The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/vm/uma_core.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
    3  * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
    4  * Copyright (c) 2004-2005 Robert N. M. Watson
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice unmodified, this list of conditions, and the following
   12  *    disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   27  */
   28 
   29 /*
   30  * uma_core.c  Implementation of the Universal Memory allocator
   31  *
   32  * This allocator is intended to replace the multitude of similar object caches
   33  * in the standard FreeBSD kernel.  The intent is to be flexible as well as
   34  * effecient.  A primary design goal is to return unused memory to the rest of
   35  * the system.  This will make the system as a whole more flexible due to the
   36  * ability to move memory to subsystems which most need it instead of leaving
   37  * pools of reserved memory unused.
   38  *
   39  * The basic ideas stem from similar slab/zone based allocators whose algorithms
   40  * are well known.
   41  *
   42  */
   43 
   44 /*
   45  * TODO:
   46  *      - Improve memory usage for large allocations
   47  *      - Investigate cache size adjustments
   48  */
   49 
   50 #include <sys/cdefs.h>
   51 __FBSDID("$FreeBSD$");
   52 
   53 /* I should really use ktr.. */
   54 /*
   55 #define UMA_DEBUG 1
   56 #define UMA_DEBUG_ALLOC 1
   57 #define UMA_DEBUG_ALLOC_1 1
   58 */
   59 
   60 #include "opt_ddb.h"
   61 #include "opt_param.h"
   62 
   63 #include <sys/param.h>
   64 #include <sys/systm.h>
   65 #include <sys/kernel.h>
   66 #include <sys/types.h>
   67 #include <sys/queue.h>
   68 #include <sys/malloc.h>
   69 #include <sys/ktr.h>
   70 #include <sys/lock.h>
   71 #include <sys/sysctl.h>
   72 #include <sys/mutex.h>
   73 #include <sys/proc.h>
   74 #include <sys/sbuf.h>
   75 #include <sys/smp.h>
   76 #include <sys/vmmeter.h>
   77 
   78 #include <vm/vm.h>
   79 #include <vm/vm_object.h>
   80 #include <vm/vm_page.h>
   81 #include <vm/vm_param.h>
   82 #include <vm/vm_map.h>
   83 #include <vm/vm_kern.h>
   84 #include <vm/vm_extern.h>
   85 #include <vm/uma.h>
   86 #include <vm/uma_int.h>
   87 #include <vm/uma_dbg.h>
   88 
   89 #include <machine/vmparam.h>
   90 
   91 #include <ddb/ddb.h>
   92 
   93 /*
   94  * This is the zone and keg from which all zones are spawned.  The idea is that
   95  * even the zone & keg heads are allocated from the allocator, so we use the
   96  * bss section to bootstrap us.
   97  */
   98 static struct uma_keg masterkeg;
   99 static struct uma_zone masterzone_k;
  100 static struct uma_zone masterzone_z;
  101 static uma_zone_t kegs = &masterzone_k;
  102 static uma_zone_t zones = &masterzone_z;
  103 
  104 /* This is the zone from which all of uma_slab_t's are allocated. */
  105 static uma_zone_t slabzone;
  106 static uma_zone_t slabrefzone;  /* With refcounters (for UMA_ZONE_REFCNT) */
  107 
  108 /*
  109  * The initial hash tables come out of this zone so they can be allocated
  110  * prior to malloc coming up.
  111  */
  112 static uma_zone_t hashzone;
  113 
  114 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
  115 
  116 /*
  117  * Are we allowed to allocate buckets?
  118  */
  119 static int bucketdisable = 1;
  120 
  121 /* Linked list of all kegs in the system */
  122 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(&uma_kegs);
  123 
  124 /* This mutex protects the keg list */
  125 static struct mtx uma_mtx;
  126 
  127 /* Linked list of boot time pages */
  128 static LIST_HEAD(,uma_slab) uma_boot_pages =
  129     LIST_HEAD_INITIALIZER(&uma_boot_pages);
  130 
  131 /* This mutex protects the boot time pages list */
  132 static struct mtx uma_boot_pages_mtx;
  133 
  134 /* Is the VM done starting up? */
  135 static int booted = 0;
  136 
  137 /* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */
  138 static u_int uma_max_ipers;
  139 static u_int uma_max_ipers_ref;
  140 
  141 /*
  142  * This is the handle used to schedule events that need to happen
  143  * outside of the allocation fast path.
  144  */
  145 static struct callout uma_callout;
  146 #define UMA_TIMEOUT     20              /* Seconds for callout interval. */
  147 
  148 /*
  149  * This structure is passed as the zone ctor arg so that I don't have to create
  150  * a special allocation function just for zones.
  151  */
  152 struct uma_zctor_args {
  153         char *name;
  154         size_t size;
  155         uma_ctor ctor;
  156         uma_dtor dtor;
  157         uma_init uminit;
  158         uma_fini fini;
  159         uma_keg_t keg;
  160         int align;
  161         u_int32_t flags;
  162 };
  163 
  164 struct uma_kctor_args {
  165         uma_zone_t zone;
  166         size_t size;
  167         uma_init uminit;
  168         uma_fini fini;
  169         int align;
  170         u_int32_t flags;
  171 };
  172 
  173 struct uma_bucket_zone {
  174         uma_zone_t      ubz_zone;
  175         char            *ubz_name;
  176         int             ubz_entries;
  177 };
  178 
  179 #define BUCKET_MAX      128
  180 
  181 struct uma_bucket_zone bucket_zones[] = {
  182         { NULL, "16 Bucket", 16 },
  183         { NULL, "32 Bucket", 32 },
  184         { NULL, "64 Bucket", 64 },
  185         { NULL, "128 Bucket", 128 },
  186         { NULL, NULL, 0}
  187 };
  188 
  189 #define BUCKET_SHIFT    4
  190 #define BUCKET_ZONES    ((BUCKET_MAX >> BUCKET_SHIFT) + 1)
  191 
  192 /*
  193  * bucket_size[] maps requested bucket sizes to zones that allocate a bucket
  194  * of approximately the right size.
  195  */
  196 static uint8_t bucket_size[BUCKET_ZONES];
  197 
  198 /*
  199  * Flags and enumerations to be passed to internal functions.
  200  */
  201 enum zfreeskip { SKIP_NONE, SKIP_DTOR, SKIP_FINI };
  202 
  203 #define ZFREE_STATFAIL  0x00000001      /* Update zone failure statistic. */
  204 #define ZFREE_STATFREE  0x00000002      /* Update zone free statistic. */
  205 
  206 /* Prototypes.. */
  207 
  208 static void *obj_alloc(uma_zone_t, int, u_int8_t *, int);
  209 static void *page_alloc(uma_zone_t, int, u_int8_t *, int);
  210 static void *startup_alloc(uma_zone_t, int, u_int8_t *, int);
  211 static void page_free(void *, int, u_int8_t);
  212 static uma_slab_t slab_zalloc(uma_zone_t, int);
  213 static void cache_drain(uma_zone_t);
  214 static void bucket_drain(uma_zone_t, uma_bucket_t);
  215 static void bucket_cache_drain(uma_zone_t zone);
  216 static int keg_ctor(void *, int, void *, int);
  217 static void keg_dtor(void *, int, void *);
  218 static int zone_ctor(void *, int, void *, int);
  219 static void zone_dtor(void *, int, void *);
  220 static int zero_init(void *, int, int);
  221 static void zone_small_init(uma_zone_t zone);
  222 static void zone_large_init(uma_zone_t zone);
  223 static void zone_foreach(void (*zfunc)(uma_zone_t));
  224 static void zone_timeout(uma_zone_t zone);
  225 static int hash_alloc(struct uma_hash *);
  226 static int hash_expand(struct uma_hash *, struct uma_hash *);
  227 static void hash_free(struct uma_hash *hash);
  228 static void uma_timeout(void *);
  229 static void uma_startup3(void);
  230 static void *uma_zalloc_internal(uma_zone_t, void *, int);
  231 static void uma_zfree_internal(uma_zone_t, void *, void *, enum zfreeskip,
  232     int);
  233 static void bucket_enable(void);
  234 static void bucket_init(void);
  235 static uma_bucket_t bucket_alloc(int, int);
  236 static void bucket_free(uma_bucket_t);
  237 static void bucket_zone_drain(void);
  238 static int uma_zalloc_bucket(uma_zone_t zone, int flags);
  239 static uma_slab_t uma_zone_slab(uma_zone_t zone, int flags);
  240 static void *uma_slab_alloc(uma_zone_t zone, uma_slab_t slab);
  241 static uma_zone_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
  242     uma_fini fini, int align, u_int32_t flags);
  243 
  244 void uma_print_zone(uma_zone_t);
  245 void uma_print_stats(void);
  246 static int sysctl_vm_zone(SYSCTL_HANDLER_ARGS);
  247 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
  248 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
  249 
  250 #ifdef WITNESS
  251 static int nosleepwithlocks = 1;
  252 SYSCTL_INT(_debug, OID_AUTO, nosleepwithlocks, CTLFLAG_RW, &nosleepwithlocks,
  253     0, "Convert M_WAITOK to M_NOWAIT to avoid lock-held-across-sleep paths");
  254 #else
  255 static int nosleepwithlocks = 0;
  256 SYSCTL_INT(_debug, OID_AUTO, nosleepwithlocks, CTLFLAG_RW, &nosleepwithlocks,
  257     0, "Convert M_WAITOK to M_NOWAIT to avoid lock-held-across-sleep paths");
  258 #endif
  259 SYSCTL_OID(_vm, OID_AUTO, zone, CTLTYPE_STRING|CTLFLAG_RD,
  260     NULL, 0, sysctl_vm_zone, "A", "Zone Info");
  261 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
  262 
  263 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
  264     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
  265 
  266 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
  267     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
  268 
  269 /*
  270  * This routine checks to see whether or not it's safe to enable buckets.
  271  */
  272 
  273 static void
  274 bucket_enable(void)
  275 {
  276         if (cnt.v_free_count < cnt.v_free_min)
  277                 bucketdisable = 1;
  278         else
  279                 bucketdisable = 0;
  280 }
  281 
  282 /*
  283  * Initialize bucket_zones, the array of zones of buckets of various sizes.
  284  *
  285  * For each zone, calculate the memory required for each bucket, consisting
  286  * of the header and an array of pointers.  Initialize bucket_size[] to point
  287  * the range of appropriate bucket sizes at the zone.
  288  */
  289 static void
  290 bucket_init(void)
  291 {
  292         struct uma_bucket_zone *ubz;
  293         int i;
  294         int j;
  295 
  296         for (i = 0, j = 0; bucket_zones[j].ubz_entries != 0; j++) {
  297                 int size;
  298 
  299                 ubz = &bucket_zones[j];
  300                 size = roundup(sizeof(struct uma_bucket), sizeof(void *));
  301                 size += sizeof(void *) * ubz->ubz_entries;
  302                 ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
  303                     NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
  304                 for (; i <= ubz->ubz_entries; i += (1 << BUCKET_SHIFT))
  305                         bucket_size[i >> BUCKET_SHIFT] = j;
  306         }
  307 }
  308 
  309 /*
  310  * Given a desired number of entries for a bucket, return the zone from which
  311  * to allocate the bucket.
  312  */
  313 static struct uma_bucket_zone *
  314 bucket_zone_lookup(int entries)
  315 {
  316         int idx;
  317 
  318         idx = howmany(entries, 1 << BUCKET_SHIFT);
  319         return (&bucket_zones[bucket_size[idx]]);
  320 }
  321 
  322 static uma_bucket_t
  323 bucket_alloc(int entries, int bflags)
  324 {
  325         struct uma_bucket_zone *ubz;
  326         uma_bucket_t bucket;
  327 
  328         /*
  329          * This is to stop us from allocating per cpu buckets while we're
  330          * running out of vm.boot_pages.  Otherwise, we would exhaust the
  331          * boot pages.  This also prevents us from allocating buckets in
  332          * low memory situations.
  333          */
  334         if (bucketdisable)
  335                 return (NULL);
  336 
  337         ubz = bucket_zone_lookup(entries);
  338         bucket = uma_zalloc_internal(ubz->ubz_zone, NULL, bflags);
  339         if (bucket) {
  340 #ifdef INVARIANTS
  341                 bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
  342 #endif
  343                 bucket->ub_cnt = 0;
  344                 bucket->ub_entries = ubz->ubz_entries;
  345         }
  346 
  347         return (bucket);
  348 }
  349 
  350 static void
  351 bucket_free(uma_bucket_t bucket)
  352 {
  353         struct uma_bucket_zone *ubz;
  354 
  355         ubz = bucket_zone_lookup(bucket->ub_entries);
  356         uma_zfree_internal(ubz->ubz_zone, bucket, NULL, SKIP_NONE,
  357             ZFREE_STATFREE);
  358 }
  359 
  360 static void
  361 bucket_zone_drain(void)
  362 {
  363         struct uma_bucket_zone *ubz;
  364 
  365         for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
  366                 zone_drain(ubz->ubz_zone);
  367 }
  368 
  369 
  370 /*
  371  * Routine called by timeout which is used to fire off some time interval
  372  * based calculations.  (stats, hash size, etc.)
  373  *
  374  * Arguments:
  375  *      arg   Unused
  376  *
  377  * Returns:
  378  *      Nothing
  379  */
  380 static void
  381 uma_timeout(void *unused)
  382 {
  383         bucket_enable();
  384         zone_foreach(zone_timeout);
  385 
  386         /* Reschedule this event */
  387         callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
  388 }
  389 
  390 /*
  391  * Routine to perform timeout driven calculations.  This expands the
  392  * hashes and does per cpu statistics aggregation.
  393  *
  394  *  Arguments:
  395  *      zone  The zone to operate on
  396  *
  397  *  Returns:
  398  *      Nothing
  399  */
  400 static void
  401 zone_timeout(uma_zone_t zone)
  402 {
  403         uma_keg_t keg;
  404         u_int64_t alloc;
  405 
  406         keg = zone->uz_keg;
  407         alloc = 0;
  408 
  409         /*
  410          * Expand the zone hash table.
  411          *
  412          * This is done if the number of slabs is larger than the hash size.
  413          * What I'm trying to do here is completely reduce collisions.  This
  414          * may be a little aggressive.  Should I allow for two collisions max?
  415          */
  416         ZONE_LOCK(zone);
  417         if (keg->uk_flags & UMA_ZONE_HASH &&
  418             keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
  419                 struct uma_hash newhash;
  420                 struct uma_hash oldhash;
  421                 int ret;
  422 
  423                 /*
  424                  * This is so involved because allocating and freeing
  425                  * while the zone lock is held will lead to deadlock.
  426                  * I have to do everything in stages and check for
  427                  * races.
  428                  */
  429                 newhash = keg->uk_hash;
  430                 ZONE_UNLOCK(zone);
  431                 ret = hash_alloc(&newhash);
  432                 ZONE_LOCK(zone);
  433                 if (ret) {
  434                         if (hash_expand(&keg->uk_hash, &newhash)) {
  435                                 oldhash = keg->uk_hash;
  436                                 keg->uk_hash = newhash;
  437                         } else
  438                                 oldhash = newhash;
  439 
  440                         ZONE_UNLOCK(zone);
  441                         hash_free(&oldhash);
  442                         ZONE_LOCK(zone);
  443                 }
  444         }
  445         ZONE_UNLOCK(zone);
  446 }
  447 
  448 /*
  449  * Allocate and zero fill the next sized hash table from the appropriate
  450  * backing store.
  451  *
  452  * Arguments:
  453  *      hash  A new hash structure with the old hash size in uh_hashsize
  454  *
  455  * Returns:
  456  *      1 on sucess and 0 on failure.
  457  */
  458 static int
  459 hash_alloc(struct uma_hash *hash)
  460 {
  461         int oldsize;
  462         int alloc;
  463 
  464         oldsize = hash->uh_hashsize;
  465 
  466         /* We're just going to go to a power of two greater */
  467         if (oldsize)  {
  468                 hash->uh_hashsize = oldsize * 2;
  469                 alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
  470                 hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
  471                     M_UMAHASH, M_NOWAIT);
  472         } else {
  473                 alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
  474                 hash->uh_slab_hash = uma_zalloc_internal(hashzone, NULL,
  475                     M_WAITOK);
  476                 hash->uh_hashsize = UMA_HASH_SIZE_INIT;
  477         }
  478         if (hash->uh_slab_hash) {
  479                 bzero(hash->uh_slab_hash, alloc);
  480                 hash->uh_hashmask = hash->uh_hashsize - 1;
  481                 return (1);
  482         }
  483 
  484         return (0);
  485 }
  486 
  487 /*
  488  * Expands the hash table for HASH zones.  This is done from zone_timeout
  489  * to reduce collisions.  This must not be done in the regular allocation
  490  * path, otherwise, we can recurse on the vm while allocating pages.
  491  *
  492  * Arguments:
  493  *      oldhash  The hash you want to expand
  494  *      newhash  The hash structure for the new table
  495  *
  496  * Returns:
  497  *      Nothing
  498  *
  499  * Discussion:
  500  */
  501 static int
  502 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
  503 {
  504         uma_slab_t slab;
  505         int hval;
  506         int i;
  507 
  508         if (!newhash->uh_slab_hash)
  509                 return (0);
  510 
  511         if (oldhash->uh_hashsize >= newhash->uh_hashsize)
  512                 return (0);
  513 
  514         /*
  515          * I need to investigate hash algorithms for resizing without a
  516          * full rehash.
  517          */
  518 
  519         for (i = 0; i < oldhash->uh_hashsize; i++)
  520                 while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
  521                         slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
  522                         SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
  523                         hval = UMA_HASH(newhash, slab->us_data);
  524                         SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
  525                             slab, us_hlink);
  526                 }
  527 
  528         return (1);
  529 }
  530 
  531 /*
  532  * Free the hash bucket to the appropriate backing store.
  533  *
  534  * Arguments:
  535  *      slab_hash  The hash bucket we're freeing
  536  *      hashsize   The number of entries in that hash bucket
  537  *
  538  * Returns:
  539  *      Nothing
  540  */
  541 static void
  542 hash_free(struct uma_hash *hash)
  543 {
  544         if (hash->uh_slab_hash == NULL)
  545                 return;
  546         if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
  547                 uma_zfree_internal(hashzone,
  548                     hash->uh_slab_hash, NULL, SKIP_NONE, ZFREE_STATFREE);
  549         else
  550                 free(hash->uh_slab_hash, M_UMAHASH);
  551 }
  552 
  553 /*
  554  * Frees all outstanding items in a bucket
  555  *
  556  * Arguments:
  557  *      zone   The zone to free to, must be unlocked.
  558  *      bucket The free/alloc bucket with items, cpu queue must be locked.
  559  *
  560  * Returns:
  561  *      Nothing
  562  */
  563 
  564 static void
  565 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
  566 {
  567         uma_slab_t slab;
  568         int mzone;
  569         void *item;
  570 
  571         if (bucket == NULL)
  572                 return;
  573 
  574         slab = NULL;
  575         mzone = 0;
  576 
  577         /* We have to lookup the slab again for malloc.. */
  578         if (zone->uz_keg->uk_flags & UMA_ZONE_MALLOC)
  579                 mzone = 1;
  580 
  581         while (bucket->ub_cnt > 0)  {
  582                 bucket->ub_cnt--;
  583                 item = bucket->ub_bucket[bucket->ub_cnt];
  584 #ifdef INVARIANTS
  585                 bucket->ub_bucket[bucket->ub_cnt] = NULL;
  586                 KASSERT(item != NULL,
  587                     ("bucket_drain: botched ptr, item is NULL"));
  588 #endif
  589                 /*
  590                  * This is extremely inefficient.  The slab pointer was passed
  591                  * to uma_zfree_arg, but we lost it because the buckets don't
  592                  * hold them.  This will go away when free() gets a size passed
  593                  * to it.
  594                  */
  595                 if (mzone)
  596                         slab = vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK));
  597                 uma_zfree_internal(zone, item, slab, SKIP_DTOR, 0);
  598         }
  599 }
  600 
  601 /*
  602  * Drains the per cpu caches for a zone.
  603  *
  604  * NOTE: This may only be called while the zone is being turn down, and not
  605  * during normal operation.  This is necessary in order that we do not have
  606  * to migrate CPUs to drain the per-CPU caches.
  607  *
  608  * Arguments:
  609  *      zone     The zone to drain, must be unlocked.
  610  *
  611  * Returns:
  612  *      Nothing
  613  */
  614 static void
  615 cache_drain(uma_zone_t zone)
  616 {
  617         uma_cache_t cache;
  618         int cpu;
  619 
  620         /*
  621          * XXX: It is safe to not lock the per-CPU caches, because we're
  622          * tearing down the zone anyway.  I.e., there will be no further use
  623          * of the caches at this point.
  624          *
  625          * XXX: It would good to be able to assert that the zone is being
  626          * torn down to prevent improper use of cache_drain().
  627          *
  628          * XXX: We lock the zone before passing into bucket_cache_drain() as
  629          * it is used elsewhere.  Should the tear-down path be made special
  630          * there in some form?
  631          */
  632         for (cpu = 0; cpu <= mp_maxid; cpu++) {
  633                 if (CPU_ABSENT(cpu))
  634                         continue;
  635                 cache = &zone->uz_cpu[cpu];
  636                 bucket_drain(zone, cache->uc_allocbucket);
  637                 bucket_drain(zone, cache->uc_freebucket);
  638                 if (cache->uc_allocbucket != NULL)
  639                         bucket_free(cache->uc_allocbucket);
  640                 if (cache->uc_freebucket != NULL)
  641                         bucket_free(cache->uc_freebucket);
  642                 cache->uc_allocbucket = cache->uc_freebucket = NULL;
  643         }
  644         ZONE_LOCK(zone);
  645         bucket_cache_drain(zone);
  646         ZONE_UNLOCK(zone);
  647 }
  648 
  649 /*
  650  * Drain the cached buckets from a zone.  Expects a locked zone on entry.
  651  */
  652 static void
  653 bucket_cache_drain(uma_zone_t zone)
  654 {
  655         uma_bucket_t bucket;
  656 
  657         /*
  658          * Drain the bucket queues and free the buckets, we just keep two per
  659          * cpu (alloc/free).
  660          */
  661         while ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
  662                 LIST_REMOVE(bucket, ub_link);
  663                 ZONE_UNLOCK(zone);
  664                 bucket_drain(zone, bucket);
  665                 bucket_free(bucket);
  666                 ZONE_LOCK(zone);
  667         }
  668 
  669         /* Now we do the free queue.. */
  670         while ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
  671                 LIST_REMOVE(bucket, ub_link);
  672                 bucket_free(bucket);
  673         }
  674 }
  675 
  676 /*
  677  * Frees pages from a zone back to the system.  This is done on demand from
  678  * the pageout daemon.
  679  *
  680  * Arguments:
  681  *      zone  The zone to free pages from
  682  *       all  Should we drain all items?
  683  *
  684  * Returns:
  685  *      Nothing.
  686  */
  687 void
  688 zone_drain(uma_zone_t zone)
  689 {
  690         struct slabhead freeslabs = { 0 };
  691         uma_keg_t keg;
  692         uma_slab_t slab;
  693         uma_slab_t n;
  694         u_int8_t flags;
  695         u_int8_t *mem;
  696         int i;
  697 
  698         keg = zone->uz_keg;
  699 
  700         /*
  701          * We don't want to take pages from statically allocated zones at this
  702          * time
  703          */
  704         if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
  705                 return;
  706 
  707         ZONE_LOCK(zone);
  708 
  709 #ifdef UMA_DEBUG
  710         printf("%s free items: %u\n", zone->uz_name, keg->uk_free);
  711 #endif
  712         bucket_cache_drain(zone);
  713         if (keg->uk_free == 0)
  714                 goto finished;
  715 
  716         slab = LIST_FIRST(&keg->uk_free_slab);
  717         while (slab) {
  718                 n = LIST_NEXT(slab, us_link);
  719 
  720                 /* We have no where to free these to */
  721                 if (slab->us_flags & UMA_SLAB_BOOT) {
  722                         slab = n;
  723                         continue;
  724                 }
  725 
  726                 LIST_REMOVE(slab, us_link);
  727                 keg->uk_pages -= keg->uk_ppera;
  728                 keg->uk_free -= keg->uk_ipers;
  729 
  730                 if (keg->uk_flags & UMA_ZONE_HASH)
  731                         UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
  732 
  733                 SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
  734 
  735                 slab = n;
  736         }
  737 finished:
  738         ZONE_UNLOCK(zone);
  739 
  740         while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
  741                 SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
  742                 if (keg->uk_fini)
  743                         for (i = 0; i < keg->uk_ipers; i++)
  744                                 keg->uk_fini(
  745                                     slab->us_data + (keg->uk_rsize * i),
  746                                     keg->uk_size);
  747                 flags = slab->us_flags;
  748                 mem = slab->us_data;
  749 
  750                 if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
  751                     (keg->uk_flags & UMA_ZONE_REFCNT)) {
  752                         vm_object_t obj;
  753 
  754                         if (flags & UMA_SLAB_KMEM)
  755                                 obj = kmem_object;
  756                         else
  757                                 obj = NULL;
  758                         for (i = 0; i < keg->uk_ppera; i++)
  759                                 vsetobj((vm_offset_t)mem + (i * PAGE_SIZE),
  760                                     obj);
  761                 }
  762                 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
  763                         uma_zfree_internal(keg->uk_slabzone, slab, NULL,
  764                             SKIP_NONE, ZFREE_STATFREE);
  765 #ifdef UMA_DEBUG
  766                 printf("%s: Returning %d bytes.\n",
  767                     zone->uz_name, UMA_SLAB_SIZE * keg->uk_ppera);
  768 #endif
  769                 keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera, flags);
  770         }
  771 }
  772 
  773 /*
  774  * Allocate a new slab for a zone.  This does not insert the slab onto a list.
  775  *
  776  * Arguments:
  777  *      zone  The zone to allocate slabs for
  778  *      wait  Shall we wait?
  779  *
  780  * Returns:
  781  *      The slab that was allocated or NULL if there is no memory and the
  782  *      caller specified M_NOWAIT.
  783  */
  784 static uma_slab_t
  785 slab_zalloc(uma_zone_t zone, int wait)
  786 {
  787         uma_slabrefcnt_t slabref;
  788         uma_slab_t slab;
  789         uma_keg_t keg;
  790         u_int8_t *mem;
  791         u_int8_t flags;
  792         int i;
  793 
  794         slab = NULL;
  795         keg = zone->uz_keg;
  796 
  797 #ifdef UMA_DEBUG
  798         printf("slab_zalloc:  Allocating a new slab for %s\n", zone->uz_name);
  799 #endif
  800         ZONE_UNLOCK(zone);
  801 
  802         if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
  803                 slab = uma_zalloc_internal(keg->uk_slabzone, NULL, wait);
  804                 if (slab == NULL) {
  805                         ZONE_LOCK(zone);
  806                         return NULL;
  807                 }
  808         }
  809 
  810         /*
  811          * This reproduces the old vm_zone behavior of zero filling pages the
  812          * first time they are added to a zone.
  813          *
  814          * Malloced items are zeroed in uma_zalloc.
  815          */
  816 
  817         if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
  818                 wait |= M_ZERO;
  819         else
  820                 wait &= ~M_ZERO;
  821 
  822         mem = keg->uk_allocf(zone, keg->uk_ppera * UMA_SLAB_SIZE,
  823             &flags, wait);
  824         if (mem == NULL) {
  825                 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
  826                         uma_zfree_internal(keg->uk_slabzone, slab, NULL,
  827                             SKIP_NONE, ZFREE_STATFREE);
  828                 ZONE_LOCK(zone);
  829                 return (NULL);
  830         }
  831 
  832         /* Point the slab into the allocated memory */
  833         if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
  834                 slab = (uma_slab_t )(mem + keg->uk_pgoff);
  835 
  836         if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
  837             (keg->uk_flags & UMA_ZONE_REFCNT))
  838                 for (i = 0; i < keg->uk_ppera; i++)
  839                         vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
  840 
  841         slab->us_keg = keg;
  842         slab->us_data = mem;
  843         slab->us_freecount = keg->uk_ipers;
  844         slab->us_firstfree = 0;
  845         slab->us_flags = flags;
  846 
  847         if (keg->uk_flags & UMA_ZONE_REFCNT) {
  848                 slabref = (uma_slabrefcnt_t)slab;
  849                 for (i = 0; i < keg->uk_ipers; i++) {
  850                         slabref->us_freelist[i].us_refcnt = 0;
  851                         slabref->us_freelist[i].us_item = i+1;
  852                 }
  853         } else {
  854                 for (i = 0; i < keg->uk_ipers; i++)
  855                         slab->us_freelist[i].us_item = i+1;
  856         }
  857 
  858         if (keg->uk_init != NULL) {
  859                 for (i = 0; i < keg->uk_ipers; i++)
  860                         if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
  861                             keg->uk_size, wait) != 0)
  862                                 break;
  863                 if (i != keg->uk_ipers) {
  864                         if (keg->uk_fini != NULL) {
  865                                 for (i--; i > -1; i--)
  866                                         keg->uk_fini(slab->us_data +
  867                                             (keg->uk_rsize * i),
  868                                             keg->uk_size);
  869                         }
  870                         if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
  871                             (keg->uk_flags & UMA_ZONE_REFCNT)) {
  872                                 vm_object_t obj;
  873 
  874                                 if (flags & UMA_SLAB_KMEM)
  875                                         obj = kmem_object;
  876                                 else
  877                                         obj = NULL;
  878                                 for (i = 0; i < keg->uk_ppera; i++)
  879                                         vsetobj((vm_offset_t)mem +
  880                                             (i * PAGE_SIZE), obj);
  881                         }
  882                         if (keg->uk_flags & UMA_ZONE_OFFPAGE)
  883                                 uma_zfree_internal(keg->uk_slabzone, slab,
  884                                     NULL, SKIP_NONE, ZFREE_STATFREE);
  885                         keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera,
  886                             flags);
  887                         ZONE_LOCK(zone);
  888                         return (NULL);
  889                 }
  890         }
  891         ZONE_LOCK(zone);
  892 
  893         if (keg->uk_flags & UMA_ZONE_HASH)
  894                 UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
  895 
  896         keg->uk_pages += keg->uk_ppera;
  897         keg->uk_free += keg->uk_ipers;
  898 
  899         return (slab);
  900 }
  901 
  902 /*
  903  * This function is intended to be used early on in place of page_alloc() so
  904  * that we may use the boot time page cache to satisfy allocations before
  905  * the VM is ready.
  906  */
  907 static void *
  908 startup_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
  909 {
  910         uma_keg_t keg;
  911         uma_slab_t tmps;
  912 
  913         keg = zone->uz_keg;
  914 
  915         /*
  916          * Check our small startup cache to see if it has pages remaining.
  917          */
  918         mtx_lock(&uma_boot_pages_mtx);
  919         if ((tmps = LIST_FIRST(&uma_boot_pages)) != NULL) {
  920                 LIST_REMOVE(tmps, us_link);
  921                 mtx_unlock(&uma_boot_pages_mtx);
  922                 *pflag = tmps->us_flags;
  923                 return (tmps->us_data);
  924         }
  925         mtx_unlock(&uma_boot_pages_mtx);
  926         if (booted == 0)
  927                 panic("UMA: Increase vm.boot_pages");
  928         /*
  929          * Now that we've booted reset these users to their real allocator.
  930          */
  931 #ifdef UMA_MD_SMALL_ALLOC
  932         keg->uk_allocf = uma_small_alloc;
  933 #else
  934         keg->uk_allocf = page_alloc;
  935 #endif
  936         return keg->uk_allocf(zone, bytes, pflag, wait);
  937 }
  938 
  939 /*
  940  * Allocates a number of pages from the system
  941  *
  942  * Arguments:
  943  *      zone  Unused
  944  *      bytes  The number of bytes requested
  945  *      wait  Shall we wait?
  946  *
  947  * Returns:
  948  *      A pointer to the alloced memory or possibly
  949  *      NULL if M_NOWAIT is set.
  950  */
  951 static void *
  952 page_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
  953 {
  954         void *p;        /* Returned page */
  955 
  956         *pflag = UMA_SLAB_KMEM;
  957         p = (void *) kmem_malloc(kmem_map, bytes, wait);
  958 
  959         return (p);
  960 }
  961 
  962 /*
  963  * Allocates a number of pages from within an object
  964  *
  965  * Arguments:
  966  *      zone   Unused
  967  *      bytes  The number of bytes requested
  968  *      wait   Shall we wait?
  969  *
  970  * Returns:
  971  *      A pointer to the alloced memory or possibly
  972  *      NULL if M_NOWAIT is set.
  973  */
  974 static void *
  975 obj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
  976 {
  977         vm_object_t object;
  978         vm_offset_t retkva, zkva;
  979         vm_page_t p;
  980         int pages, startpages;
  981 
  982         object = zone->uz_keg->uk_obj;
  983         retkva = 0;
  984 
  985         /*
  986          * This looks a little weird since we're getting one page at a time.
  987          */
  988         VM_OBJECT_LOCK(object);
  989         p = TAILQ_LAST(&object->memq, pglist);
  990         pages = p != NULL ? p->pindex + 1 : 0;
  991         startpages = pages;
  992         zkva = zone->uz_keg->uk_kva + pages * PAGE_SIZE;
  993         for (; bytes > 0; bytes -= PAGE_SIZE) {
  994                 p = vm_page_alloc(object, pages,
  995                     VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED);
  996                 if (p == NULL) {
  997                         if (pages != startpages)
  998                                 pmap_qremove(retkva, pages - startpages);
  999                         while (pages != startpages) {
 1000                                 pages--;
 1001                                 p = TAILQ_LAST(&object->memq, pglist);
 1002                                 vm_page_lock_queues();
 1003                                 vm_page_unwire(p, 0);
 1004                                 vm_page_free(p);
 1005                                 vm_page_unlock_queues();
 1006                         }
 1007                         retkva = 0;
 1008                         goto done;
 1009                 }
 1010                 pmap_qenter(zkva, &p, 1);
 1011                 if (retkva == 0)
 1012                         retkva = zkva;
 1013                 zkva += PAGE_SIZE;
 1014                 pages += 1;
 1015         }
 1016 done:
 1017         VM_OBJECT_UNLOCK(object);
 1018         *flags = UMA_SLAB_PRIV;
 1019 
 1020         return ((void *)retkva);
 1021 }
 1022 
 1023 /*
 1024  * Frees a number of pages to the system
 1025  *
 1026  * Arguments:
 1027  *      mem   A pointer to the memory to be freed
 1028  *      size  The size of the memory being freed
 1029  *      flags The original p->us_flags field
 1030  *
 1031  * Returns:
 1032  *      Nothing
 1033  */
 1034 static void
 1035 page_free(void *mem, int size, u_int8_t flags)
 1036 {
 1037         vm_map_t map;
 1038 
 1039         if (flags & UMA_SLAB_KMEM)
 1040                 map = kmem_map;
 1041         else
 1042                 panic("UMA: page_free used with invalid flags %d\n", flags);
 1043 
 1044         kmem_free(map, (vm_offset_t)mem, size);
 1045 }
 1046 
 1047 /*
 1048  * Zero fill initializer
 1049  *
 1050  * Arguments/Returns follow uma_init specifications
 1051  */
 1052 static int
 1053 zero_init(void *mem, int size, int flags)
 1054 {
 1055         bzero(mem, size);
 1056         return (0);
 1057 }
 1058 
 1059 /*
 1060  * Finish creating a small uma zone.  This calculates ipers, and the zone size.
 1061  *
 1062  * Arguments
 1063  *      zone  The zone we should initialize
 1064  *
 1065  * Returns
 1066  *      Nothing
 1067  */
 1068 static void
 1069 zone_small_init(uma_zone_t zone)
 1070 {
 1071         uma_keg_t keg;
 1072         u_int rsize;
 1073         u_int memused;
 1074         u_int wastedspace;
 1075         u_int shsize;
 1076 
 1077         keg = zone->uz_keg;
 1078         KASSERT(keg != NULL, ("Keg is null in zone_small_init"));
 1079         rsize = keg->uk_size;
 1080 
 1081         if (rsize < UMA_SMALLEST_UNIT)
 1082                 rsize = UMA_SMALLEST_UNIT;
 1083         if (rsize & keg->uk_align)
 1084                 rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
 1085 
 1086         keg->uk_rsize = rsize;
 1087         keg->uk_ppera = 1;
 1088 
 1089         if (keg->uk_flags & UMA_ZONE_REFCNT) {
 1090                 rsize += UMA_FRITMREF_SZ;       /* linkage & refcnt */
 1091                 shsize = sizeof(struct uma_slab_refcnt);
 1092         } else {
 1093                 rsize += UMA_FRITM_SZ;  /* Account for linkage */
 1094                 shsize = sizeof(struct uma_slab);
 1095         }
 1096 
 1097         keg->uk_ipers = (UMA_SLAB_SIZE - shsize) / rsize;
 1098         KASSERT(keg->uk_ipers != 0, ("zone_small_init: ipers is 0"));
 1099         memused = keg->uk_ipers * rsize + shsize;
 1100         wastedspace = UMA_SLAB_SIZE - memused;
 1101 
 1102         /*
 1103          * We can't do OFFPAGE if we're internal or if we've been
 1104          * asked to not go to the VM for buckets.  If we do this we
 1105          * may end up going to the VM (kmem_map) for slabs which we
 1106          * do not want to do if we're UMA_ZFLAG_CACHEONLY as a
 1107          * result of UMA_ZONE_VM, which clearly forbids it.
 1108          */
 1109         if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
 1110             (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
 1111                 return;
 1112 
 1113         if ((wastedspace >= UMA_MAX_WASTE) &&
 1114             (keg->uk_ipers < (UMA_SLAB_SIZE / keg->uk_rsize))) {
 1115                 keg->uk_ipers = UMA_SLAB_SIZE / keg->uk_rsize;
 1116                 KASSERT(keg->uk_ipers <= 255,
 1117                     ("zone_small_init: keg->uk_ipers too high!"));
 1118 #ifdef UMA_DEBUG
 1119                 printf("UMA decided we need offpage slab headers for "
 1120                     "zone: %s, calculated wastedspace = %d, "
 1121                     "maximum wasted space allowed = %d, "
 1122                     "calculated ipers = %d, "
 1123                     "new wasted space = %d\n", zone->uz_name, wastedspace,
 1124                     UMA_MAX_WASTE, keg->uk_ipers,
 1125                     UMA_SLAB_SIZE - keg->uk_ipers * keg->uk_rsize);
 1126 #endif
 1127                 keg->uk_flags |= UMA_ZONE_OFFPAGE;
 1128                 if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
 1129                         keg->uk_flags |= UMA_ZONE_HASH;
 1130         }
 1131 }
 1132 
 1133 /*
 1134  * Finish creating a large (> UMA_SLAB_SIZE) uma zone.  Just give in and do
 1135  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
 1136  * more complicated.
 1137  *
 1138  * Arguments
 1139  *      zone  The zone we should initialize
 1140  *
 1141  * Returns
 1142  *      Nothing
 1143  */
 1144 static void
 1145 zone_large_init(uma_zone_t zone)
 1146 {
 1147         uma_keg_t keg;
 1148         int pages;
 1149 
 1150         keg = zone->uz_keg;
 1151 
 1152         KASSERT(keg != NULL, ("Keg is null in zone_large_init"));
 1153         KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
 1154             ("zone_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY zone"));
 1155 
 1156         pages = keg->uk_size / UMA_SLAB_SIZE;
 1157 
 1158         /* Account for remainder */
 1159         if ((pages * UMA_SLAB_SIZE) < keg->uk_size)
 1160                 pages++;
 1161 
 1162         keg->uk_ppera = pages;
 1163         keg->uk_ipers = 1;
 1164 
 1165         keg->uk_flags |= UMA_ZONE_OFFPAGE;
 1166         if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
 1167                 keg->uk_flags |= UMA_ZONE_HASH;
 1168 
 1169         keg->uk_rsize = keg->uk_size;
 1170 }
 1171 
 1172 /*
 1173  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
 1174  * the keg onto the global keg list.
 1175  *
 1176  * Arguments/Returns follow uma_ctor specifications
 1177  *      udata  Actually uma_kctor_args
 1178  */
 1179 static int
 1180 keg_ctor(void *mem, int size, void *udata, int flags)
 1181 {
 1182         struct uma_kctor_args *arg = udata;
 1183         uma_keg_t keg = mem;
 1184         uma_zone_t zone;
 1185 
 1186         bzero(keg, size);
 1187         keg->uk_size = arg->size;
 1188         keg->uk_init = arg->uminit;
 1189         keg->uk_fini = arg->fini;
 1190         keg->uk_align = arg->align;
 1191         keg->uk_free = 0;
 1192         keg->uk_pages = 0;
 1193         keg->uk_flags = arg->flags;
 1194         keg->uk_allocf = page_alloc;
 1195         keg->uk_freef = page_free;
 1196         keg->uk_recurse = 0;
 1197         keg->uk_slabzone = NULL;
 1198 
 1199         /*
 1200          * The master zone is passed to us at keg-creation time.
 1201          */
 1202         zone = arg->zone;
 1203         zone->uz_keg = keg;
 1204 
 1205         if (arg->flags & UMA_ZONE_VM)
 1206                 keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
 1207 
 1208         if (arg->flags & UMA_ZONE_ZINIT)
 1209                 keg->uk_init = zero_init;
 1210 
 1211         /*
 1212          * The +UMA_FRITM_SZ added to uk_size is to account for the
 1213          * linkage that is added to the size in zone_small_init().  If
 1214          * we don't account for this here then we may end up in
 1215          * zone_small_init() with a calculated 'ipers' of 0.
 1216          */
 1217         if (keg->uk_flags & UMA_ZONE_REFCNT) {
 1218                 if ((keg->uk_size+UMA_FRITMREF_SZ) >
 1219                     (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)))
 1220                         zone_large_init(zone);
 1221                 else
 1222                         zone_small_init(zone);
 1223         } else {
 1224                 if ((keg->uk_size+UMA_FRITM_SZ) >
 1225                     (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
 1226                         zone_large_init(zone);
 1227                 else
 1228                         zone_small_init(zone);
 1229         }
 1230 
 1231         if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
 1232                 if (keg->uk_flags & UMA_ZONE_REFCNT)
 1233                         keg->uk_slabzone = slabrefzone;
 1234                 else
 1235                         keg->uk_slabzone = slabzone;
 1236         }
 1237 
 1238         /*
 1239          * If we haven't booted yet we need allocations to go through the
 1240          * startup cache until the vm is ready.
 1241          */
 1242         if (keg->uk_ppera == 1) {
 1243 #ifdef UMA_MD_SMALL_ALLOC
 1244                 keg->uk_allocf = uma_small_alloc;
 1245                 keg->uk_freef = uma_small_free;
 1246 #endif
 1247                 if (booted == 0)
 1248                         keg->uk_allocf = startup_alloc;
 1249         }
 1250 
 1251         /*
 1252          * Initialize keg's lock (shared among zones) through
 1253          * Master zone
 1254          */
 1255         zone->uz_lock = &keg->uk_lock;
 1256         if (arg->flags & UMA_ZONE_MTXCLASS)
 1257                 ZONE_LOCK_INIT(zone, 1);
 1258         else
 1259                 ZONE_LOCK_INIT(zone, 0);
 1260 
 1261         /*
 1262          * If we're putting the slab header in the actual page we need to
 1263          * figure out where in each page it goes.  This calculates a right
 1264          * justified offset into the memory on an ALIGN_PTR boundary.
 1265          */
 1266         if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
 1267                 u_int totsize;
 1268 
 1269                 /* Size of the slab struct and free list */
 1270                 if (keg->uk_flags & UMA_ZONE_REFCNT)
 1271                         totsize = sizeof(struct uma_slab_refcnt) +
 1272                             keg->uk_ipers * UMA_FRITMREF_SZ;
 1273                 else
 1274                         totsize = sizeof(struct uma_slab) +
 1275                             keg->uk_ipers * UMA_FRITM_SZ;
 1276 
 1277                 if (totsize & UMA_ALIGN_PTR)
 1278                         totsize = (totsize & ~UMA_ALIGN_PTR) +
 1279                             (UMA_ALIGN_PTR + 1);
 1280                 keg->uk_pgoff = UMA_SLAB_SIZE - totsize;
 1281 
 1282                 if (keg->uk_flags & UMA_ZONE_REFCNT)
 1283                         totsize = keg->uk_pgoff + sizeof(struct uma_slab_refcnt)
 1284                             + keg->uk_ipers * UMA_FRITMREF_SZ;
 1285                 else
 1286                         totsize = keg->uk_pgoff + sizeof(struct uma_slab)
 1287                             + keg->uk_ipers * UMA_FRITM_SZ;
 1288 
 1289                 /*
 1290                  * The only way the following is possible is if with our
 1291                  * UMA_ALIGN_PTR adjustments we are now bigger than
 1292                  * UMA_SLAB_SIZE.  I haven't checked whether this is
 1293                  * mathematically possible for all cases, so we make
 1294                  * sure here anyway.
 1295                  */
 1296                 if (totsize > UMA_SLAB_SIZE) {
 1297                         printf("zone %s ipers %d rsize %d size %d\n",
 1298                             zone->uz_name, keg->uk_ipers, keg->uk_rsize,
 1299                             keg->uk_size);
 1300                         panic("UMA slab won't fit.\n");
 1301                 }
 1302         }
 1303 
 1304         if (keg->uk_flags & UMA_ZONE_HASH)
 1305                 hash_alloc(&keg->uk_hash);
 1306 
 1307 #ifdef UMA_DEBUG
 1308         printf("%s(%p) size = %d ipers = %d ppera = %d pgoff = %d\n",
 1309             zone->uz_name, zone,
 1310             keg->uk_size, keg->uk_ipers,
 1311             keg->uk_ppera, keg->uk_pgoff);
 1312 #endif
 1313 
 1314         LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
 1315 
 1316         mtx_lock(&uma_mtx);
 1317         LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
 1318         mtx_unlock(&uma_mtx);
 1319         return (0);
 1320 }
 1321 
 1322 /*
 1323  * Zone header ctor.  This initializes all fields, locks, etc.
 1324  *
 1325  * Arguments/Returns follow uma_ctor specifications
 1326  *      udata  Actually uma_zctor_args
 1327  */
 1328 
 1329 static int
 1330 zone_ctor(void *mem, int size, void *udata, int flags)
 1331 {
 1332         struct uma_zctor_args *arg = udata;
 1333         uma_zone_t zone = mem;
 1334         uma_zone_t z;
 1335         uma_keg_t keg;
 1336 
 1337         bzero(zone, size);
 1338         zone->uz_name = arg->name;
 1339         zone->uz_ctor = arg->ctor;
 1340         zone->uz_dtor = arg->dtor;
 1341         zone->uz_init = NULL;
 1342         zone->uz_fini = NULL;
 1343         zone->uz_allocs = 0;
 1344         zone->uz_frees = 0;
 1345         zone->uz_fails = 0;
 1346         zone->uz_fills = zone->uz_count = 0;
 1347 
 1348         if (arg->flags & UMA_ZONE_SECONDARY) {
 1349                 KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
 1350                 keg = arg->keg;
 1351                 zone->uz_keg = keg;
 1352                 zone->uz_init = arg->uminit;
 1353                 zone->uz_fini = arg->fini;
 1354                 zone->uz_lock = &keg->uk_lock;
 1355                 mtx_lock(&uma_mtx);
 1356                 ZONE_LOCK(zone);
 1357                 keg->uk_flags |= UMA_ZONE_SECONDARY;
 1358                 LIST_FOREACH(z, &keg->uk_zones, uz_link) {
 1359                         if (LIST_NEXT(z, uz_link) == NULL) {
 1360                                 LIST_INSERT_AFTER(z, zone, uz_link);
 1361                                 break;
 1362                         }
 1363                 }
 1364                 ZONE_UNLOCK(zone);
 1365                 mtx_unlock(&uma_mtx);
 1366         } else if (arg->keg == NULL) {
 1367                 if (uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
 1368                     arg->align, arg->flags) == NULL)
 1369                         return (ENOMEM);
 1370         } else {
 1371                 struct uma_kctor_args karg;
 1372                 int error;
 1373 
 1374                 /* We should only be here from uma_startup() */
 1375                 karg.size = arg->size;
 1376                 karg.uminit = arg->uminit;
 1377                 karg.fini = arg->fini;
 1378                 karg.align = arg->align;
 1379                 karg.flags = arg->flags;
 1380                 karg.zone = zone;
 1381                 error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
 1382                     flags);
 1383                 if (error)
 1384                         return (error);
 1385         }
 1386         keg = zone->uz_keg;
 1387         zone->uz_lock = &keg->uk_lock;
 1388 
 1389         /*
 1390          * Some internal zones don't have room allocated for the per cpu
 1391          * caches.  If we're internal, bail out here.
 1392          */
 1393         if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
 1394                 KASSERT((keg->uk_flags & UMA_ZONE_SECONDARY) == 0,
 1395                     ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
 1396                 return (0);
 1397         }
 1398 
 1399         if (keg->uk_flags & UMA_ZONE_MAXBUCKET)
 1400                 zone->uz_count = BUCKET_MAX;
 1401         else if (keg->uk_ipers <= BUCKET_MAX)
 1402                 zone->uz_count = keg->uk_ipers;
 1403         else
 1404                 zone->uz_count = BUCKET_MAX;
 1405         return (0);
 1406 }
 1407 
 1408 /*
 1409  * Keg header dtor.  This frees all data, destroys locks, frees the hash
 1410  * table and removes the keg from the global list.
 1411  *
 1412  * Arguments/Returns follow uma_dtor specifications
 1413  *      udata  unused
 1414  */
 1415 static void
 1416 keg_dtor(void *arg, int size, void *udata)
 1417 {
 1418         uma_keg_t keg;
 1419 
 1420         keg = (uma_keg_t)arg;
 1421         mtx_lock(&keg->uk_lock);
 1422         if (keg->uk_free != 0) {
 1423                 printf("Freed UMA keg was not empty (%d items). "
 1424                     " Lost %d pages of memory.\n",
 1425                     keg->uk_free, keg->uk_pages);
 1426         }
 1427         mtx_unlock(&keg->uk_lock);
 1428 
 1429         if (keg->uk_flags & UMA_ZONE_HASH)
 1430                 hash_free(&keg->uk_hash);
 1431 
 1432         mtx_destroy(&keg->uk_lock);
 1433 }
 1434 
 1435 /*
 1436  * Zone header dtor.
 1437  *
 1438  * Arguments/Returns follow uma_dtor specifications
 1439  *      udata  unused
 1440  */
 1441 static void
 1442 zone_dtor(void *arg, int size, void *udata)
 1443 {
 1444         uma_zone_t zone;
 1445         uma_keg_t keg;
 1446 
 1447         zone = (uma_zone_t)arg;
 1448         keg = zone->uz_keg;
 1449 
 1450         if (!(keg->uk_flags & UMA_ZFLAG_INTERNAL))
 1451                 cache_drain(zone);
 1452 
 1453         mtx_lock(&uma_mtx);
 1454         zone_drain(zone);
 1455         if (keg->uk_flags & UMA_ZONE_SECONDARY) {
 1456                 LIST_REMOVE(zone, uz_link);
 1457                 /*
 1458                  * XXX there are some races here where
 1459                  * the zone can be drained but zone lock
 1460                  * released and then refilled before we
 1461                  * remove it... we dont care for now
 1462                  */
 1463                 ZONE_LOCK(zone);
 1464                 if (LIST_EMPTY(&keg->uk_zones))
 1465                         keg->uk_flags &= ~UMA_ZONE_SECONDARY;
 1466                 ZONE_UNLOCK(zone);
 1467                 mtx_unlock(&uma_mtx);
 1468         } else {
 1469                 LIST_REMOVE(keg, uk_link);
 1470                 LIST_REMOVE(zone, uz_link);
 1471                 mtx_unlock(&uma_mtx);
 1472                 uma_zfree_internal(kegs, keg, NULL, SKIP_NONE,
 1473                     ZFREE_STATFREE);
 1474         }
 1475         zone->uz_keg = NULL;
 1476 }
 1477 
 1478 /*
 1479  * Traverses every zone in the system and calls a callback
 1480  *
 1481  * Arguments:
 1482  *      zfunc  A pointer to a function which accepts a zone
 1483  *              as an argument.
 1484  *
 1485  * Returns:
 1486  *      Nothing
 1487  */
 1488 static void
 1489 zone_foreach(void (*zfunc)(uma_zone_t))
 1490 {
 1491         uma_keg_t keg;
 1492         uma_zone_t zone;
 1493 
 1494         mtx_lock(&uma_mtx);
 1495         LIST_FOREACH(keg, &uma_kegs, uk_link) {
 1496                 LIST_FOREACH(zone, &keg->uk_zones, uz_link)
 1497                         zfunc(zone);
 1498         }
 1499         mtx_unlock(&uma_mtx);
 1500 }
 1501 
 1502 /* Public functions */
 1503 /* See uma.h */
 1504 void
 1505 uma_startup(void *bootmem, int boot_pages)
 1506 {
 1507         struct uma_zctor_args args;
 1508         uma_slab_t slab;
 1509         u_int slabsize;
 1510         u_int objsize, totsize, wsize;
 1511         int i;
 1512 
 1513 #ifdef UMA_DEBUG
 1514         printf("Creating uma keg headers zone and keg.\n");
 1515 #endif
 1516         mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
 1517 
 1518         /*
 1519          * Figure out the maximum number of items-per-slab we'll have if
 1520          * we're using the OFFPAGE slab header to track free items, given
 1521          * all possible object sizes and the maximum desired wastage
 1522          * (UMA_MAX_WASTE).
 1523          *
 1524          * We iterate until we find an object size for
 1525          * which the calculated wastage in zone_small_init() will be
 1526          * enough to warrant OFFPAGE.  Since wastedspace versus objsize
 1527          * is an overall increasing see-saw function, we find the smallest
 1528          * objsize such that the wastage is always acceptable for objects
 1529          * with that objsize or smaller.  Since a smaller objsize always
 1530          * generates a larger possible uma_max_ipers, we use this computed
 1531          * objsize to calculate the largest ipers possible.  Since the
 1532          * ipers calculated for OFFPAGE slab headers is always larger than
 1533          * the ipers initially calculated in zone_small_init(), we use
 1534          * the former's equation (UMA_SLAB_SIZE / keg->uk_rsize) to
 1535          * obtain the maximum ipers possible for offpage slab headers.
 1536          *
 1537          * It should be noted that ipers versus objsize is an inversly
 1538          * proportional function which drops off rather quickly so as
 1539          * long as our UMA_MAX_WASTE is such that the objsize we calculate
 1540          * falls into the portion of the inverse relation AFTER the steep
 1541          * falloff, then uma_max_ipers shouldn't be too high (~10 on i386).
 1542          *
 1543          * Note that we have 8-bits (1 byte) to use as a freelist index
 1544          * inside the actual slab header itself and this is enough to
 1545          * accomodate us.  In the worst case, a UMA_SMALLEST_UNIT sized
 1546          * object with offpage slab header would have ipers =
 1547          * UMA_SLAB_SIZE / UMA_SMALLEST_UNIT (currently = 256), which is
 1548          * 1 greater than what our byte-integer freelist index can
 1549          * accomodate, but we know that this situation never occurs as
 1550          * for UMA_SMALLEST_UNIT-sized objects, we will never calculate
 1551          * that we need to go to offpage slab headers.  Or, if we do,
 1552          * then we trap that condition below and panic in the INVARIANTS case.
 1553          */
 1554         wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab) - UMA_MAX_WASTE;
 1555         totsize = wsize;
 1556         objsize = UMA_SMALLEST_UNIT;
 1557         while (totsize >= wsize) {
 1558                 totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) /
 1559                     (objsize + UMA_FRITM_SZ);
 1560                 totsize *= (UMA_FRITM_SZ + objsize);
 1561                 objsize++;
 1562         }
 1563         if (objsize > UMA_SMALLEST_UNIT)
 1564                 objsize--;
 1565         uma_max_ipers = UMA_SLAB_SIZE / objsize;
 1566 
 1567         wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) - UMA_MAX_WASTE;
 1568         totsize = wsize;
 1569         objsize = UMA_SMALLEST_UNIT;
 1570         while (totsize >= wsize) {
 1571                 totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)) /
 1572                     (objsize + UMA_FRITMREF_SZ);
 1573                 totsize *= (UMA_FRITMREF_SZ + objsize);
 1574                 objsize++;
 1575         }
 1576         if (objsize > UMA_SMALLEST_UNIT)
 1577                 objsize--;
 1578         uma_max_ipers_ref = UMA_SLAB_SIZE / objsize;
 1579 
 1580         KASSERT((uma_max_ipers_ref <= 255) && (uma_max_ipers <= 255),
 1581             ("uma_startup: calculated uma_max_ipers values too large!"));
 1582 
 1583 #ifdef UMA_DEBUG
 1584         printf("Calculated uma_max_ipers (for OFFPAGE) is %d\n", uma_max_ipers);
 1585         printf("Calculated uma_max_ipers_slab (for OFFPAGE) is %d\n",
 1586             uma_max_ipers_ref);
 1587 #endif
 1588 
 1589         /* "manually" create the initial zone */
 1590         args.name = "UMA Kegs";
 1591         args.size = sizeof(struct uma_keg);
 1592         args.ctor = keg_ctor;
 1593         args.dtor = keg_dtor;
 1594         args.uminit = zero_init;
 1595         args.fini = NULL;
 1596         args.keg = &masterkeg;
 1597         args.align = 32 - 1;
 1598         args.flags = UMA_ZFLAG_INTERNAL;
 1599         /* The initial zone has no Per cpu queues so it's smaller */
 1600         zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
 1601 
 1602 #ifdef UMA_DEBUG
 1603         printf("Filling boot free list.\n");
 1604 #endif
 1605         for (i = 0; i < boot_pages; i++) {
 1606                 slab = (uma_slab_t)((u_int8_t *)bootmem + (i * UMA_SLAB_SIZE));
 1607                 slab->us_data = (u_int8_t *)slab;
 1608                 slab->us_flags = UMA_SLAB_BOOT;
 1609                 LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
 1610         }
 1611         mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
 1612 
 1613 #ifdef UMA_DEBUG
 1614         printf("Creating uma zone headers zone and keg.\n");
 1615 #endif
 1616         args.name = "UMA Zones";
 1617         args.size = sizeof(struct uma_zone) +
 1618             (sizeof(struct uma_cache) * (mp_maxid + 1));
 1619         args.ctor = zone_ctor;
 1620         args.dtor = zone_dtor;
 1621         args.uminit = zero_init;
 1622         args.fini = NULL;
 1623         args.keg = NULL;
 1624         args.align = 32 - 1;
 1625         args.flags = UMA_ZFLAG_INTERNAL;
 1626         /* The initial zone has no Per cpu queues so it's smaller */
 1627         zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
 1628 
 1629 #ifdef UMA_DEBUG
 1630         printf("Initializing pcpu cache locks.\n");
 1631 #endif
 1632 #ifdef UMA_DEBUG
 1633         printf("Creating slab and hash zones.\n");
 1634 #endif
 1635 
 1636         /*
 1637          * This is the max number of free list items we'll have with
 1638          * offpage slabs.
 1639          */
 1640         slabsize = uma_max_ipers * UMA_FRITM_SZ;
 1641         slabsize += sizeof(struct uma_slab);
 1642 
 1643         /* Now make a zone for slab headers */
 1644         slabzone = uma_zcreate("UMA Slabs",
 1645                                 slabsize,
 1646                                 NULL, NULL, NULL, NULL,
 1647                                 UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
 1648 
 1649         /*
 1650          * We also create a zone for the bigger slabs with reference
 1651          * counts in them, to accomodate UMA_ZONE_REFCNT zones.
 1652          */
 1653         slabsize = uma_max_ipers_ref * UMA_FRITMREF_SZ;
 1654         slabsize += sizeof(struct uma_slab_refcnt);
 1655         slabrefzone = uma_zcreate("UMA RCntSlabs",
 1656                                   slabsize,
 1657                                   NULL, NULL, NULL, NULL,
 1658                                   UMA_ALIGN_PTR,
 1659                                   UMA_ZFLAG_INTERNAL);
 1660 
 1661         hashzone = uma_zcreate("UMA Hash",
 1662             sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
 1663             NULL, NULL, NULL, NULL,
 1664             UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
 1665 
 1666         bucket_init();
 1667 
 1668 #ifdef UMA_MD_SMALL_ALLOC
 1669         booted = 1;
 1670 #endif
 1671 
 1672 #ifdef UMA_DEBUG
 1673         printf("UMA startup complete.\n");
 1674 #endif
 1675 }
 1676 
 1677 /* see uma.h */
 1678 void
 1679 uma_startup2(void)
 1680 {
 1681         booted = 1;
 1682         bucket_enable();
 1683 #ifdef UMA_DEBUG
 1684         printf("UMA startup2 complete.\n");
 1685 #endif
 1686 }
 1687 
 1688 /*
 1689  * Initialize our callout handle
 1690  *
 1691  */
 1692 
 1693 static void
 1694 uma_startup3(void)
 1695 {
 1696 #ifdef UMA_DEBUG
 1697         printf("Starting callout.\n");
 1698 #endif
 1699         callout_init(&uma_callout, CALLOUT_MPSAFE);
 1700         callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
 1701 #ifdef UMA_DEBUG
 1702         printf("UMA startup3 complete.\n");
 1703 #endif
 1704 }
 1705 
 1706 static uma_zone_t
 1707 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
 1708                 int align, u_int32_t flags)
 1709 {
 1710         struct uma_kctor_args args;
 1711 
 1712         args.size = size;
 1713         args.uminit = uminit;
 1714         args.fini = fini;
 1715         args.align = align;
 1716         args.flags = flags;
 1717         args.zone = zone;
 1718         return (uma_zalloc_internal(kegs, &args, M_WAITOK));
 1719 }
 1720 
 1721 /* See uma.h */
 1722 uma_zone_t
 1723 uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
 1724                 uma_init uminit, uma_fini fini, int align, u_int32_t flags)
 1725 
 1726 {
 1727         struct uma_zctor_args args;
 1728 
 1729         /* This stuff is essential for the zone ctor */
 1730         args.name = name;
 1731         args.size = size;
 1732         args.ctor = ctor;
 1733         args.dtor = dtor;
 1734         args.uminit = uminit;
 1735         args.fini = fini;
 1736         args.align = align;
 1737         args.flags = flags;
 1738         args.keg = NULL;
 1739 
 1740         return (uma_zalloc_internal(zones, &args, M_WAITOK));
 1741 }
 1742 
 1743 /* See uma.h */
 1744 uma_zone_t
 1745 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
 1746                     uma_init zinit, uma_fini zfini, uma_zone_t master)
 1747 {
 1748         struct uma_zctor_args args;
 1749 
 1750         args.name = name;
 1751         args.size = master->uz_keg->uk_size;
 1752         args.ctor = ctor;
 1753         args.dtor = dtor;
 1754         args.uminit = zinit;
 1755         args.fini = zfini;
 1756         args.align = master->uz_keg->uk_align;
 1757         args.flags = master->uz_keg->uk_flags | UMA_ZONE_SECONDARY;
 1758         args.keg = master->uz_keg;
 1759 
 1760         return (uma_zalloc_internal(zones, &args, M_WAITOK));
 1761 }
 1762 
 1763 /* See uma.h */
 1764 void
 1765 uma_zdestroy(uma_zone_t zone)
 1766 {
 1767 
 1768         uma_zfree_internal(zones, zone, NULL, SKIP_NONE, ZFREE_STATFREE);
 1769 }
 1770 
 1771 /* See uma.h */
 1772 void *
 1773 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
 1774 {
 1775         void *item;
 1776         uma_cache_t cache;
 1777         uma_bucket_t bucket;
 1778         int cpu;
 1779         int badness;
 1780 
 1781         /* This is the fast path allocation */
 1782 #ifdef UMA_DEBUG_ALLOC_1
 1783         printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
 1784 #endif
 1785         CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
 1786             zone->uz_name, flags);
 1787 
 1788         if (!(flags & M_NOWAIT)) {
 1789                 KASSERT(curthread->td_intr_nesting_level == 0,
 1790                    ("malloc(M_WAITOK) in interrupt context"));
 1791                 if (nosleepwithlocks) {
 1792 #ifdef WITNESS
 1793                         badness = WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
 1794                             NULL,
 1795                             "malloc(M_WAITOK) of \"%s\", forcing M_NOWAIT",
 1796                             zone->uz_name);
 1797 #else
 1798                         badness = 1;
 1799 #endif
 1800                 } else {
 1801                         badness = 0;
 1802 #ifdef WITNESS
 1803                         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
 1804                             "malloc(M_WAITOK) of \"%s\"", zone->uz_name);
 1805 #endif
 1806                 }
 1807                 if (badness) {
 1808                         flags &= ~M_WAITOK;
 1809                         flags |= M_NOWAIT;
 1810                 }
 1811         }
 1812 
 1813         /*
 1814          * If possible, allocate from the per-CPU cache.  There are two
 1815          * requirements for safe access to the per-CPU cache: (1) the thread
 1816          * accessing the cache must not be preempted or yield during access,
 1817          * and (2) the thread must not migrate CPUs without switching which
 1818          * cache it accesses.  We rely on a critical section to prevent
 1819          * preemption and migration.  We release the critical section in
 1820          * order to acquire the zone mutex if we are unable to allocate from
 1821          * the current cache; when we re-acquire the critical section, we
 1822          * must detect and handle migration if it has occurred.
 1823          */
 1824 zalloc_restart:
 1825         critical_enter();
 1826         cpu = curcpu;
 1827         cache = &zone->uz_cpu[cpu];
 1828 
 1829 zalloc_start:
 1830         bucket = cache->uc_allocbucket;
 1831 
 1832         if (bucket) {
 1833                 if (bucket->ub_cnt > 0) {
 1834                         bucket->ub_cnt--;
 1835                         item = bucket->ub_bucket[bucket->ub_cnt];
 1836 #ifdef INVARIANTS
 1837                         bucket->ub_bucket[bucket->ub_cnt] = NULL;
 1838 #endif
 1839                         KASSERT(item != NULL,
 1840                             ("uma_zalloc: Bucket pointer mangled."));
 1841                         cache->uc_allocs++;
 1842                         critical_exit();
 1843 #ifdef INVARIANTS
 1844                         ZONE_LOCK(zone);
 1845                         uma_dbg_alloc(zone, NULL, item);
 1846                         ZONE_UNLOCK(zone);
 1847 #endif
 1848                         if (zone->uz_ctor != NULL) {
 1849                                 if (zone->uz_ctor(item, zone->uz_keg->uk_size,
 1850                                     udata, flags) != 0) {
 1851                                         uma_zfree_internal(zone, item, udata,
 1852                                             SKIP_DTOR, ZFREE_STATFAIL |
 1853                                             ZFREE_STATFREE);
 1854                                         return (NULL);
 1855                                 }
 1856                         }
 1857                         if (flags & M_ZERO)
 1858                                 bzero(item, zone->uz_keg->uk_size);
 1859                         return (item);
 1860                 } else if (cache->uc_freebucket) {
 1861                         /*
 1862                          * We have run out of items in our allocbucket.
 1863                          * See if we can switch with our free bucket.
 1864                          */
 1865                         if (cache->uc_freebucket->ub_cnt > 0) {
 1866 #ifdef UMA_DEBUG_ALLOC
 1867                                 printf("uma_zalloc: Swapping empty with"
 1868                                     " alloc.\n");
 1869 #endif
 1870                                 bucket = cache->uc_freebucket;
 1871                                 cache->uc_freebucket = cache->uc_allocbucket;
 1872                                 cache->uc_allocbucket = bucket;
 1873 
 1874                                 goto zalloc_start;
 1875                         }
 1876                 }
 1877         }
 1878         /*
 1879          * Attempt to retrieve the item from the per-CPU cache has failed, so
 1880          * we must go back to the zone.  This requires the zone lock, so we
 1881          * must drop the critical section, then re-acquire it when we go back
 1882          * to the cache.  Since the critical section is released, we may be
 1883          * preempted or migrate.  As such, make sure not to maintain any
 1884          * thread-local state specific to the cache from prior to releasing
 1885          * the critical section.
 1886          */
 1887         critical_exit();
 1888         ZONE_LOCK(zone);
 1889         critical_enter();
 1890         cpu = curcpu;
 1891         cache = &zone->uz_cpu[cpu];
 1892         bucket = cache->uc_allocbucket;
 1893         if (bucket != NULL) {
 1894                 if (bucket->ub_cnt > 0) {
 1895                         ZONE_UNLOCK(zone);
 1896                         goto zalloc_start;
 1897                 }
 1898                 bucket = cache->uc_freebucket;
 1899                 if (bucket != NULL && bucket->ub_cnt > 0) {
 1900                         ZONE_UNLOCK(zone);
 1901                         goto zalloc_start;
 1902                 }
 1903         }
 1904 
 1905         /* Since we have locked the zone we may as well send back our stats */
 1906         zone->uz_allocs += cache->uc_allocs;
 1907         cache->uc_allocs = 0;
 1908         zone->uz_frees += cache->uc_frees;
 1909         cache->uc_frees = 0;
 1910 
 1911         /* Our old one is now a free bucket */
 1912         if (cache->uc_allocbucket) {
 1913                 KASSERT(cache->uc_allocbucket->ub_cnt == 0,
 1914                     ("uma_zalloc_arg: Freeing a non free bucket."));
 1915                 LIST_INSERT_HEAD(&zone->uz_free_bucket,
 1916                     cache->uc_allocbucket, ub_link);
 1917                 cache->uc_allocbucket = NULL;
 1918         }
 1919 
 1920         /* Check the free list for a new alloc bucket */
 1921         if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
 1922                 KASSERT(bucket->ub_cnt != 0,
 1923                     ("uma_zalloc_arg: Returning an empty bucket."));
 1924 
 1925                 LIST_REMOVE(bucket, ub_link);
 1926                 cache->uc_allocbucket = bucket;
 1927                 ZONE_UNLOCK(zone);
 1928                 goto zalloc_start;
 1929         }
 1930         /* We are no longer associated with this CPU. */
 1931         critical_exit();
 1932 
 1933         /* Bump up our uz_count so we get here less */
 1934         if (zone->uz_count < BUCKET_MAX)
 1935                 zone->uz_count++;
 1936 
 1937         /*
 1938          * Now lets just fill a bucket and put it on the free list.  If that
 1939          * works we'll restart the allocation from the begining.
 1940          */
 1941         if (uma_zalloc_bucket(zone, flags)) {
 1942                 ZONE_UNLOCK(zone);
 1943                 goto zalloc_restart;
 1944         }
 1945         ZONE_UNLOCK(zone);
 1946         /*
 1947          * We may not be able to get a bucket so return an actual item.
 1948          */
 1949 #ifdef UMA_DEBUG
 1950         printf("uma_zalloc_arg: Bucketzone returned NULL\n");
 1951 #endif
 1952 
 1953         return (uma_zalloc_internal(zone, udata, flags));
 1954 }
 1955 
 1956 static uma_slab_t
 1957 uma_zone_slab(uma_zone_t zone, int flags)
 1958 {
 1959         uma_slab_t slab;
 1960         uma_keg_t keg;
 1961 
 1962         keg = zone->uz_keg;
 1963 
 1964         /*
 1965          * This is to prevent us from recursively trying to allocate
 1966          * buckets.  The problem is that if an allocation forces us to
 1967          * grab a new bucket we will call page_alloc, which will go off
 1968          * and cause the vm to allocate vm_map_entries.  If we need new
 1969          * buckets there too we will recurse in kmem_alloc and bad
 1970          * things happen.  So instead we return a NULL bucket, and make
 1971          * the code that allocates buckets smart enough to deal with it
 1972          *
 1973          * XXX: While we want this protection for the bucket zones so that
 1974          * recursion from the VM is handled (and the calling code that
 1975          * allocates buckets knows how to deal with it), we do not want
 1976          * to prevent allocation from the slab header zones (slabzone
 1977          * and slabrefzone) if uk_recurse is not zero for them.  The
 1978          * reason is that it could lead to NULL being returned for
 1979          * slab header allocations even in the M_WAITOK case, and the
 1980          * caller can't handle that. 
 1981          */
 1982         if (keg->uk_flags & UMA_ZFLAG_INTERNAL && keg->uk_recurse != 0)
 1983                 if (zone != slabzone && zone != slabrefzone && zone != zones)
 1984                         return (NULL);
 1985 
 1986         slab = NULL;
 1987 
 1988         for (;;) {
 1989                 /*
 1990                  * Find a slab with some space.  Prefer slabs that are partially
 1991                  * used over those that are totally full.  This helps to reduce
 1992                  * fragmentation.
 1993                  */
 1994                 if (keg->uk_free != 0) {
 1995                         if (!LIST_EMPTY(&keg->uk_part_slab)) {
 1996                                 slab = LIST_FIRST(&keg->uk_part_slab);
 1997                         } else {
 1998                                 slab = LIST_FIRST(&keg->uk_free_slab);
 1999                                 LIST_REMOVE(slab, us_link);
 2000                                 LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
 2001                                     us_link);
 2002                         }
 2003                         return (slab);
 2004                 }
 2005 
 2006                 /*
 2007                  * M_NOVM means don't ask at all!
 2008                  */
 2009                 if (flags & M_NOVM)
 2010                         break;
 2011 
 2012                 if (keg->uk_maxpages &&
 2013                     keg->uk_pages >= keg->uk_maxpages) {
 2014                         keg->uk_flags |= UMA_ZFLAG_FULL;
 2015 
 2016                         if (flags & M_NOWAIT)
 2017                                 break;
 2018                         else
 2019                                 msleep(keg, &keg->uk_lock, PVM,
 2020                                     "zonelimit", 0);
 2021                         continue;
 2022                 }
 2023                 keg->uk_recurse++;
 2024                 slab = slab_zalloc(zone, flags);
 2025                 keg->uk_recurse--;
 2026 
 2027                 /*
 2028                  * If we got a slab here it's safe to mark it partially used
 2029                  * and return.  We assume that the caller is going to remove
 2030                  * at least one item.
 2031                  */
 2032                 if (slab) {
 2033                         LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
 2034                         return (slab);
 2035                 }
 2036                 /*
 2037                  * We might not have been able to get a slab but another cpu
 2038                  * could have while we were unlocked.  Check again before we
 2039                  * fail.
 2040                  */
 2041                 if (flags & M_NOWAIT)
 2042                         flags |= M_NOVM;
 2043         }
 2044         return (slab);
 2045 }
 2046 
 2047 static void *
 2048 uma_slab_alloc(uma_zone_t zone, uma_slab_t slab)
 2049 {
 2050         uma_keg_t keg;
 2051         uma_slabrefcnt_t slabref;
 2052         void *item;
 2053         u_int8_t freei;
 2054 
 2055         keg = zone->uz_keg;
 2056 
 2057         freei = slab->us_firstfree;
 2058         if (keg->uk_flags & UMA_ZONE_REFCNT) {
 2059                 slabref = (uma_slabrefcnt_t)slab;
 2060                 slab->us_firstfree = slabref->us_freelist[freei].us_item;
 2061         } else {
 2062                 slab->us_firstfree = slab->us_freelist[freei].us_item;
 2063         }
 2064         item = slab->us_data + (keg->uk_rsize * freei);
 2065 
 2066         slab->us_freecount--;
 2067         keg->uk_free--;
 2068 #ifdef INVARIANTS
 2069         uma_dbg_alloc(zone, slab, item);
 2070 #endif
 2071         /* Move this slab to the full list */
 2072         if (slab->us_freecount == 0) {
 2073                 LIST_REMOVE(slab, us_link);
 2074                 LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
 2075         }
 2076 
 2077         return (item);
 2078 }
 2079 
 2080 static int
 2081 uma_zalloc_bucket(uma_zone_t zone, int flags)
 2082 {
 2083         uma_bucket_t bucket;
 2084         uma_slab_t slab;
 2085         int16_t saved;
 2086         int max, origflags = flags;
 2087 
 2088         /*
 2089          * Try this zone's free list first so we don't allocate extra buckets.
 2090          */
 2091         if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
 2092                 KASSERT(bucket->ub_cnt == 0,
 2093                     ("uma_zalloc_bucket: Bucket on free list is not empty."));
 2094                 LIST_REMOVE(bucket, ub_link);
 2095         } else {
 2096                 int bflags;
 2097 
 2098                 bflags = (flags & ~M_ZERO);
 2099                 if (zone->uz_keg->uk_flags & UMA_ZFLAG_CACHEONLY)
 2100                         bflags |= M_NOVM;
 2101 
 2102                 ZONE_UNLOCK(zone);
 2103                 bucket = bucket_alloc(zone->uz_count, bflags);
 2104                 ZONE_LOCK(zone);
 2105         }
 2106 
 2107         if (bucket == NULL)
 2108                 return (0);
 2109 
 2110 #ifdef SMP
 2111         /*
 2112          * This code is here to limit the number of simultaneous bucket fills
 2113          * for any given zone to the number of per cpu caches in this zone. This
 2114          * is done so that we don't allocate more memory than we really need.
 2115          */
 2116         if (zone->uz_fills >= mp_ncpus)
 2117                 goto done;
 2118 
 2119 #endif
 2120         zone->uz_fills++;
 2121 
 2122         max = MIN(bucket->ub_entries, zone->uz_count);
 2123         /* Try to keep the buckets totally full */
 2124         saved = bucket->ub_cnt;
 2125         while (bucket->ub_cnt < max &&
 2126             (slab = uma_zone_slab(zone, flags)) != NULL) {
 2127                 while (slab->us_freecount && bucket->ub_cnt < max) {
 2128                         bucket->ub_bucket[bucket->ub_cnt++] =
 2129                             uma_slab_alloc(zone, slab);
 2130                 }
 2131 
 2132                 /* Don't block on the next fill */
 2133                 flags |= M_NOWAIT;
 2134         }
 2135 
 2136         /*
 2137          * We unlock here because we need to call the zone's init.
 2138          * It should be safe to unlock because the slab dealt with
 2139          * above is already on the appropriate list within the keg
 2140          * and the bucket we filled is not yet on any list, so we
 2141          * own it.
 2142          */
 2143         if (zone->uz_init != NULL) {
 2144                 int i;
 2145 
 2146                 ZONE_UNLOCK(zone);
 2147                 for (i = saved; i < bucket->ub_cnt; i++)
 2148                         if (zone->uz_init(bucket->ub_bucket[i],
 2149                             zone->uz_keg->uk_size, origflags) != 0)
 2150                                 break;
 2151                 /*
 2152                  * If we couldn't initialize the whole bucket, put the
 2153                  * rest back onto the freelist.
 2154                  */
 2155                 if (i != bucket->ub_cnt) {
 2156                         int j;
 2157 
 2158                         for (j = i; j < bucket->ub_cnt; j++) {
 2159                                 uma_zfree_internal(zone, bucket->ub_bucket[j],
 2160                                     NULL, SKIP_FINI, 0);
 2161 #ifdef INVARIANTS
 2162                                 bucket->ub_bucket[j] = NULL;
 2163 #endif
 2164                         }
 2165                         bucket->ub_cnt = i;
 2166                 }
 2167                 ZONE_LOCK(zone);
 2168         }
 2169 
 2170         zone->uz_fills--;
 2171         if (bucket->ub_cnt != 0) {
 2172                 LIST_INSERT_HEAD(&zone->uz_full_bucket,
 2173                     bucket, ub_link);
 2174                 return (1);
 2175         }
 2176 #ifdef SMP
 2177 done:
 2178 #endif
 2179         bucket_free(bucket);
 2180 
 2181         return (0);
 2182 }
 2183 /*
 2184  * Allocates an item for an internal zone
 2185  *
 2186  * Arguments
 2187  *      zone   The zone to alloc for.
 2188  *      udata  The data to be passed to the constructor.
 2189  *      flags  M_WAITOK, M_NOWAIT, M_ZERO.
 2190  *
 2191  * Returns
 2192  *      NULL if there is no memory and M_NOWAIT is set
 2193  *      An item if successful
 2194  */
 2195 
 2196 static void *
 2197 uma_zalloc_internal(uma_zone_t zone, void *udata, int flags)
 2198 {
 2199         uma_keg_t keg;
 2200         uma_slab_t slab;
 2201         void *item;
 2202 
 2203         item = NULL;
 2204         keg = zone->uz_keg;
 2205 
 2206 #ifdef UMA_DEBUG_ALLOC
 2207         printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
 2208 #endif
 2209         ZONE_LOCK(zone);
 2210 
 2211         slab = uma_zone_slab(zone, flags);
 2212         if (slab == NULL) {
 2213                 zone->uz_fails++;
 2214                 ZONE_UNLOCK(zone);
 2215                 return (NULL);
 2216         }
 2217 
 2218         item = uma_slab_alloc(zone, slab);
 2219 
 2220         zone->uz_allocs++;
 2221 
 2222         ZONE_UNLOCK(zone);
 2223 
 2224         /*
 2225          * We have to call both the zone's init (not the keg's init)
 2226          * and the zone's ctor.  This is because the item is going from
 2227          * a keg slab directly to the user, and the user is expecting it
 2228          * to be both zone-init'd as well as zone-ctor'd.
 2229          */
 2230         if (zone->uz_init != NULL) {
 2231                 if (zone->uz_init(item, keg->uk_size, flags) != 0) {
 2232                         uma_zfree_internal(zone, item, udata, SKIP_FINI,
 2233                             ZFREE_STATFAIL | ZFREE_STATFREE);
 2234                         return (NULL);
 2235                 }
 2236         }
 2237         if (zone->uz_ctor != NULL) {
 2238                 if (zone->uz_ctor(item, keg->uk_size, udata, flags) != 0) {
 2239                         uma_zfree_internal(zone, item, udata, SKIP_DTOR,
 2240                             ZFREE_STATFAIL | ZFREE_STATFREE);
 2241                         return (NULL);
 2242                 }
 2243         }
 2244         if (flags & M_ZERO)
 2245                 bzero(item, keg->uk_size);
 2246 
 2247         return (item);
 2248 }
 2249 
 2250 /* See uma.h */
 2251 void
 2252 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
 2253 {
 2254         uma_keg_t keg;
 2255         uma_cache_t cache;
 2256         uma_bucket_t bucket;
 2257         int bflags;
 2258         int cpu;
 2259 
 2260         keg = zone->uz_keg;
 2261 
 2262 #ifdef UMA_DEBUG_ALLOC_1
 2263         printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
 2264 #endif
 2265         CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
 2266             zone->uz_name);
 2267 
 2268         if (zone->uz_dtor)
 2269                 zone->uz_dtor(item, keg->uk_size, udata);
 2270 #ifdef INVARIANTS
 2271         ZONE_LOCK(zone);
 2272         if (keg->uk_flags & UMA_ZONE_MALLOC)
 2273                 uma_dbg_free(zone, udata, item);
 2274         else
 2275                 uma_dbg_free(zone, NULL, item);
 2276         ZONE_UNLOCK(zone);
 2277 #endif
 2278         /*
 2279          * The race here is acceptable.  If we miss it we'll just have to wait
 2280          * a little longer for the limits to be reset.
 2281          */
 2282         if (keg->uk_flags & UMA_ZFLAG_FULL)
 2283                 goto zfree_internal;
 2284 
 2285         /*
 2286          * If possible, free to the per-CPU cache.  There are two
 2287          * requirements for safe access to the per-CPU cache: (1) the thread
 2288          * accessing the cache must not be preempted or yield during access,
 2289          * and (2) the thread must not migrate CPUs without switching which
 2290          * cache it accesses.  We rely on a critical section to prevent
 2291          * preemption and migration.  We release the critical section in
 2292          * order to acquire the zone mutex if we are unable to free to the
 2293          * current cache; when we re-acquire the critical section, we must
 2294          * detect and handle migration if it has occurred.
 2295          */
 2296 zfree_restart:
 2297         critical_enter();
 2298         cpu = curcpu;
 2299         cache = &zone->uz_cpu[cpu];
 2300 
 2301 zfree_start:
 2302         bucket = cache->uc_freebucket;
 2303 
 2304         if (bucket) {
 2305                 /*
 2306                  * Do we have room in our bucket? It is OK for this uz count
 2307                  * check to be slightly out of sync.
 2308                  */
 2309 
 2310                 if (bucket->ub_cnt < bucket->ub_entries) {
 2311                         KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
 2312                             ("uma_zfree: Freeing to non free bucket index."));
 2313                         bucket->ub_bucket[bucket->ub_cnt] = item;
 2314                         bucket->ub_cnt++;
 2315                         cache->uc_frees++;
 2316                         critical_exit();
 2317                         return;
 2318                 } else if (cache->uc_allocbucket) {
 2319 #ifdef UMA_DEBUG_ALLOC
 2320                         printf("uma_zfree: Swapping buckets.\n");
 2321 #endif
 2322                         /*
 2323                          * We have run out of space in our freebucket.
 2324                          * See if we can switch with our alloc bucket.
 2325                          */
 2326                         if (cache->uc_allocbucket->ub_cnt <
 2327                             cache->uc_freebucket->ub_cnt) {
 2328                                 bucket = cache->uc_freebucket;
 2329                                 cache->uc_freebucket = cache->uc_allocbucket;
 2330                                 cache->uc_allocbucket = bucket;
 2331                                 goto zfree_start;
 2332                         }
 2333                 }
 2334         }
 2335         /*
 2336          * We can get here for two reasons:
 2337          *
 2338          * 1) The buckets are NULL
 2339          * 2) The alloc and free buckets are both somewhat full.
 2340          *
 2341          * We must go back the zone, which requires acquiring the zone lock,
 2342          * which in turn means we must release and re-acquire the critical
 2343          * section.  Since the critical section is released, we may be
 2344          * preempted or migrate.  As such, make sure not to maintain any
 2345          * thread-local state specific to the cache from prior to releasing
 2346          * the critical section.
 2347          */
 2348         critical_exit();
 2349         ZONE_LOCK(zone);
 2350         critical_enter();
 2351         cpu = curcpu;
 2352         cache = &zone->uz_cpu[cpu];
 2353         if (cache->uc_freebucket != NULL) {
 2354                 if (cache->uc_freebucket->ub_cnt <
 2355                     cache->uc_freebucket->ub_entries) {
 2356                         ZONE_UNLOCK(zone);
 2357                         goto zfree_start;
 2358                 }
 2359                 if (cache->uc_allocbucket != NULL &&
 2360                     (cache->uc_allocbucket->ub_cnt <
 2361                     cache->uc_freebucket->ub_cnt)) {
 2362                         ZONE_UNLOCK(zone);
 2363                         goto zfree_start;
 2364                 }
 2365         }
 2366 
 2367         /* Since we have locked the zone we may as well send back our stats */
 2368         zone->uz_allocs += cache->uc_allocs;
 2369         cache->uc_allocs = 0;
 2370         zone->uz_frees += cache->uc_frees;
 2371         cache->uc_frees = 0;
 2372 
 2373         bucket = cache->uc_freebucket;
 2374         cache->uc_freebucket = NULL;
 2375 
 2376         /* Can we throw this on the zone full list? */
 2377         if (bucket != NULL) {
 2378 #ifdef UMA_DEBUG_ALLOC
 2379                 printf("uma_zfree: Putting old bucket on the free list.\n");
 2380 #endif
 2381                 /* ub_cnt is pointing to the last free item */
 2382                 KASSERT(bucket->ub_cnt != 0,
 2383                     ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
 2384                 LIST_INSERT_HEAD(&zone->uz_full_bucket,
 2385                     bucket, ub_link);
 2386         }
 2387         if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
 2388                 LIST_REMOVE(bucket, ub_link);
 2389                 ZONE_UNLOCK(zone);
 2390                 cache->uc_freebucket = bucket;
 2391                 goto zfree_start;
 2392         }
 2393         /* We are no longer associated with this CPU. */
 2394         critical_exit();
 2395 
 2396         /* And the zone.. */
 2397         ZONE_UNLOCK(zone);
 2398 
 2399 #ifdef UMA_DEBUG_ALLOC
 2400         printf("uma_zfree: Allocating new free bucket.\n");
 2401 #endif
 2402         bflags = M_NOWAIT;
 2403 
 2404         if (keg->uk_flags & UMA_ZFLAG_CACHEONLY)
 2405                 bflags |= M_NOVM;
 2406         bucket = bucket_alloc(zone->uz_count, bflags);
 2407         if (bucket) {
 2408                 ZONE_LOCK(zone);
 2409                 LIST_INSERT_HEAD(&zone->uz_free_bucket,
 2410                     bucket, ub_link);
 2411                 ZONE_UNLOCK(zone);
 2412                 goto zfree_restart;
 2413         }
 2414 
 2415         /*
 2416          * If nothing else caught this, we'll just do an internal free.
 2417          */
 2418 zfree_internal:
 2419         uma_zfree_internal(zone, item, udata, SKIP_DTOR, ZFREE_STATFREE);
 2420 
 2421         return;
 2422 }
 2423 
 2424 /*
 2425  * Frees an item to an INTERNAL zone or allocates a free bucket
 2426  *
 2427  * Arguments:
 2428  *      zone   The zone to free to
 2429  *      item   The item we're freeing
 2430  *      udata  User supplied data for the dtor
 2431  *      skip   Skip dtors and finis
 2432  */
 2433 static void
 2434 uma_zfree_internal(uma_zone_t zone, void *item, void *udata,
 2435     enum zfreeskip skip, int flags)
 2436 {
 2437         uma_slab_t slab;
 2438         uma_slabrefcnt_t slabref;
 2439         uma_keg_t keg;
 2440         u_int8_t *mem;
 2441         u_int8_t freei;
 2442 
 2443         keg = zone->uz_keg;
 2444 
 2445         if (skip < SKIP_DTOR && zone->uz_dtor)
 2446                 zone->uz_dtor(item, keg->uk_size, udata);
 2447         if (skip < SKIP_FINI && zone->uz_fini)
 2448                 zone->uz_fini(item, keg->uk_size);
 2449 
 2450         ZONE_LOCK(zone);
 2451 
 2452         if (flags & ZFREE_STATFAIL)
 2453                 zone->uz_fails++;
 2454         if (flags & ZFREE_STATFREE)
 2455                 zone->uz_frees++;
 2456 
 2457         if (!(keg->uk_flags & UMA_ZONE_MALLOC)) {
 2458                 mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
 2459                 if (keg->uk_flags & UMA_ZONE_HASH)
 2460                         slab = hash_sfind(&keg->uk_hash, mem);
 2461                 else {
 2462                         mem += keg->uk_pgoff;
 2463                         slab = (uma_slab_t)mem;
 2464                 }
 2465         } else {
 2466                 slab = (uma_slab_t)udata;
 2467         }
 2468 
 2469         /* Do we need to remove from any lists? */
 2470         if (slab->us_freecount+1 == keg->uk_ipers) {
 2471                 LIST_REMOVE(slab, us_link);
 2472                 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
 2473         } else if (slab->us_freecount == 0) {
 2474                 LIST_REMOVE(slab, us_link);
 2475                 LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
 2476         }
 2477 
 2478         /* Slab management stuff */
 2479         freei = ((unsigned long)item - (unsigned long)slab->us_data)
 2480                 / keg->uk_rsize;
 2481 
 2482 #ifdef INVARIANTS
 2483         if (!skip)
 2484                 uma_dbg_free(zone, slab, item);
 2485 #endif
 2486 
 2487         if (keg->uk_flags & UMA_ZONE_REFCNT) {
 2488                 slabref = (uma_slabrefcnt_t)slab;
 2489                 slabref->us_freelist[freei].us_item = slab->us_firstfree;
 2490         } else {
 2491                 slab->us_freelist[freei].us_item = slab->us_firstfree;
 2492         }
 2493         slab->us_firstfree = freei;
 2494         slab->us_freecount++;
 2495 
 2496         /* Zone statistics */
 2497         keg->uk_free++;
 2498 
 2499         if (keg->uk_flags & UMA_ZFLAG_FULL) {
 2500                 if (keg->uk_pages < keg->uk_maxpages)
 2501                         keg->uk_flags &= ~UMA_ZFLAG_FULL;
 2502 
 2503                 /* 
 2504                  * We can handle one more allocation. Since we're clearing ZFLAG_FULL,
 2505                  * wake up all procs blocked on pages. This should be uncommon, so 
 2506                  * keeping this simple for now (rather than adding count of blocked 
 2507                  * threads etc).
 2508                  */
 2509                 wakeup(keg);
 2510         }
 2511 
 2512         ZONE_UNLOCK(zone);
 2513 }
 2514 
 2515 /* See uma.h */
 2516 void
 2517 uma_zone_set_max(uma_zone_t zone, int nitems)
 2518 {
 2519         uma_keg_t keg;
 2520 
 2521         keg = zone->uz_keg;
 2522         ZONE_LOCK(zone);
 2523         if (keg->uk_ppera > 1)
 2524                 keg->uk_maxpages = nitems * keg->uk_ppera;
 2525         else
 2526                 keg->uk_maxpages = nitems / keg->uk_ipers;
 2527 
 2528         if (keg->uk_maxpages * keg->uk_ipers < nitems)
 2529                 keg->uk_maxpages++;
 2530 
 2531         ZONE_UNLOCK(zone);
 2532 }
 2533 
 2534 /* See uma.h */
 2535 void
 2536 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
 2537 {
 2538         ZONE_LOCK(zone);
 2539         KASSERT(zone->uz_keg->uk_pages == 0,
 2540             ("uma_zone_set_init on non-empty keg"));
 2541         zone->uz_keg->uk_init = uminit;
 2542         ZONE_UNLOCK(zone);
 2543 }
 2544 
 2545 /* See uma.h */
 2546 void
 2547 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
 2548 {
 2549         ZONE_LOCK(zone);
 2550         KASSERT(zone->uz_keg->uk_pages == 0,
 2551             ("uma_zone_set_fini on non-empty keg"));
 2552         zone->uz_keg->uk_fini = fini;
 2553         ZONE_UNLOCK(zone);
 2554 }
 2555 
 2556 /* See uma.h */
 2557 void
 2558 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
 2559 {
 2560         ZONE_LOCK(zone);
 2561         KASSERT(zone->uz_keg->uk_pages == 0,
 2562             ("uma_zone_set_zinit on non-empty keg"));
 2563         zone->uz_init = zinit;
 2564         ZONE_UNLOCK(zone);
 2565 }
 2566 
 2567 /* See uma.h */
 2568 void
 2569 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
 2570 {
 2571         ZONE_LOCK(zone);
 2572         KASSERT(zone->uz_keg->uk_pages == 0,
 2573             ("uma_zone_set_zfini on non-empty keg"));
 2574         zone->uz_fini = zfini;
 2575         ZONE_UNLOCK(zone);
 2576 }
 2577 
 2578 /* See uma.h */
 2579 /* XXX uk_freef is not actually used with the zone locked */
 2580 void
 2581 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
 2582 {
 2583         ZONE_LOCK(zone);
 2584         zone->uz_keg->uk_freef = freef;
 2585         ZONE_UNLOCK(zone);
 2586 }
 2587 
 2588 /* See uma.h */
 2589 /* XXX uk_allocf is not actually used with the zone locked */
 2590 void
 2591 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
 2592 {
 2593         ZONE_LOCK(zone);
 2594         zone->uz_keg->uk_flags |= UMA_ZFLAG_PRIVALLOC;
 2595         zone->uz_keg->uk_allocf = allocf;
 2596         ZONE_UNLOCK(zone);
 2597 }
 2598 
 2599 /* See uma.h */
 2600 int
 2601 uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int count)
 2602 {
 2603         uma_keg_t keg;
 2604         vm_offset_t kva;
 2605         int pages;
 2606 
 2607         keg = zone->uz_keg;
 2608         pages = count / keg->uk_ipers;
 2609 
 2610         if (pages * keg->uk_ipers < count)
 2611                 pages++;
 2612 
 2613         kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
 2614 
 2615         if (kva == 0)
 2616                 return (0);
 2617         if (obj == NULL) {
 2618                 obj = vm_object_allocate(OBJT_DEFAULT,
 2619                     pages);
 2620         } else {
 2621                 VM_OBJECT_LOCK_INIT(obj, "uma object");
 2622                 _vm_object_allocate(OBJT_DEFAULT,
 2623                     pages, obj);
 2624         }
 2625         ZONE_LOCK(zone);
 2626         keg->uk_kva = kva;
 2627         keg->uk_obj = obj;
 2628         keg->uk_maxpages = pages;
 2629         keg->uk_allocf = obj_alloc;
 2630         keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC;
 2631         ZONE_UNLOCK(zone);
 2632         return (1);
 2633 }
 2634 
 2635 /* See uma.h */
 2636 void
 2637 uma_prealloc(uma_zone_t zone, int items)
 2638 {
 2639         int slabs;
 2640         uma_slab_t slab;
 2641         uma_keg_t keg;
 2642 
 2643         keg = zone->uz_keg;
 2644         ZONE_LOCK(zone);
 2645         slabs = items / keg->uk_ipers;
 2646         if (slabs * keg->uk_ipers < items)
 2647                 slabs++;
 2648         while (slabs > 0) {
 2649                 slab = slab_zalloc(zone, M_WAITOK);
 2650                 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
 2651                 slabs--;
 2652         }
 2653         ZONE_UNLOCK(zone);
 2654 }
 2655 
 2656 /* See uma.h */
 2657 u_int32_t *
 2658 uma_find_refcnt(uma_zone_t zone, void *item)
 2659 {
 2660         uma_slabrefcnt_t slabref;
 2661         uma_keg_t keg;
 2662         u_int32_t *refcnt;
 2663         int idx;
 2664 
 2665         keg = zone->uz_keg;
 2666         slabref = (uma_slabrefcnt_t)vtoslab((vm_offset_t)item &
 2667             (~UMA_SLAB_MASK));
 2668         KASSERT(slabref != NULL && slabref->us_keg->uk_flags & UMA_ZONE_REFCNT,
 2669             ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
 2670         idx = ((unsigned long)item - (unsigned long)slabref->us_data)
 2671             / keg->uk_rsize;
 2672         refcnt = &slabref->us_freelist[idx].us_refcnt;
 2673         return refcnt;
 2674 }
 2675 
 2676 /* See uma.h */
 2677 void
 2678 uma_reclaim(void)
 2679 {
 2680 #ifdef UMA_DEBUG
 2681         printf("UMA: vm asked us to release pages!\n");
 2682 #endif
 2683         bucket_enable();
 2684         zone_foreach(zone_drain);
 2685         /*
 2686          * Some slabs may have been freed but this zone will be visited early
 2687          * we visit again so that we can free pages that are empty once other
 2688          * zones are drained.  We have to do the same for buckets.
 2689          */
 2690         zone_drain(slabzone);
 2691         zone_drain(slabrefzone);
 2692         bucket_zone_drain();
 2693 }
 2694 
 2695 /* See uma.h */
 2696 int
 2697 uma_zone_exhausted(uma_zone_t zone)
 2698 {
 2699         int full;
 2700 
 2701         ZONE_LOCK(zone);
 2702         full = (zone->uz_keg->uk_flags & UMA_ZFLAG_FULL);
 2703         ZONE_UNLOCK(zone);
 2704         return (full);  
 2705 }
 2706 
 2707 int
 2708 uma_zone_exhausted_nolock(uma_zone_t zone)
 2709 {
 2710         return (zone->uz_keg->uk_flags & UMA_ZFLAG_FULL);
 2711 }
 2712 
 2713 void *
 2714 uma_large_malloc(int size, int wait)
 2715 {
 2716         void *mem;
 2717         uma_slab_t slab;
 2718         u_int8_t flags;
 2719 
 2720         slab = uma_zalloc_internal(slabzone, NULL, wait);
 2721         if (slab == NULL)
 2722                 return (NULL);
 2723         mem = page_alloc(NULL, size, &flags, wait);
 2724         if (mem) {
 2725                 vsetslab((vm_offset_t)mem, slab);
 2726                 slab->us_data = mem;
 2727                 slab->us_flags = flags | UMA_SLAB_MALLOC;
 2728                 slab->us_size = size;
 2729         } else {
 2730                 uma_zfree_internal(slabzone, slab, NULL, SKIP_NONE,
 2731                     ZFREE_STATFAIL | ZFREE_STATFREE);
 2732         }
 2733 
 2734         return (mem);
 2735 }
 2736 
 2737 void
 2738 uma_large_free(uma_slab_t slab)
 2739 {
 2740         vsetobj((vm_offset_t)slab->us_data, kmem_object);
 2741         page_free(slab->us_data, slab->us_size, slab->us_flags);
 2742         uma_zfree_internal(slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE);
 2743 }
 2744 
 2745 void
 2746 uma_print_stats(void)
 2747 {
 2748         zone_foreach(uma_print_zone);
 2749 }
 2750 
 2751 static void
 2752 slab_print(uma_slab_t slab)
 2753 {
 2754         printf("slab: keg %p, data %p, freecount %d, firstfree %d\n",
 2755                 slab->us_keg, slab->us_data, slab->us_freecount,
 2756                 slab->us_firstfree);
 2757 }
 2758 
 2759 static void
 2760 cache_print(uma_cache_t cache)
 2761 {
 2762         printf("alloc: %p(%d), free: %p(%d)\n",
 2763                 cache->uc_allocbucket,
 2764                 cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
 2765                 cache->uc_freebucket,
 2766                 cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
 2767 }
 2768 
 2769 void
 2770 uma_print_zone(uma_zone_t zone)
 2771 {
 2772         uma_cache_t cache;
 2773         uma_keg_t keg;
 2774         uma_slab_t slab;
 2775         int i;
 2776 
 2777         keg = zone->uz_keg;
 2778         printf("%s(%p) size %d(%d) flags %d ipers %d ppera %d out %d free %d\n",
 2779             zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
 2780             keg->uk_ipers, keg->uk_ppera,
 2781             (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
 2782         printf("Part slabs:\n");
 2783         LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
 2784                 slab_print(slab);
 2785         printf("Free slabs:\n");
 2786         LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
 2787                 slab_print(slab);
 2788         printf("Full slabs:\n");
 2789         LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
 2790                 slab_print(slab);
 2791         for (i = 0; i <= mp_maxid; i++) {
 2792                 if (CPU_ABSENT(i))
 2793                         continue;
 2794                 cache = &zone->uz_cpu[i];
 2795                 printf("CPU %d Cache:\n", i);
 2796                 cache_print(cache);
 2797         }
 2798 }
 2799 
 2800 /*
 2801  * Generate statistics across both the zone and its per-cpu cache's.  Return
 2802  * desired statistics if the pointer is non-NULL for that statistic.
 2803  *
 2804  * Note: does not update the zone statistics, as it can't safely clear the
 2805  * per-CPU cache statistic.
 2806  *
 2807  * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
 2808  * safe from off-CPU; we should modify the caches to track this information
 2809  * directly so that we don't have to.
 2810  */
 2811 static void
 2812 uma_zone_sumstat(uma_zone_t z, int *cachefreep, u_int64_t *allocsp,
 2813     u_int64_t *freesp)
 2814 {
 2815         uma_cache_t cache;
 2816         u_int64_t allocs, frees;
 2817         int cachefree, cpu;
 2818 
 2819         allocs = frees = 0;
 2820         cachefree = 0;
 2821         for (cpu = 0; cpu <= mp_maxid; cpu++) {
 2822                 if (CPU_ABSENT(cpu))
 2823                         continue;
 2824                 cache = &z->uz_cpu[cpu];
 2825                 if (cache->uc_allocbucket != NULL)
 2826                         cachefree += cache->uc_allocbucket->ub_cnt;
 2827                 if (cache->uc_freebucket != NULL)
 2828                         cachefree += cache->uc_freebucket->ub_cnt;
 2829                 allocs += cache->uc_allocs;
 2830                 frees += cache->uc_frees;
 2831         }
 2832         allocs += z->uz_allocs;
 2833         frees += z->uz_frees;
 2834         if (cachefreep != NULL)
 2835                 *cachefreep = cachefree;
 2836         if (allocsp != NULL)
 2837                 *allocsp = allocs;
 2838         if (freesp != NULL)
 2839                 *freesp = frees;
 2840 }
 2841 
 2842 /*
 2843  * Sysctl handler for vm.zone
 2844  *
 2845  * stolen from vm_zone.c
 2846  */
 2847 static int
 2848 sysctl_vm_zone(SYSCTL_HANDLER_ARGS)
 2849 {
 2850         int error, len, cnt;
 2851         const int linesize = 128;       /* conservative */
 2852         int totalfree;
 2853         char *tmpbuf, *offset;
 2854         uma_zone_t z;
 2855         uma_keg_t zk;
 2856         char *p;
 2857         int cachefree;
 2858         uma_bucket_t bucket;
 2859         u_int64_t allocs, frees;
 2860 
 2861         cnt = 0;
 2862         mtx_lock(&uma_mtx);
 2863         LIST_FOREACH(zk, &uma_kegs, uk_link) {
 2864                 LIST_FOREACH(z, &zk->uk_zones, uz_link)
 2865                         cnt++;
 2866         }
 2867         mtx_unlock(&uma_mtx);
 2868         MALLOC(tmpbuf, char *, (cnt == 0 ? 1 : cnt) * linesize,
 2869                         M_TEMP, M_WAITOK);
 2870         len = snprintf(tmpbuf, linesize,
 2871             "\nITEM            SIZE     LIMIT     USED    FREE  REQUESTS\n\n");
 2872         if (cnt == 0)
 2873                 tmpbuf[len - 1] = '\0';
 2874         error = SYSCTL_OUT(req, tmpbuf, cnt == 0 ? len-1 : len);
 2875         if (error || cnt == 0)
 2876                 goto out;
 2877         offset = tmpbuf;
 2878         mtx_lock(&uma_mtx);
 2879         LIST_FOREACH(zk, &uma_kegs, uk_link) {
 2880           LIST_FOREACH(z, &zk->uk_zones, uz_link) {
 2881                 if (cnt == 0)   /* list may have changed size */
 2882                         break;
 2883                 ZONE_LOCK(z);
 2884                 cachefree = 0;
 2885                 if (!(zk->uk_flags & UMA_ZFLAG_INTERNAL)) {
 2886                         uma_zone_sumstat(z, &cachefree, &allocs, &frees);
 2887                 } else {
 2888                         allocs = z->uz_allocs;
 2889                         frees = z->uz_frees;
 2890                 }
 2891 
 2892                 LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link) {
 2893                         cachefree += bucket->ub_cnt;
 2894                 }
 2895                 totalfree = zk->uk_free + cachefree;
 2896                 len = snprintf(offset, linesize,
 2897                     "%-12.12s  %6.6u, %8.8u, %6.6u, %6.6u, %8.8llu\n",
 2898                     z->uz_name, zk->uk_size,
 2899                     zk->uk_maxpages * zk->uk_ipers,
 2900                     (zk->uk_ipers * (zk->uk_pages / zk->uk_ppera)) - totalfree,
 2901                     totalfree,
 2902                     (unsigned long long)allocs);
 2903                 ZONE_UNLOCK(z);
 2904                 for (p = offset + 12; p > offset && *p == ' '; --p)
 2905                         /* nothing */ ;
 2906                 p[1] = ':';
 2907                 cnt--;
 2908                 offset += len;
 2909           }
 2910         }
 2911         mtx_unlock(&uma_mtx);
 2912         *offset++ = '\0';
 2913         error = SYSCTL_OUT(req, tmpbuf, offset - tmpbuf);
 2914 out:
 2915         FREE(tmpbuf, M_TEMP);
 2916         return (error);
 2917 }
 2918 
 2919 static int
 2920 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
 2921 {
 2922         uma_keg_t kz;
 2923         uma_zone_t z;
 2924         int count;
 2925 
 2926         count = 0;
 2927         mtx_lock(&uma_mtx);
 2928         LIST_FOREACH(kz, &uma_kegs, uk_link) {
 2929                 LIST_FOREACH(z, &kz->uk_zones, uz_link)
 2930                         count++;
 2931         }
 2932         mtx_unlock(&uma_mtx);
 2933         return (sysctl_handle_int(oidp, &count, 0, req));
 2934 }
 2935 
 2936 static int
 2937 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
 2938 {
 2939         struct uma_stream_header ush;
 2940         struct uma_type_header uth;
 2941         struct uma_percpu_stat ups;
 2942         uma_bucket_t bucket;
 2943         struct sbuf sbuf;
 2944         uma_cache_t cache;
 2945         uma_keg_t kz;
 2946         uma_zone_t z;
 2947         char *buffer;
 2948         int buflen, count, error, i;
 2949 
 2950         mtx_lock(&uma_mtx);
 2951 restart:
 2952         mtx_assert(&uma_mtx, MA_OWNED);
 2953         count = 0;
 2954         LIST_FOREACH(kz, &uma_kegs, uk_link) {
 2955                 LIST_FOREACH(z, &kz->uk_zones, uz_link)
 2956                         count++;
 2957         }
 2958         mtx_unlock(&uma_mtx);
 2959 
 2960         buflen = sizeof(ush) + count * (sizeof(uth) + sizeof(ups) *
 2961             (mp_maxid + 1)) + 1;
 2962         buffer = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
 2963 
 2964         mtx_lock(&uma_mtx);
 2965         i = 0;
 2966         LIST_FOREACH(kz, &uma_kegs, uk_link) {
 2967                 LIST_FOREACH(z, &kz->uk_zones, uz_link)
 2968                         i++;
 2969         }
 2970         if (i > count) {
 2971                 free(buffer, M_TEMP);
 2972                 goto restart;
 2973         }
 2974         count =  i;
 2975 
 2976         sbuf_new(&sbuf, buffer, buflen, SBUF_FIXEDLEN);
 2977 
 2978         /*
 2979          * Insert stream header.
 2980          */
 2981         bzero(&ush, sizeof(ush));
 2982         ush.ush_version = UMA_STREAM_VERSION;
 2983         ush.ush_maxcpus = (mp_maxid + 1);
 2984         ush.ush_count = count;
 2985         if (sbuf_bcat(&sbuf, &ush, sizeof(ush)) < 0) {
 2986                 mtx_unlock(&uma_mtx);
 2987                 error = ENOMEM;
 2988                 goto out;
 2989         }
 2990 
 2991         LIST_FOREACH(kz, &uma_kegs, uk_link) {
 2992                 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
 2993                         bzero(&uth, sizeof(uth));
 2994                         ZONE_LOCK(z);
 2995                         strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
 2996                         uth.uth_align = kz->uk_align;
 2997                         uth.uth_pages = kz->uk_pages;
 2998                         uth.uth_keg_free = kz->uk_free;
 2999                         uth.uth_size = kz->uk_size;
 3000                         uth.uth_rsize = kz->uk_rsize;
 3001                         uth.uth_maxpages = kz->uk_maxpages;
 3002                         if (kz->uk_ppera > 1)
 3003                                 uth.uth_limit = kz->uk_maxpages /
 3004                                     kz->uk_ppera;
 3005                         else
 3006                                 uth.uth_limit = kz->uk_maxpages *
 3007                                     kz->uk_ipers;
 3008 
 3009                         /*
 3010                          * A zone is secondary is it is not the first entry
 3011                          * on the keg's zone list.
 3012                          */
 3013                         if ((kz->uk_flags & UMA_ZONE_SECONDARY) &&
 3014                             (LIST_FIRST(&kz->uk_zones) != z))
 3015                                 uth.uth_zone_flags = UTH_ZONE_SECONDARY;
 3016 
 3017                         LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
 3018                                 uth.uth_zone_free += bucket->ub_cnt;
 3019                         uth.uth_allocs = z->uz_allocs;
 3020                         uth.uth_frees = z->uz_frees;
 3021                         uth.uth_fails = z->uz_fails;
 3022                         if (sbuf_bcat(&sbuf, &uth, sizeof(uth)) < 0) {
 3023                                 ZONE_UNLOCK(z);
 3024                                 mtx_unlock(&uma_mtx);
 3025                                 error = ENOMEM;
 3026                                 goto out;
 3027                         }
 3028                         /*
 3029                          * While it is not normally safe to access the cache
 3030                          * bucket pointers while not on the CPU that owns the
 3031                          * cache, we only allow the pointers to be exchanged
 3032                          * without the zone lock held, not invalidated, so
 3033                          * accept the possible race associated with bucket
 3034                          * exchange during monitoring.
 3035                          */
 3036                         for (i = 0; i < (mp_maxid + 1); i++) {
 3037                                 bzero(&ups, sizeof(ups));
 3038                                 if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
 3039                                         goto skip;
 3040                                 if (CPU_ABSENT(i))
 3041                                         goto skip;
 3042                                 cache = &z->uz_cpu[i];
 3043                                 if (cache->uc_allocbucket != NULL)
 3044                                         ups.ups_cache_free +=
 3045                                             cache->uc_allocbucket->ub_cnt;
 3046                                 if (cache->uc_freebucket != NULL)
 3047                                         ups.ups_cache_free +=
 3048                                             cache->uc_freebucket->ub_cnt;
 3049                                 ups.ups_allocs = cache->uc_allocs;
 3050                                 ups.ups_frees = cache->uc_frees;
 3051 skip:
 3052                                 if (sbuf_bcat(&sbuf, &ups, sizeof(ups)) < 0) {
 3053                                         ZONE_UNLOCK(z);
 3054                                         mtx_unlock(&uma_mtx);
 3055                                         error = ENOMEM;
 3056                                         goto out;
 3057                                 }
 3058                         }
 3059                         ZONE_UNLOCK(z);
 3060                 }
 3061         }
 3062         mtx_unlock(&uma_mtx);
 3063         sbuf_finish(&sbuf);
 3064         error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
 3065 out:
 3066         free(buffer, M_TEMP);
 3067         return (error);
 3068 }
 3069 
 3070 #ifdef DDB
 3071 DB_SHOW_COMMAND(uma, db_show_uma)
 3072 {
 3073         u_int64_t allocs, frees;
 3074         uma_bucket_t bucket;
 3075         uma_keg_t kz;
 3076         uma_zone_t z;
 3077         int cachefree;
 3078 
 3079         db_printf("%18s %12s %12s %12s %8s\n", "Zone", "Allocs", "Frees",
 3080             "Used", "Cache");
 3081         LIST_FOREACH(kz, &uma_kegs, uk_link) {
 3082                 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
 3083                         if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
 3084                                 allocs = z->uz_allocs;
 3085                                 frees = z->uz_frees;
 3086                                 cachefree = 0;
 3087                         } else
 3088                                 uma_zone_sumstat(z, &cachefree, &allocs,
 3089                                     &frees);
 3090                         if (!((kz->uk_flags & UMA_ZONE_SECONDARY) &&
 3091                             (LIST_FIRST(&kz->uk_zones) != z)))
 3092                                 cachefree += kz->uk_free;
 3093                         LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
 3094                                 cachefree += bucket->ub_cnt;
 3095                         db_printf("%18s %12ju %12ju %12ju %8d\n", z->uz_name,
 3096                             allocs, frees, allocs - frees, cachefree);
 3097                 }
 3098         }
 3099 }
 3100 #endif

Cache object: ffce7a9f3ff97bdedc5d234c0f5dbab3


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.