma_zcreate("UMA Hash", sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT, NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL); bucket_init(); #if defined(UMA_MD_SMALL_ALLOC) && !defined(UMA_MD_SMALL_ALLOC_NEEDS_VM) booted = 1; #endif #ifdef UMA_DEBUG printf("UMA startup complete.\n"); #endif } /* see uma.h */ void uma_startup2(void) { booted = 1; bucket_enable(); #ifdef UMA_DEBUG printf("UMA startup2 complete.\n"); #endif } /* * Initialize our callout handle * */ static void uma_startup3(void) { #ifdef UMA_DEBUG printf("Starting callout.\n"); #endif callout_init(&uma_callout, CALLOUT_MPSAFE); callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL); #ifdef UMA_DEBUG printf("UMA startup3 complete.\n"); #endif } static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini, int align, u_int32_t flags) { struct uma_kctor_args args; args.size = size; args.uminit = uminit; args.fini = fini; args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align; args.flags = flags; args.zone = zone; return (zone_alloc_item(kegs, &args, M_WAITOK)); } /* See uma.h */ void uma_set_align(int align) { if (align != UMA_ALIGN_CACHE) uma_align_cache = align; } /* See uma.h */ uma_zone_t uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor, uma_init uminit, uma_fini fini, int align, u_int32_t flags) { struct uma_zctor_args args; /* This stuff is essential for the zone ctor */ args.name = name; args.size = size; args.ctor = ctor; args.dtor = dtor; args.uminit = uminit; args.fini = fini; args.align = align; args.flags = flags; args.keg = NULL; return (zone_alloc_item(zones, &args, M_WAITOK)); } /* See uma.h */ uma_zone_t uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor, uma_init zinit, uma_fini zfini, uma_zone_t master) { struct uma_zctor_args args; uma_keg_t keg; keg = zone_first_keg(master); args.name = name; args.size = keg->uk_size; args.ctor = ctor; args.dtor = dtor; args.uminit = zinit; args.fini = zfini; args.align = keg->uk_align; args.flags = keg->uk_flags | UMA_ZONE_SECONDARY; args.keg = keg; /* XXX Attaches only one keg of potentially many. */ return (zone_alloc_item(zones, &args, M_WAITOK)); } static void zone_lock_pair(uma_zone_t a, uma_zone_t b) { if (a < b) { ZONE_LOCK(a); mtx_lock_flags(b->uz_lock, MTX_DUPOK); } else { ZONE_LOCK(b); mtx_lock_flags(a->uz_lock, MTX_DUPOK); } } static void zone_unlock_pair(uma_zone_t a, uma_zone_t b) { ZONE_UNLOCK(a); ZONE_UNLOCK(b); } int uma_zsecond_add(uma_zone_t zone, uma_zone_t master) { uma_klink_t klink; uma_klink_t kl; int error; error = 0; klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO); zone_lock_pair(zone, master); /* * zone must use vtoslab() to resolve objects and must already be * a secondary. */ if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) { error = EINVAL; goto out; } /* * The new master must also use vtoslab(). */ if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) { error = EINVAL; goto out; } /* * Both must either be refcnt, or not be refcnt. */ if ((zone->uz_flags & UMA_ZONE_REFCNT) != (master->uz_flags & UMA_ZONE_REFCNT)) { error = EINVAL; goto out; } /* * The underlying object must be the same size. rsize * may be different. */ if (master->uz_size != zone->uz_size) { error = E2BIG; goto out; } /* * Put it at the end of the list. */ klink->kl_keg = zone_first_keg(master); LIST_FOREACH(kl, &zone->uz_kegs, kl_link) { if (LIST_NEXT(kl, kl_link) == NULL) { LIST_INSERT_AFTER(kl, klink, kl_link); break; } } klink = NULL; zone->uz_flags |= UMA_ZFLAG_MULTI; zone->uz_slab = zone_fetch_slab_multi; out: zone_unlock_pair(zone, master); if (klink != NULL) free(klink, M_TEMP); return (error); } /* See uma.h */ void uma_zdestroy(uma_zone_t zone) { zone_free_item(zones, zone, NULL, SKIP_NONE, ZFREE_STATFREE); } /* See uma.h */ void * uma_zalloc_arg(uma_zone_t zone, void *udata, int flags) { void *item; uma_cache_t cache; uma_bucket_t bucket; int cpu; /* This is the fast path allocation */ #ifdef UMA_DEBUG_ALLOC_1 printf("Allocating one item from %s(%p)\n", zone->uz_name, zone); #endif CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread, zone->uz_name, flags); if (flags & M_WAITOK) { WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "uma_zalloc_arg: zone \"%s\"", zone->uz_name); } /* * If possible, allocate from the per-CPU cache. There are two * requirements for safe access to the per-CPU cache: (1) the thread * accessing the cache must not be preempted or yield during access, * and (2) the thread must not migrate CPUs without switching which * cache it accesses. We rely on a critical section to prevent * preemption and migration. We release the critical section in * order to acquire the zone mutex if we are unable to allocate from * the current cache; when we re-acquire the critical section, we * must detect and handle migration if it has occurred. */ zalloc_restart: critical_enter(); cpu = curcpu; cache = &zone->uz_cpu[cpu]; zalloc_start: bucket = cache->uc_allocbucket; if (bucket) { if (bucket->ub_cnt > 0) { bucket->ub_cnt--; item = bucket->ub_bucket[bucket->ub_cnt]; #ifdef INVARIANTS bucket->ub_bucket[bucket->ub_cnt] = NULL; #endif KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled.")); cache->uc_allocs++; critical_exit(); #ifdef INVARIANTS ZONE_LOCK(zone); uma_dbg_alloc(zone, NULL, item); ZONE_UNLOCK(zone); #endif if (zone->uz_ctor != NULL) { if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) { zone_free_item(zone, item, udata, SKIP_DTOR, ZFREE_STATFAIL | ZFREE_STATFREE); return (NULL); } } if (flags & M_ZERO) bzero(item, zone->uz_size); return (item); } else if (cache->uc_freebucket) { /* * We have run out of items in our allocbucket. * See if we can switch with our free bucket. */ if (cache->uc_freebucket->ub_cnt > 0) { #ifdef UMA_DEBUG_ALLOC printf("uma_zalloc: Swapping empty with" " alloc.\n"); #endif bucket = cache->uc_freebucket; cache->uc_freebucket = cache->uc_allocbucket; cache->uc_allocbucket = bucket; goto zalloc_start; } } } /* * Attempt to retrieve the item from the per-CPU cache has failed, so * we must go back to the zone. This requires the zone lock, so we * must drop the critical section, then re-acquire it when we go back * to the cache. Since the critical section is released, we may be * preempted or migrate. As such, make sure not to maintain any * thread-local state specific to the cache from prior to releasing * the critical section. */ critical_exit(); ZONE_LOCK(zone); critical_enter(); cpu = curcpu; cache = &zone->uz_cpu[cpu]; bucket = cache->uc_allocbucket; if (bucket != NULL) { if (bucket->ub_cnt > 0) { ZONE_UNLOCK(zone); goto zalloc_start; } bucket = cache->uc_freebucket; if (bucket != NULL && bucket->ub_cnt > 0) { ZONE_UNLOCK(zone); goto zalloc_start; } } /* Since we have locked the zone we may as well send back our stats */ zone->uz_allocs += cache->uc_allocs; cache->uc_allocs = 0; zone->uz_frees += cache->uc_frees; cache->uc_frees = 0; /* Our old one is now a free bucket */ if (cache->uc_allocbucket) { KASSERT(cache->uc_allocbucket->ub_cnt == 0, ("uma_zalloc_arg: Freeing a non free bucket.")); LIST_INSERT_HEAD(&zone->uz_free_bucket, cache->uc_allocbucket, ub_link); cache->uc_allocbucket = NULL; } /* Check the free list for a new alloc bucket */ if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) { KASSERT(bucket->ub_cnt != 0, ("uma_zalloc_arg: Returning an empty bucket.")); LIST_REMOVE(bucket, ub_link); cache->uc_allocbucket = bucket; ZONE_UNLOCK(zone); goto zalloc_start; } /* We are no longer associated with this CPU. */ critical_exit(); /* Bump up our uz_count so we get here less */ if (zone->uz_count < BUCKET_MAX) zone->uz_count++; /* * Now lets just fill a bucket and put it on the free list. If that * works we'll restart the allocation from the begining. */ if (zone_alloc_bucket(zone, flags)) { ZONE_UNLOCK(zone); goto zalloc_restart; } ZONE_UNLOCK(zone); /* * We may not be able to get a bucket so return an actual item. */ #ifdef UMA_DEBUG printf("uma_zalloc_arg: Bucketzone returned NULL\n"); #endif item = zone_alloc_item(zone, udata, flags); return (item); } static uma_slab_t keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int flags) { uma_slab_t slab; mtx_assert(&keg->uk_lock, MA_OWNED); slab = NULL; for (;;) { /* * Find a slab with some space. Prefer slabs that are partially * used over those that are totally full. This helps to reduce * fragmentation. */ if (keg->uk_free != 0) { if (!LIST_EMPTY(&keg->uk_part_slab)) { slab = LIST_FIRST(&keg->uk_part_slab); } else { slab = LIST_FIRST(&keg->uk_free_slab); LIST_REMOVE(slab, us_link); LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link); } MPASS(slab->us_keg == keg); return (slab); } /* * M_NOVM means don't ask at all! */ if (flags & M_NOVM) break; if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) { keg->uk_flags |= UMA_ZFLAG_FULL; /* * If this is not a multi-zone, set the FULL bit. * Otherwise slab_multi() takes care of it. */ if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) zone->uz_flags |= UMA_ZFLAG_FULL; if (flags & M_NOWAIT) break; msleep(keg, &keg->uk_lock, PVM, "keglimit", 0); continue; } keg->uk_recurse++; slab = keg_alloc_slab(keg, zone, flags); keg->uk_recurse--; /* * If we got a slab here it's safe to mark it partially used * and return. We assume that the caller is going to remove * at least one item. */ if (slab) { MPASS(slab->us_keg == keg); LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link); return (slab); } /* * We might not have been able to get a slab but another cpu * could have while we were unlocked. Check again before we * fail. */ flags |= M_NOVM; } return (slab); } static inline void zone_relock(uma_zone_t zone, uma_keg_t keg) { if (zone->uz_lock != &keg->uk_lock) { KEG_UNLOCK(keg); ZONE_LOCK(zone); } } static inline void keg_relock(uma_keg_t keg, uma_zone_t zone) { if (zone->uz_lock != &keg->uk_lock) { ZONE_UNLOCK(zone); KEG_LOCK(keg); } } static uma_slab_t zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int flags) { uma_slab_t slab; if (keg == NULL) keg = zone_first_keg(zone); /* * This is to prevent us from recursively trying to allocate * buckets. The problem is that if an allocation forces us to * grab a new bucket we will call page_alloc, which will go off * and cause the vm to allocate vm_map_entries. If we need new * buckets there too we will recurse in kmem_alloc and bad * things happen. So instead we return a NULL bucket, and make * the code that allocates buckets smart enough to deal with it */ if (keg->uk_flags & UMA_ZFLAG_BUCKET && keg->uk_recurse != 0) return (NULL); for (;;) { slab = keg_fetch_slab(keg, zone, flags); if (slab) return (slab); if (flags & (M_NOWAIT | M_NOVM)) break; } return (NULL); } /* * uma_zone_fetch_slab_multi: Fetches a slab from one available keg. Returns * with the keg locked. Caller must call zone_relock() afterwards if the * zone lock is required. On NULL the zone lock is held. * * The last pointer is used to seed the search. It is not required. */ static uma_slab_t zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int rflags) { uma_klink_t klink; uma_slab_t slab; uma_keg_t keg; int flags; int empty; int full; /* * Don't wait on the first pass. This will skip limit tests * as well. We don't want to block if we can find a provider * without blocking. */ flags = (rflags & ~M_WAITOK) | M_NOWAIT; /* * Use the last slab allocated as a hint for where to start * the search. */ if (last) { slab = keg_fetch_slab(last, zone, flags); if (slab) return (slab); zone_relock(zone, last); last = NULL; } /* * Loop until we have a slab incase of transient failures * while M_WAITOK is specified. I'm not sure this is 100% * required but we've done it for so long now. */ for (;;) { empty = 0; full = 0; /* * Search the available kegs for slabs. Be careful to hold the * correct lock while calling into the keg layer. */ LIST_FOREACH(klink, &zone->uz_kegs, kl_link) { keg = klink->kl_keg; keg_relock(keg, zone); if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) { slab = keg_fetch_slab(keg, zone, flags); if (slab) return (slab); } if (keg->uk_flags & UMA_ZFLAG_FULL) full++; else empty++; zone_relock(zone, keg); } if (rflags & (M_NOWAIT | M_NOVM)) break; flags = rflags; /* * All kegs are full. XXX We can't atomically check all kegs * and sleep so just sleep for a short period and retry. */ if (full && !empty) { zone->uz_flags |= UMA_ZFLAG_FULL; msleep(zone, zone->uz_lock, PVM, "zonelimit", hz/100); zone->uz_flags &= ~UMA_ZFLAG_FULL; continue; } } return (NULL); } static void * slab_alloc_item(uma_zone_t zone, uma_slab_t slab) { uma_keg_t keg; uma_slabrefcnt_t slabref; void *item; u_int8_t freei; keg = slab->us_keg; mtx_assert(&keg->uk_lock, MA_OWNED); freei = slab->us_firstfree; if (keg->uk_flags & UMA_ZONE_REFCNT) { slabref = (uma_slabrefcnt_t)slab; slab->us_firstfree = slabref->us_freelist[freei].us_item; } else { slab->us_firstfree = slab->us_freelist[freei].us_item; } item = slab->us_data + (keg->uk_rsize * freei); slab->us_freecount--; keg->uk_free--; #ifdef INVARIANTS uma_dbg_alloc(zone, slab, item); #endif /* Move this slab to the full list */ if (slab->us_freecount == 0) { LIST_REMOVE(slab, us_link); LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link); } return (item); } static int zone_alloc_bucket(uma_zone_t zone, int flags) { uma_bucket_t bucket; uma_slab_t slab; uma_keg_t keg; int16_t saved; int max, origflags = flags; /* * Try this zone's free list first so we don't allocate extra buckets. */ if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) { KASSERT(bucket->ub_cnt == 0, ("zone_alloc_bucket: Bucket on free list is not empty.")); LIST_REMOVE(bucket, ub_link); } else { int bflags; bflags = (flags & ~M_ZERO); if (zone->uz_flags & UMA_ZFLAG_CACHEONLY) bflags |= M_NOVM; ZONE_UNLOCK(zone); bucket = bucket_alloc(zone->uz_count, bflags); ZONE_LOCK(zone); } if (bucket == NULL) { return (0); } #ifdef SMP /* * This code is here to limit the number of simultaneous bucket fills * for any given zone to the number of per cpu caches in this zone. This * is done so that we don't allocate more memory than we really need. */ if (zone->uz_fills >= mp_ncpus) goto done; #endif zone->uz_fills++; max = MIN(bucket->ub_entries, zone->uz_count); /* Try to keep the buckets totally full */ saved = bucket->ub_cnt; slab = NULL; keg = NULL; while (bucket->ub_cnt < max && (slab = zone->uz_slab(zone, keg, flags)) != NULL) { keg = slab->us_keg; while (slab->us_freecount && bucket->ub_cnt < max) { bucket->ub_bucket[bucket->ub_cnt++] = slab_alloc_item(zone, slab); } /* Don't block on the next fill */ flags |= M_NOWAIT; } if (slab) zone_relock(zone, keg); /* * We unlock here because we need to call the zone's init. * It should be safe to unlock because the slab dealt with * above is already on the appropriate list within the keg * and the bucket we filled is not yet on any list, so we * own it. */ if (zone->uz_init != NULL) { int i; ZONE_UNLOCK(zone); for (i = saved; i < bucket->ub_cnt; i++) if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size, origflags) != 0) break; /* * If we couldn't initialize the whole bucket, put the * rest back onto the freelist. */ if (i != bucket->ub_cnt) { int j; for (j = i; j < bucket->ub_cnt; j++) { zone_free_item(zone, bucket->ub_bucket[j], NULL, SKIP_FINI, 0); #ifdef INVARIANTS bucket->ub_bucket[j] = NULL; #endif } bucket->ub_cnt = i; } ZONE_LOCK(zone); } zone->uz_fills--; if (bucket->ub_cnt != 0) { LIST_INSERT_HEAD(&zone->uz_full_bucket, bucket, ub_link); return (1); } #ifdef SMP done: #endif bucket_free(bucket); return (0); } /* * Allocates an item for an internal zone * * Arguments * zone The zone to alloc for. * udata The data to be passed to the constructor. * flags M_WAITOK, M_NOWAIT, M_ZERO. * * Returns * NULL if there is no memory and M_NOWAIT is set * An item if successful */ static void * zone_alloc_item(uma_zone_t zone, void *udata, int flags) { uma_slab_t slab; void *item; item = NULL; #ifdef UMA_DEBUG_ALLOC printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone); #endif ZONE_LOCK(zone); slab = zone->uz_slab(zone, NULL, flags); if (slab == NULL) { zone->uz_fails++; ZONE_UNLOCK(zone); return (NULL); } item = slab_alloc_item(zone, slab); zone_relock(zone, slab->us_keg); zone->uz_allocs++; ZONE_UNLOCK(zone); /* * We have to call both the zone's init (not the keg's init) * and the zone's ctor. This is because the item is going from * a keg slab directly to the user, and the user is expecting it * to be both zone-init'd as well as zone-ctor'd. */ if (zone->uz_init != NULL) { if (zone->uz_init(item, zone->uz_size, flags) != 0) { zone_free_item(zone, item, udata, SKIP_FINI, ZFREE_STATFAIL | ZFREE_STATFREE); return (NULL); } } if (zone->uz_ctor != NULL) { if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) { zone_free_item(zone, item, udata, SKIP_DTOR, ZFREE_STATFAIL | ZFREE_STATFREE); return (NULL); } } if (flags & M_ZERO) bzero(item, zone->uz_size); return (item); } /* See uma.h */ void uma_zfree_arg(uma_zone_t zone, void *item, void *udata) { uma_cache_t cache; uma_bucket_t bucket; int bflags; int cpu; #ifdef UMA_DEBUG_ALLOC_1 printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone); #endif CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread, zone->uz_name); if (zone->uz_dtor) zone->uz_dtor(item, zone->uz_size, udata); #ifdef INVARIANTS ZONE_LOCK(zone); if (zone->uz_flags & UMA_ZONE_MALLOC) uma_dbg_free(zone, udata, item); else uma_dbg_free(zone, NULL, item); ZONE_UNLOCK(zone); #endif /* * The race here is acceptable. If we miss it we'll just have to wait * a little longer for the limits to be reset. */ if (zone->uz_flags & UMA_ZFLAG_FULL) goto zfree_internal; /* * If possible, free to the per-CPU cache. There are two * requirements for safe access to the per-CPU cache: (1) the thread * accessing the cache must not be preempted or yield during access, * and (2) the thread must not migrate CPUs without switching which * cache it accesses. We rely on a critical section to prevent * preemption and migration. We release the critical section in * order to acquire the zone mutex if we are unable to free to the * current cache; when we re-acquire the critical section, we must * detect and handle migration if it has occurred. */ zfree_restart: critical_enter(); cpu = curcpu; cache = &zone->uz_cpu[cpu]; zfree_start: bucket = cache->uc_freebucket; if (bucket) { /* * Do we have room in our bucket? It is OK for this uz count * check to be slightly out of sync. */ if (bucket->ub_cnt < bucket->ub_entries) { KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL, ("uma_zfree: Freeing to non free bucket index.")); bucket->ub_bucket[bucket->ub_cnt] = item; bucket->ub_cnt++; cache->uc_frees++; critical_exit(); return; } else if (cache->uc_allocbucket) { #ifdef UMA_DEBUG_ALLOC printf("uma_zfree: Swapping buckets.\n"); #endif /* * We have run out of space in our freebucket. * See if we can switch with our alloc bucket. */ if (cache->uc_allocbucket->ub_cnt < cache->uc_freebucket->ub_cnt) { bucket = cache->uc_freebucket; cache->uc_freebucket = cache->uc_allocbucket; cache->uc_allocbucket = bucket; goto zfree_start; } } } /* * We can get here for two reasons: * * 1) The buckets are NULL * 2) The alloc and free buckets are both somewhat full. * * We must go back the zone, which requires acquiring the zone lock, * which in turn means we must release and re-acquire the critical * section. Since the critical section is released, we may be * preempted or migrate. As such, make sure not to maintain any * thread-local state specific to the cache from prior to releasing * the critical section. */ critical_exit(); ZONE_LOCK(zone); critical_enter(); cpu = curcpu; cache = &zone->uz_cpu[cpu]; if (cache->uc_freebucket != NULL) { if (cache->uc_freebucket->ub_cnt < cache->uc_freebucket->ub_entries) { ZONE_UNLOCK(zone); goto zfree_start; } if (cache->uc_allocbucket != NULL && (cache->uc_allocbucket->ub_cnt < cache->uc_freebucket->ub_cnt)) { ZONE_UNLOCK(zone); goto zfree_start; } } /* Since we have locked the zone we may as well send back our stats */ zone->uz_allocs += cache->uc_allocs; cache->uc_allocs = 0; zone->uz_frees += cache->uc_frees; cache->uc_frees = 0; bucket = cache->uc_freebucket; cache->uc_freebucket = NULL; /* Can we throw this on the zone full list? */ if (bucket != NULL) { #ifdef UMA_DEBUG_ALLOC printf("uma_zfree: Putting old bucket on the free list.\n"); #endif /* ub_cnt is pointing to the last free item */ KASSERT(bucket->ub_cnt != 0, ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n")); LIST_INSERT_HEAD(&zone->uz_full_bucket, bucket, ub_link); } if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) { LIST_REMOVE(bucket, ub_link); ZONE_UNLOCK(zone); cache->uc_freebucket = bucket; goto zfree_start; } /* We are no longer associated with this CPU. */ critical_exit(); /* And the zone.. */ ZONE_UNLOCK(zone); #ifdef UMA_DEBUG_ALLOC printf("uma_zfree: Allocating new free bucket.\n"); #endif bflags = M_NOWAIT; if (zone->uz_flags & UMA_ZFLAG_CACHEONLY) bflags |= M_NOVM; bucket = bucket_alloc(zone->uz_count, bflags); if (bucket) { ZONE_LOCK(zone); LIST_INSERT_HEAD(&zone->uz_free_bucket, bucket, ub_link); ZONE_UNLOCK(zone); goto zfree_restart; } /* * If nothing else caught this, we'll just do an internal free. */ zfree_internal: zone_free_item(zone, item, udata, SKIP_DTOR, ZFREE_STATFREE); return; } /* * Frees an item to an INTERNAL zone or allocates a free bucket * * Arguments: * zone The zone to free to * item The item we're freeing * udata User supplied data for the dtor * skip Skip dtors and finis */ static void zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip, int flags) { uma_slab_t slab; uma_slabrefcnt_t slabref; uma_keg_t keg; u_int8_t *mem; u_int8_t freei; int clearfull; if (skip < SKIP_DTOR && zone->uz_dtor) zone->uz_dtor(item, zone->uz_size, udata); if (skip < SKIP_FINI && zone->uz_fini) zone->uz_fini(item, zone->uz_size); ZONE_LOCK(zone); if (flags & ZFREE_STATFAIL) zone->uz_fails++; if (flags & ZFREE_STATFREE) zone->uz_frees++; if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) { mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK)); keg = zone_first_keg(zone); /* Must only be one. */ if (zone->uz_flags & UMA_ZONE_HASH) { slab = hash_sfind(&keg->uk_hash, mem); } else { mem += keg->uk_pgoff; slab = (uma_slab_t)mem; } } else { /* This prevents redundant lookups via free(). */ if ((zone->uz_flags & UMA_ZONE_MALLOC) && udata != NULL) slab = (uma_slab_t)udata; else slab = vtoslab((vm_offset_t)item); keg = slab->us_keg; keg_relock(keg, zone); } MPASS(keg == slab->us_keg); /* Do we need to remove from any lists? */ if (slab->us_freecount+1 == keg->uk_ipers) { LIST_REMOVE(slab, us_link); LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link); } else if (slab->us_freecount == 0) { LIST_REMOVE(slab, us_link); LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link); } /* Slab management stuff */ freei = ((unsigned long)item - (unsigned long)slab->us_data) / keg->uk_rsize; #ifdef INVARIANTS if (!skip) uma_dbg_free(zone, slab, item); #endif if (keg->uk_flags & UMA_ZONE_REFCNT) { slabref = (uma_slabrefcnt_t)slab; slabref->us_freelist[freei].us_item = slab->us_firstfree; } else { slab->us_freelist[freei].us_item = slab->us_firstfree; } slab->us_firstfree = freei; slab->us_freecount++; /* Zone statistics */ keg->uk_free++; clearfull = 0; if (keg->uk_flags & UMA_ZFLAG_FULL) { if (keg->uk_pages < keg->uk_maxpages) { keg->uk_flags &= ~UMA_ZFLAG_FULL; clearfull = 1; } /* * We can handle one more allocation. Since we're clearing ZFLAG_FULL, * wake up all procs blocked on pages. This should be uncommon, so * keeping this simple for now (rather than adding count of blocked * threads etc). */ wakeup(keg); } if (clearfull) { zone_relock(zone, keg); zone->uz_flags &= ~UMA_ZFLAG_FULL; wakeup(zone); ZONE_UNLOCK(zone); } else KEG_UNLOCK(keg); } /* See uma.h */ void uma_zone_set_max(uma_zone_t zone, int nitems) { uma_keg_t keg; ZONE_LOCK(zone); keg = zone_first_keg(zone); keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera; if (keg->uk_maxpages * keg->uk_ipers < nitems) keg->uk_maxpages += keg->uk_ppera; ZONE_UNLOCK(zone); } /* See uma.h */ void uma_zone_set_init(uma_zone_t zone, uma_init uminit) { uma_keg_t keg; ZONE_LOCK(zone); keg = zone_first_keg(zone); KASSERT(keg->uk_pages == 0, ("uma_zone_set_init on non-empty keg")); keg->uk_init = uminit; ZONE_UNLOCK(zone); } /* See uma.h */ void uma_zone_set_fini(uma_zone_t zone, uma_fini fini) { uma_keg_t keg; ZONE_LOCK(zone); keg = zone_first_keg(zone); KASSERT(keg->uk_pages == 0, ("uma_zone_set_fini on non-empty keg")); keg->uk_fini = fini; ZONE_UNLOCK(zone); } /* See uma.h */ void uma_zone_set_zinit(uma_zone_t zone, uma_init zinit) { ZONE_LOCK(zone); KASSERT(zone_first_keg(zone)->uk_pages == 0, ("uma_zone_set_zinit on non-empty keg")); zone->uz_init = zinit; ZONE_UNLOCK(zone); } /* See uma.h */ void uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini) { ZONE_LOCK(zone); KASSERT(zone_first_keg(zone)->uk_pages == 0, ("uma_zone_set_zfini on non-empty keg")); zone->uz_fini = zfini; ZONE_UNLOCK(zone); } /* See uma.h */ /* XXX uk_freef is not actually used with the zone locked */ void uma_zone_set_freef(uma_zone_t zone, uma_free freef) { ZONE_LOCK(zone); zone_first_keg(zone)->uk_freef = freef; ZONE_UNLOCK(zone); } /* See uma.h */ /* XXX uk_allocf is not actually used with the zone locked */ void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf) { uma_keg_t keg; ZONE_LOCK(zone); keg = zone_first_keg(zone); keg->uk_flags |= UMA_ZFLAG_PRIVALLOC; keg->uk_allocf = allocf; ZONE_UNLOCK(zone); } /* See uma.h */ int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int count) { uma_keg_t keg; vm_offset_t kva; int pages; keg = zone_first_keg(zone); pages = count / keg->uk_ipers; if (pages * keg->uk_ipers < count) pages++; kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE); if (kva == 0) return (0); if (obj == NULL) obj = vm_object_allocate(OBJT_PHYS, pages); else { VM_OBJECT_LOCK_INIT(obj, "uma object"); _vm_object_allocate(OBJT_PHYS, pages, obj); } ZONE_LOCK(zone); keg->uk_kva = kva; keg->uk_obj = obj; keg->uk_maxpages = pages; keg->uk_allocf = obj_alloc; keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC; ZONE_UNLOCK(zone); return (1); } /* See uma.h */ void uma_prealloc(uma_zone_t zone, int items) { int slabs; uma_slab_t slab; uma_keg_t keg; keg = zone_first_keg(zone); ZONE_LOCK(zone); slabs = items / keg->uk_ipers; if (slabs * keg->uk_ipers < items) slabs++; while (slabs > 0) { slab = keg_alloc_slab(keg, zone, M_WAITOK); if (slab == NULL) break; MPASS(slab->us_keg == keg); LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link); slabs--; } ZONE_UNLOCK(zone); } /* See uma.h */ u_int32_t * uma_find_refcnt(uma_zone_t zone, void *item) { uma_slabrefcnt_t slabref; uma_keg_t keg; u_int32_t *refcnt; int idx; slabref = (uma_slabrefcnt_t)vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK)); keg = slabref->us_keg; KASSERT(slabref != NULL && slabref->us_keg->uk_flags & UMA_ZONE_REFCNT, ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT")); idx = ((unsigned long)item - (unsigned long)slabref->us_data) / keg->uk_rsize; refcnt = &slabref->us_freelist[idx].us_refcnt; return refcnt; } /* See uma.h */ void uma_reclaim(void) { #ifdef UMA_DEBUG printf("UMA: vm asked us to release pages!\n"); #endif bucket_enable(); zone_foreach(zone_drain); /* * Some slabs may have been freed but this zone will be visited early * we visit again so that we can free pages that are empty once other * zones are drained. We have to do the same for buckets. */ zone_drain(slabzone); zone_drain(slabrefzone); bucket_zone_drain(); } /* See uma.h */ int uma_zone_exhausted(uma_zone_t zone) { int full; ZONE_LOCK(zone); full = (zone->uz_flags & UMA_ZFLAG_FULL); ZONE_UNLOCK(zone); return (full); } int uma_zone_exhausted_nolock(uma_zone_t zone) { return (zone->uz_flags & UMA_ZFLAG_FULL); } void * uma_large_malloc(int size, int wait) { void *mem; uma_slab_t slab; u_int8_t flags; slab = zone_alloc_item(slabzone, NULL, wait); if (slab == NULL) return (NULL); mem = page_alloc(NULL, size, &flags, wait); if (mem) { vsetslab((vm_offset_t)mem, slab); slab->us_data = mem; slab->us_flags = flags | UMA_SLAB_MALLOC; slab->us_size = size; } else { zone_free_item(slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFAIL | ZFREE_STATFREE); } return (mem); } void uma_large_free(uma_slab_t slab) { vsetobj((vm_offset_t)slab->us_data, kmem_object); page_free(slab->us_data, slab->us_size, slab->us_flags); zone_free_item(slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE); } void uma_print_stats(void) { zone_foreach(uma_print_zone); } static void slab_print(uma_slab_t slab) { printf("slab: keg %p, data %p, freecount %d, firstfree %d\n", slab->us_keg, slab->us_data, slab->us_freecount, slab->us_firstfree); } static void cache_print(uma_cache_t cache) { printf("alloc: %p(%d), free: %p(%d)\n", cache->uc_allocbucket, cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0, cache->uc_freebucket, cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0); } static void uma_print_keg(uma_keg_t keg) { uma_slab_t slab; printf("keg: %s(%p) size %d(%d) flags %d ipers %d ppera %d " "out %d free %d limit %d\n", keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags, keg->uk_ipers, keg->uk_ppera, (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free, (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers); printf("Part slabs:\n"); LIST_FOREACH(slab, &keg->uk_part_slab, us_link) slab_print(slab); printf("Free slabs:\n"); LIST_FOREACH(slab, &keg->uk_free_slab, us_link) slab_print(slab); printf("Full slabs:\n"); LIST_FOREACH(slab, &keg->uk_full_slab, us_link) slab_print(slab); } void uma_print_zone(uma_zone_t zone) { uma_cache_t cache; uma_klink_t kl; int i; printf("zone: %s(%p) size %d flags %d\n", zone->uz_name, zone, zone->uz_size, zone->uz_flags); LIST_FOREACH(kl, &zone->uz_kegs, kl_link) uma_print_keg(kl->kl_keg); CPU_FOREACH(i) { cache = &zone->uz_cpu[i]; printf("CPU %d Cache:\n", i); cache_print(cache); } } #ifdef DDB /* * Generate statistics across both the zone and its per-cpu cache's. Return * desired statistics if the pointer is non-NULL for that statistic. * * Note: does not update the zone statistics, as it can't safely clear the * per-CPU cache statistic. * * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't * safe from off-CPU; we should modify the caches to track this information * directly so that we don't have to. */ static void uma_zone_sumstat(uma_zone_t z, int *cachefreep, u_int64_t *allocsp, u_int64_t *freesp) { uma_cache_t cache; u_int64_t allocs, frees; int cachefree, cpu; allocs = frees = 0; cachefree = 0; CPU_FOREACH(cpu) { cache = &z->uz_cpu[cpu]; if (cache->uc_allocbucket != NULL) cachefree += cache->uc_allocbucket->ub_cnt; if (cache->uc_freebucket != NULL) cachefree += cache->uc_freebucket->ub_cnt; allocs += cache->uc_allocs; frees += cache->uc_frees; } allocs += z->uz_allocs; frees += z->uz_frees; if (cachefreep != NULL) *cachefreep = cachefree; if (allocsp != NULL) *allocsp = allocs; if (freesp != NULL) *freesp = frees; } #endif /* DDB */ static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS) { uma_keg_t kz; uma_zone_t z; int count; count = 0; mtx_lock(&uma_mtx); LIST_FOREACH(kz, &uma_kegs, uk_link) { LIST_FOREACH(z, &kz->uk_zones, uz_link) count++; } mtx_unlock(&uma_mtx); return (sysctl_handle_int(oidp, &count, 0, req)); } static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS) { struct uma_stream_header ush; struct uma_type_header uth; struct uma_percpu_stat ups; uma_bucket_t bucket; struct sbuf sbuf; uma_cache_t cache; uma_klink_t kl; uma_keg_t kz; uma_zone_t z; uma_keg_t k; char *buffer; int buflen, count, error, i; mtx_lock(&uma_mtx); restart: mtx_assert(&uma_mtx, MA_OWNED); count = 0; LIST_FOREACH(kz, &uma_kegs, uk_link) { LIST_FOREACH(z, &kz->uk_zones, uz_link) count++; } mtx_unlock(&uma_mtx); buflen = sizeof(ush) + count * (sizeof(uth) + sizeof(ups) * (mp_maxid + 1)) + 1; buffer = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO); mtx_lock(&uma_mtx); i = 0; LIST_FOREACH(kz, &uma_kegs, uk_link) { LIST_FOREACH(z, &kz->uk_zones, uz_link) i++; } if (i > count) { free(buffer, M_TEMP); goto restart; } count = i; sbuf_new(&sbuf, buffer, buflen, SBUF_FIXEDLEN); /* * Insert stream header. */ bzero(&ush, sizeof(ush)); ush.ush_version = UMA_STREAM_VERSION; ush.ush_maxcpus = (mp_maxid + 1); ush.ush_count = count; if (sbuf_bcat(&sbuf, &ush, sizeof(ush)) < 0) { mtx_unlock(&uma_mtx); error = ENOMEM; goto out; } LIST_FOREACH(kz, &uma_kegs, uk_link) { LIST_FOREACH(z, &kz->uk_zones, uz_link) { bzero(&uth, sizeof(uth)); ZONE_LOCK(z); strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME); uth.uth_align = kz->uk_align; uth.uth_size = kz->uk_size; uth.uth_rsize = kz->uk_rsize; LIST_FOREACH(kl, &z->uz_kegs, kl_link) { k = kl->kl_keg; uth.uth_maxpages += k->uk_maxpages; uth.uth_pages += k->uk_pages; uth.uth_keg_free += k->uk_free; uth.uth_limit = (k->uk_maxpages / k->uk_ppera) * k->uk_ipers; } /* * A zone is secondary is it is not the first entry * on the keg's zone list. */ if ((z->uz_flags & UMA_ZONE_SECONDARY) && (LIST_FIRST(&kz->uk_zones) != z)) uth.uth_zone_flags = UTH_ZONE_SECONDARY; LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link) uth.uth_zone_free += bucket->ub_cnt; uth.uth_allocs = z->uz_allocs; uth.uth_frees = z->uz_frees; uth.uth_fails = z->uz_fails; if (sbuf_bcat(&sbuf, &uth, sizeof(uth)) < 0) { ZONE_UNLOCK(z); mtx_unlock(&uma_mtx); error = ENOMEM; goto out; } /* * While it is not normally safe to access the cache * bucket pointers while not on the CPU that owns the * cache, we only allow the pointers to be exchanged * without the zone lock held, not invalidated, so * accept the possible race associated with bucket * exchange during monitoring. */ for (i = 0; i < (mp_maxid + 1); i++) { bzero(&ups, sizeof(ups)); if (kz->uk_flags & UMA_ZFLAG_INTERNAL) goto skip; if (CPU_ABSENT(i)) goto skip; cache = &z->uz_cpu[i]; if (cache->uc_allocbucket != NULL) ups.ups_cache_free += cache->uc_allocbucket->ub_cnt; if (cache->uc_freebucket != NULL) ups.ups_cache_free += cache->uc_freebucket->ub_cnt; ups.ups_allocs = cache->uc_allocs; ups.ups_frees = cache->uc_frees; skip: if (sbuf_bcat(&sbuf, &ups, sizeof(ups)) < 0) { ZONE_UNLOCK(z); mtx_unlock(&uma_mtx); error = ENOMEM; goto out; } } ZONE_UNLOCK(z); } } mtx_unlock(&uma_mtx); sbuf_finish(&sbuf); error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf)); out: free(buffer, M_TEMP); return (error); } #ifdef DDB DB_SHOW_COMMAND(uma, db_show_uma) { u_int64_t allocs, frees; uma_bucket_t bucket; uma_keg_t kz; uma_zone_t z; int cachefree; db_printf("%18s %8s %8s %8s %12s\n", "Zone", "Size", "Used", "Free", "Requests"); LIST_FOREACH(kz, &uma_kegs, uk_link) { LIST_FOREACH(z, &kz->uk_zones, uz_link) { if (kz->uk_flags & UMA_ZFLAG_INTERNAL) { allocs = z->uz_allocs; frees = z->uz_frees; cachefree = 0; } else uma_zone_sumstat(z, &cachefree, &allocs, &frees); if (!((z->uz_flags & UMA_ZONE_SECONDARY) && (LIST_FIRST(&kz->uk_zones) != z))) cachefree += kz->uk_free; LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link) cachefree += bucket->ub_cnt; db_printf("%18s %8ju %8jd %8d %12ju\n", z->uz_name, (uintmax_t)kz->uk_size, (intmax_t)(allocs - frees), cachefree, (uintmax_t)allocs); } } } #endif