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


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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_malloc.c

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    1 /*-
    2  * Copyright (c) 1987, 1991, 1993
    3  *      The Regents of the University of California.
    4  * Copyright (c) 2005-2009 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, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 4. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)kern_malloc.c       8.3 (Berkeley) 1/4/94
   32  */
   33 
   34 /*
   35  * Kernel malloc(9) implementation -- general purpose kernel memory allocator
   36  * based on memory types.  Back end is implemented using the UMA(9) zone
   37  * allocator.  A set of fixed-size buckets are used for smaller allocations,
   38  * and a special UMA allocation interface is used for larger allocations.
   39  * Callers declare memory types, and statistics are maintained independently
   40  * for each memory type.  Statistics are maintained per-CPU for performance
   41  * reasons.  See malloc(9) and comments in malloc.h for a detailed
   42  * description.
   43  */
   44 
   45 #include <sys/cdefs.h>
   46 __FBSDID("$FreeBSD: releng/8.2/sys/kern/kern_malloc.c 213921 2010-10-16 11:24:27Z avg $");
   47 
   48 #include "opt_ddb.h"
   49 #include "opt_kdtrace.h"
   50 #include "opt_vm.h"
   51 
   52 #include <sys/param.h>
   53 #include <sys/systm.h>
   54 #include <sys/kdb.h>
   55 #include <sys/kernel.h>
   56 #include <sys/lock.h>
   57 #include <sys/malloc.h>
   58 #include <sys/mbuf.h>
   59 #include <sys/mutex.h>
   60 #include <sys/vmmeter.h>
   61 #include <sys/proc.h>
   62 #include <sys/sbuf.h>
   63 #include <sys/sysctl.h>
   64 #include <sys/time.h>
   65 
   66 #include <vm/vm.h>
   67 #include <vm/pmap.h>
   68 #include <vm/vm_param.h>
   69 #include <vm/vm_kern.h>
   70 #include <vm/vm_extern.h>
   71 #include <vm/vm_map.h>
   72 #include <vm/vm_page.h>
   73 #include <vm/uma.h>
   74 #include <vm/uma_int.h>
   75 #include <vm/uma_dbg.h>
   76 
   77 #ifdef DEBUG_MEMGUARD
   78 #include <vm/memguard.h>
   79 #endif
   80 #ifdef DEBUG_REDZONE
   81 #include <vm/redzone.h>
   82 #endif
   83 
   84 #if defined(INVARIANTS) && defined(__i386__)
   85 #include <machine/cpu.h>
   86 #endif
   87 
   88 #include <ddb/ddb.h>
   89 
   90 #ifdef KDTRACE_HOOKS
   91 #include <sys/dtrace_bsd.h>
   92 
   93 dtrace_malloc_probe_func_t      dtrace_malloc_probe;
   94 #endif
   95 
   96 /*
   97  * When realloc() is called, if the new size is sufficiently smaller than
   98  * the old size, realloc() will allocate a new, smaller block to avoid
   99  * wasting memory. 'Sufficiently smaller' is defined as: newsize <=
  100  * oldsize / 2^n, where REALLOC_FRACTION defines the value of 'n'.
  101  */
  102 #ifndef REALLOC_FRACTION
  103 #define REALLOC_FRACTION        1       /* new block if <= half the size */
  104 #endif
  105 
  106 /*
  107  * Centrally define some common malloc types.
  108  */
  109 MALLOC_DEFINE(M_CACHE, "cache", "Various Dynamically allocated caches");
  110 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
  111 MALLOC_DEFINE(M_TEMP, "temp", "misc temporary data buffers");
  112 
  113 MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
  114 MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
  115 
  116 static void kmeminit(void *);
  117 SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_FIRST, kmeminit, NULL);
  118 
  119 static MALLOC_DEFINE(M_FREE, "free", "should be on free list");
  120 
  121 static struct malloc_type *kmemstatistics;
  122 static vm_offset_t kmembase;
  123 static vm_offset_t kmemlimit;
  124 static int kmemcount;
  125 
  126 #define KMEM_ZSHIFT     4
  127 #define KMEM_ZBASE      16
  128 #define KMEM_ZMASK      (KMEM_ZBASE - 1)
  129 
  130 #define KMEM_ZMAX       PAGE_SIZE
  131 #define KMEM_ZSIZE      (KMEM_ZMAX >> KMEM_ZSHIFT)
  132 static u_int8_t kmemsize[KMEM_ZSIZE + 1];
  133 
  134 /*
  135  * Small malloc(9) memory allocations are allocated from a set of UMA buckets
  136  * of various sizes.
  137  *
  138  * XXX: The comment here used to read "These won't be powers of two for
  139  * long."  It's possible that a significant amount of wasted memory could be
  140  * recovered by tuning the sizes of these buckets.
  141  */
  142 struct {
  143         int kz_size;
  144         char *kz_name;
  145         uma_zone_t kz_zone;
  146 } kmemzones[] = {
  147         {16, "16", NULL},
  148         {32, "32", NULL},
  149         {64, "64", NULL},
  150         {128, "128", NULL},
  151         {256, "256", NULL},
  152         {512, "512", NULL},
  153         {1024, "1024", NULL},
  154         {2048, "2048", NULL},
  155         {4096, "4096", NULL},
  156 #if PAGE_SIZE > 4096
  157         {8192, "8192", NULL},
  158 #if PAGE_SIZE > 8192
  159         {16384, "16384", NULL},
  160 #if PAGE_SIZE > 16384
  161         {32768, "32768", NULL},
  162 #if PAGE_SIZE > 32768
  163         {65536, "65536", NULL},
  164 #if PAGE_SIZE > 65536
  165 #error  "Unsupported PAGE_SIZE"
  166 #endif  /* 65536 */
  167 #endif  /* 32768 */
  168 #endif  /* 16384 */
  169 #endif  /* 8192 */
  170 #endif  /* 4096 */
  171         {0, NULL},
  172 };
  173 
  174 /*
  175  * Zone to allocate malloc type descriptions from.  For ABI reasons, memory
  176  * types are described by a data structure passed by the declaring code, but
  177  * the malloc(9) implementation has its own data structure describing the
  178  * type and statistics.  This permits the malloc(9)-internal data structures
  179  * to be modified without breaking binary-compiled kernel modules that
  180  * declare malloc types.
  181  */
  182 static uma_zone_t mt_zone;
  183 
  184 u_long vm_kmem_size;
  185 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size, CTLFLAG_RDTUN, &vm_kmem_size, 0,
  186     "Size of kernel memory");
  187 
  188 static u_long vm_kmem_size_min;
  189 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_min, CTLFLAG_RDTUN, &vm_kmem_size_min, 0,
  190     "Minimum size of kernel memory");
  191 
  192 static u_long vm_kmem_size_max;
  193 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_max, CTLFLAG_RDTUN, &vm_kmem_size_max, 0,
  194     "Maximum size of kernel memory");
  195 
  196 static u_int vm_kmem_size_scale;
  197 SYSCTL_UINT(_vm, OID_AUTO, kmem_size_scale, CTLFLAG_RDTUN, &vm_kmem_size_scale, 0,
  198     "Scale factor for kernel memory size");
  199 
  200 static int sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS);
  201 SYSCTL_PROC(_vm, OID_AUTO, kmem_map_size,
  202     CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
  203     sysctl_kmem_map_size, "LU", "Current kmem_map allocation size");
  204 
  205 static int sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS);
  206 SYSCTL_PROC(_vm, OID_AUTO, kmem_map_free,
  207     CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
  208     sysctl_kmem_map_free, "LU", "Largest contiguous free range in kmem_map");
  209 
  210 /*
  211  * The malloc_mtx protects the kmemstatistics linked list.
  212  */
  213 struct mtx malloc_mtx;
  214 
  215 #ifdef MALLOC_PROFILE
  216 uint64_t krequests[KMEM_ZSIZE + 1];
  217 
  218 static int sysctl_kern_mprof(SYSCTL_HANDLER_ARGS);
  219 #endif
  220 
  221 static int sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS);
  222 
  223 /*
  224  * time_uptime of the last malloc(9) failure (induced or real).
  225  */
  226 static time_t t_malloc_fail;
  227 
  228 /*
  229  * malloc(9) fault injection -- cause malloc failures every (n) mallocs when
  230  * the caller specifies M_NOWAIT.  If set to 0, no failures are caused.
  231  */
  232 #ifdef MALLOC_MAKE_FAILURES
  233 SYSCTL_NODE(_debug, OID_AUTO, malloc, CTLFLAG_RD, 0,
  234     "Kernel malloc debugging options");
  235 
  236 static int malloc_failure_rate;
  237 static int malloc_nowait_count;
  238 static int malloc_failure_count;
  239 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_rate, CTLFLAG_RW,
  240     &malloc_failure_rate, 0, "Every (n) mallocs with M_NOWAIT will fail");
  241 TUNABLE_INT("debug.malloc.failure_rate", &malloc_failure_rate);
  242 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_count, CTLFLAG_RD,
  243     &malloc_failure_count, 0, "Number of imposed M_NOWAIT malloc failures");
  244 #endif
  245 
  246 static int
  247 sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS)
  248 {
  249         u_long size;
  250 
  251         size = kmem_map->size;
  252         return (sysctl_handle_long(oidp, &size, 0, req));
  253 }
  254 
  255 static int
  256 sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS)
  257 {
  258         u_long size;
  259 
  260         vm_map_lock_read(kmem_map);
  261         size = kmem_map->root != NULL ?
  262             kmem_map->root->max_free : kmem_map->size;
  263         vm_map_unlock_read(kmem_map);
  264         return (sysctl_handle_long(oidp, &size, 0, req));
  265 }
  266 
  267 int
  268 malloc_last_fail(void)
  269 {
  270 
  271         return (time_uptime - t_malloc_fail);
  272 }
  273 
  274 /*
  275  * An allocation has succeeded -- update malloc type statistics for the
  276  * amount of bucket size.  Occurs within a critical section so that the
  277  * thread isn't preempted and doesn't migrate while updating per-PCU
  278  * statistics.
  279  */
  280 static void
  281 malloc_type_zone_allocated(struct malloc_type *mtp, unsigned long size,
  282     int zindx)
  283 {
  284         struct malloc_type_internal *mtip;
  285         struct malloc_type_stats *mtsp;
  286 
  287         critical_enter();
  288         mtip = mtp->ks_handle;
  289         mtsp = &mtip->mti_stats[curcpu];
  290         if (size > 0) {
  291                 mtsp->mts_memalloced += size;
  292                 mtsp->mts_numallocs++;
  293         }
  294         if (zindx != -1)
  295                 mtsp->mts_size |= 1 << zindx;
  296 
  297 #ifdef KDTRACE_HOOKS
  298         if (dtrace_malloc_probe != NULL) {
  299                 uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_MALLOC];
  300                 if (probe_id != 0)
  301                         (dtrace_malloc_probe)(probe_id,
  302                             (uintptr_t) mtp, (uintptr_t) mtip,
  303                             (uintptr_t) mtsp, size, zindx);
  304         }
  305 #endif
  306 
  307         critical_exit();
  308 }
  309 
  310 void
  311 malloc_type_allocated(struct malloc_type *mtp, unsigned long size)
  312 {
  313 
  314         if (size > 0)
  315                 malloc_type_zone_allocated(mtp, size, -1);
  316 }
  317 
  318 /*
  319  * A free operation has occurred -- update malloc type statistics for the
  320  * amount of the bucket size.  Occurs within a critical section so that the
  321  * thread isn't preempted and doesn't migrate while updating per-CPU
  322  * statistics.
  323  */
  324 void
  325 malloc_type_freed(struct malloc_type *mtp, unsigned long size)
  326 {
  327         struct malloc_type_internal *mtip;
  328         struct malloc_type_stats *mtsp;
  329 
  330         critical_enter();
  331         mtip = mtp->ks_handle;
  332         mtsp = &mtip->mti_stats[curcpu];
  333         mtsp->mts_memfreed += size;
  334         mtsp->mts_numfrees++;
  335 
  336 #ifdef KDTRACE_HOOKS
  337         if (dtrace_malloc_probe != NULL) {
  338                 uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_FREE];
  339                 if (probe_id != 0)
  340                         (dtrace_malloc_probe)(probe_id,
  341                             (uintptr_t) mtp, (uintptr_t) mtip,
  342                             (uintptr_t) mtsp, size, 0);
  343         }
  344 #endif
  345 
  346         critical_exit();
  347 }
  348 
  349 /*
  350  *      malloc:
  351  *
  352  *      Allocate a block of memory.
  353  *
  354  *      If M_NOWAIT is set, this routine will not block and return NULL if
  355  *      the allocation fails.
  356  */
  357 void *
  358 malloc(unsigned long size, struct malloc_type *mtp, int flags)
  359 {
  360         int indx;
  361         caddr_t va;
  362         uma_zone_t zone;
  363 #if defined(DIAGNOSTIC) || defined(DEBUG_REDZONE)
  364         unsigned long osize = size;
  365 #endif
  366 
  367 #ifdef INVARIANTS
  368         KASSERT(mtp->ks_magic == M_MAGIC, ("malloc: bad malloc type magic"));
  369         /*
  370          * Check that exactly one of M_WAITOK or M_NOWAIT is specified.
  371          */
  372         indx = flags & (M_WAITOK | M_NOWAIT);
  373         if (indx != M_NOWAIT && indx != M_WAITOK) {
  374                 static  struct timeval lasterr;
  375                 static  int curerr, once;
  376                 if (once == 0 && ppsratecheck(&lasterr, &curerr, 1)) {
  377                         printf("Bad malloc flags: %x\n", indx);
  378                         kdb_backtrace();
  379                         flags |= M_WAITOK;
  380                         once++;
  381                 }
  382         }
  383 #endif
  384 #ifdef MALLOC_MAKE_FAILURES
  385         if ((flags & M_NOWAIT) && (malloc_failure_rate != 0)) {
  386                 atomic_add_int(&malloc_nowait_count, 1);
  387                 if ((malloc_nowait_count % malloc_failure_rate) == 0) {
  388                         atomic_add_int(&malloc_failure_count, 1);
  389                         t_malloc_fail = time_uptime;
  390                         return (NULL);
  391                 }
  392         }
  393 #endif
  394         if (flags & M_WAITOK)
  395                 KASSERT(curthread->td_intr_nesting_level == 0,
  396                    ("malloc(M_WAITOK) in interrupt context"));
  397 
  398 #ifdef DEBUG_MEMGUARD
  399         if (memguard_cmp(mtp, size)) {
  400                 va = memguard_alloc(size, flags);
  401                 if (va != NULL)
  402                         return (va);
  403                 /* This is unfortunate but should not be fatal. */
  404         }
  405 #endif
  406 
  407 #ifdef DEBUG_REDZONE
  408         size = redzone_size_ntor(size);
  409 #endif
  410 
  411         if (size <= KMEM_ZMAX) {
  412                 if (size & KMEM_ZMASK)
  413                         size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
  414                 indx = kmemsize[size >> KMEM_ZSHIFT];
  415                 zone = kmemzones[indx].kz_zone;
  416 #ifdef MALLOC_PROFILE
  417                 krequests[size >> KMEM_ZSHIFT]++;
  418 #endif
  419                 va = uma_zalloc(zone, flags);
  420                 if (va != NULL)
  421                         size = zone->uz_size;
  422                 malloc_type_zone_allocated(mtp, va == NULL ? 0 : size, indx);
  423         } else {
  424                 size = roundup(size, PAGE_SIZE);
  425                 zone = NULL;
  426                 va = uma_large_malloc(size, flags);
  427                 malloc_type_allocated(mtp, va == NULL ? 0 : size);
  428         }
  429         if (flags & M_WAITOK)
  430                 KASSERT(va != NULL, ("malloc(M_WAITOK) returned NULL"));
  431         else if (va == NULL)
  432                 t_malloc_fail = time_uptime;
  433 #ifdef DIAGNOSTIC
  434         if (va != NULL && !(flags & M_ZERO)) {
  435                 memset(va, 0x70, osize);
  436         }
  437 #endif
  438 #ifdef DEBUG_REDZONE
  439         if (va != NULL)
  440                 va = redzone_setup(va, osize);
  441 #endif
  442         return ((void *) va);
  443 }
  444 
  445 /*
  446  *      free:
  447  *
  448  *      Free a block of memory allocated by malloc.
  449  *
  450  *      This routine may not block.
  451  */
  452 void
  453 free(void *addr, struct malloc_type *mtp)
  454 {
  455         uma_slab_t slab;
  456         u_long size;
  457 
  458         KASSERT(mtp->ks_magic == M_MAGIC, ("free: bad malloc type magic"));
  459 
  460         /* free(NULL, ...) does nothing */
  461         if (addr == NULL)
  462                 return;
  463 
  464 #ifdef DEBUG_MEMGUARD
  465         if (is_memguard_addr(addr)) {
  466                 memguard_free(addr);
  467                 return;
  468         }
  469 #endif
  470 
  471 #ifdef DEBUG_REDZONE
  472         redzone_check(addr);
  473         addr = redzone_addr_ntor(addr);
  474 #endif
  475 
  476         slab = vtoslab((vm_offset_t)addr & (~UMA_SLAB_MASK));
  477 
  478         if (slab == NULL)
  479                 panic("free: address %p(%p) has not been allocated.\n",
  480                     addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
  481 
  482 
  483         if (!(slab->us_flags & UMA_SLAB_MALLOC)) {
  484 #ifdef INVARIANTS
  485                 struct malloc_type **mtpp = addr;
  486 #endif
  487                 size = slab->us_keg->uk_size;
  488 #ifdef INVARIANTS
  489                 /*
  490                  * Cache a pointer to the malloc_type that most recently freed
  491                  * this memory here.  This way we know who is most likely to
  492                  * have stepped on it later.
  493                  *
  494                  * This code assumes that size is a multiple of 8 bytes for
  495                  * 64 bit machines
  496                  */
  497                 mtpp = (struct malloc_type **)
  498                     ((unsigned long)mtpp & ~UMA_ALIGN_PTR);
  499                 mtpp += (size - sizeof(struct malloc_type *)) /
  500                     sizeof(struct malloc_type *);
  501                 *mtpp = mtp;
  502 #endif
  503                 uma_zfree_arg(LIST_FIRST(&slab->us_keg->uk_zones), addr, slab);
  504         } else {
  505                 size = slab->us_size;
  506                 uma_large_free(slab);
  507         }
  508         malloc_type_freed(mtp, size);
  509 }
  510 
  511 /*
  512  *      realloc: change the size of a memory block
  513  */
  514 void *
  515 realloc(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
  516 {
  517         uma_slab_t slab;
  518         unsigned long alloc;
  519         void *newaddr;
  520 
  521         KASSERT(mtp->ks_magic == M_MAGIC,
  522             ("realloc: bad malloc type magic"));
  523 
  524         /* realloc(NULL, ...) is equivalent to malloc(...) */
  525         if (addr == NULL)
  526                 return (malloc(size, mtp, flags));
  527 
  528         /*
  529          * XXX: Should report free of old memory and alloc of new memory to
  530          * per-CPU stats.
  531          */
  532 
  533 #ifdef DEBUG_MEMGUARD
  534         if (is_memguard_addr(addr))
  535                 return (memguard_realloc(addr, size, mtp, flags));
  536 #endif
  537 
  538 #ifdef DEBUG_REDZONE
  539         slab = NULL;
  540         alloc = redzone_get_size(addr);
  541 #else
  542         slab = vtoslab((vm_offset_t)addr & ~(UMA_SLAB_MASK));
  543 
  544         /* Sanity check */
  545         KASSERT(slab != NULL,
  546             ("realloc: address %p out of range", (void *)addr));
  547 
  548         /* Get the size of the original block */
  549         if (!(slab->us_flags & UMA_SLAB_MALLOC))
  550                 alloc = slab->us_keg->uk_size;
  551         else
  552                 alloc = slab->us_size;
  553 
  554         /* Reuse the original block if appropriate */
  555         if (size <= alloc
  556             && (size > (alloc >> REALLOC_FRACTION) || alloc == MINALLOCSIZE))
  557                 return (addr);
  558 #endif /* !DEBUG_REDZONE */
  559 
  560         /* Allocate a new, bigger (or smaller) block */
  561         if ((newaddr = malloc(size, mtp, flags)) == NULL)
  562                 return (NULL);
  563 
  564         /* Copy over original contents */
  565         bcopy(addr, newaddr, min(size, alloc));
  566         free(addr, mtp);
  567         return (newaddr);
  568 }
  569 
  570 /*
  571  *      reallocf: same as realloc() but free memory on failure.
  572  */
  573 void *
  574 reallocf(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
  575 {
  576         void *mem;
  577 
  578         if ((mem = realloc(addr, size, mtp, flags)) == NULL)
  579                 free(addr, mtp);
  580         return (mem);
  581 }
  582 
  583 /*
  584  * Initialize the kernel memory allocator
  585  */
  586 /* ARGSUSED*/
  587 static void
  588 kmeminit(void *dummy)
  589 {
  590         u_int8_t indx;
  591         u_long mem_size, tmp;
  592         int i;
  593  
  594         mtx_init(&malloc_mtx, "malloc", NULL, MTX_DEF);
  595 
  596         /*
  597          * Try to auto-tune the kernel memory size, so that it is
  598          * more applicable for a wider range of machine sizes.
  599          * On an X86, a VM_KMEM_SIZE_SCALE value of 4 is good, while
  600          * a VM_KMEM_SIZE of 12MB is a fair compromise.  The
  601          * VM_KMEM_SIZE_MAX is dependent on the maximum KVA space
  602          * available, and on an X86 with a total KVA space of 256MB,
  603          * try to keep VM_KMEM_SIZE_MAX at 80MB or below.
  604          *
  605          * Note that the kmem_map is also used by the zone allocator,
  606          * so make sure that there is enough space.
  607          */
  608         vm_kmem_size = VM_KMEM_SIZE + nmbclusters * PAGE_SIZE;
  609         mem_size = cnt.v_page_count;
  610 
  611 #if defined(VM_KMEM_SIZE_SCALE)
  612         vm_kmem_size_scale = VM_KMEM_SIZE_SCALE;
  613 #endif
  614         TUNABLE_INT_FETCH("vm.kmem_size_scale", &vm_kmem_size_scale);
  615         if (vm_kmem_size_scale > 0 &&
  616             (mem_size / vm_kmem_size_scale) > (vm_kmem_size / PAGE_SIZE))
  617                 vm_kmem_size = (mem_size / vm_kmem_size_scale) * PAGE_SIZE;
  618 
  619 #if defined(VM_KMEM_SIZE_MIN)
  620         vm_kmem_size_min = VM_KMEM_SIZE_MIN;
  621 #endif
  622         TUNABLE_ULONG_FETCH("vm.kmem_size_min", &vm_kmem_size_min);
  623         if (vm_kmem_size_min > 0 && vm_kmem_size < vm_kmem_size_min) {
  624                 vm_kmem_size = vm_kmem_size_min;
  625         }
  626 
  627 #if defined(VM_KMEM_SIZE_MAX)
  628         vm_kmem_size_max = VM_KMEM_SIZE_MAX;
  629 #endif
  630         TUNABLE_ULONG_FETCH("vm.kmem_size_max", &vm_kmem_size_max);
  631         if (vm_kmem_size_max > 0 && vm_kmem_size >= vm_kmem_size_max)
  632                 vm_kmem_size = vm_kmem_size_max;
  633 
  634         /* Allow final override from the kernel environment */
  635         TUNABLE_ULONG_FETCH("vm.kmem_size", &vm_kmem_size);
  636 
  637         /*
  638          * Limit kmem virtual size to twice the physical memory.
  639          * This allows for kmem map sparseness, but limits the size
  640          * to something sane. Be careful to not overflow the 32bit
  641          * ints while doing the check.
  642          */
  643         if (((vm_kmem_size / 2) / PAGE_SIZE) > cnt.v_page_count)
  644                 vm_kmem_size = 2 * cnt.v_page_count * PAGE_SIZE;
  645 
  646         /*
  647          * Tune settings based on the kmem map's size at this time.
  648          */
  649         init_param3(vm_kmem_size / PAGE_SIZE);
  650 
  651 #ifdef DEBUG_MEMGUARD
  652         tmp = memguard_fudge(vm_kmem_size, vm_kmem_size_max);
  653 #else
  654         tmp = vm_kmem_size;
  655 #endif
  656         kmem_map = kmem_suballoc(kernel_map, &kmembase, &kmemlimit,
  657             tmp, TRUE);
  658         kmem_map->system_map = 1;
  659 
  660 #ifdef DEBUG_MEMGUARD
  661         /*
  662          * Initialize MemGuard if support compiled in.  MemGuard is a
  663          * replacement allocator used for detecting tamper-after-free
  664          * scenarios as they occur.  It is only used for debugging.
  665          */
  666         memguard_init(kmem_map);
  667 #endif
  668 
  669         uma_startup2();
  670 
  671         mt_zone = uma_zcreate("mt_zone", sizeof(struct malloc_type_internal),
  672 #ifdef INVARIANTS
  673             mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
  674 #else
  675             NULL, NULL, NULL, NULL,
  676 #endif
  677             UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
  678         for (i = 0, indx = 0; kmemzones[indx].kz_size != 0; indx++) {
  679                 int size = kmemzones[indx].kz_size;
  680                 char *name = kmemzones[indx].kz_name;
  681 
  682                 kmemzones[indx].kz_zone = uma_zcreate(name, size,
  683 #ifdef INVARIANTS
  684                     mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
  685 #else
  686                     NULL, NULL, NULL, NULL,
  687 #endif
  688                     UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
  689                     
  690                 for (;i <= size; i+= KMEM_ZBASE)
  691                         kmemsize[i >> KMEM_ZSHIFT] = indx;
  692                 
  693         }
  694 }
  695 
  696 void
  697 malloc_init(void *data)
  698 {
  699         struct malloc_type_internal *mtip;
  700         struct malloc_type *mtp;
  701 
  702         KASSERT(cnt.v_page_count != 0, ("malloc_register before vm_init"));
  703 
  704         mtp = data;
  705         if (mtp->ks_magic != M_MAGIC)
  706                 panic("malloc_init: bad malloc type magic");
  707 
  708         mtip = uma_zalloc(mt_zone, M_WAITOK | M_ZERO);
  709         mtp->ks_handle = mtip;
  710 
  711         mtx_lock(&malloc_mtx);
  712         mtp->ks_next = kmemstatistics;
  713         kmemstatistics = mtp;
  714         kmemcount++;
  715         mtx_unlock(&malloc_mtx);
  716 }
  717 
  718 void
  719 malloc_uninit(void *data)
  720 {
  721         struct malloc_type_internal *mtip;
  722         struct malloc_type_stats *mtsp;
  723         struct malloc_type *mtp, *temp;
  724         uma_slab_t slab;
  725         long temp_allocs, temp_bytes;
  726         int i;
  727 
  728         mtp = data;
  729         KASSERT(mtp->ks_magic == M_MAGIC,
  730             ("malloc_uninit: bad malloc type magic"));
  731         KASSERT(mtp->ks_handle != NULL, ("malloc_deregister: cookie NULL"));
  732 
  733         mtx_lock(&malloc_mtx);
  734         mtip = mtp->ks_handle;
  735         mtp->ks_handle = NULL;
  736         if (mtp != kmemstatistics) {
  737                 for (temp = kmemstatistics; temp != NULL;
  738                     temp = temp->ks_next) {
  739                         if (temp->ks_next == mtp) {
  740                                 temp->ks_next = mtp->ks_next;
  741                                 break;
  742                         }
  743                 }
  744                 KASSERT(temp,
  745                     ("malloc_uninit: type '%s' not found", mtp->ks_shortdesc));
  746         } else
  747                 kmemstatistics = mtp->ks_next;
  748         kmemcount--;
  749         mtx_unlock(&malloc_mtx);
  750 
  751         /*
  752          * Look for memory leaks.
  753          */
  754         temp_allocs = temp_bytes = 0;
  755         for (i = 0; i < MAXCPU; i++) {
  756                 mtsp = &mtip->mti_stats[i];
  757                 temp_allocs += mtsp->mts_numallocs;
  758                 temp_allocs -= mtsp->mts_numfrees;
  759                 temp_bytes += mtsp->mts_memalloced;
  760                 temp_bytes -= mtsp->mts_memfreed;
  761         }
  762         if (temp_allocs > 0 || temp_bytes > 0) {
  763                 printf("Warning: memory type %s leaked memory on destroy "
  764                     "(%ld allocations, %ld bytes leaked).\n", mtp->ks_shortdesc,
  765                     temp_allocs, temp_bytes);
  766         }
  767 
  768         slab = vtoslab((vm_offset_t) mtip & (~UMA_SLAB_MASK));
  769         uma_zfree_arg(mt_zone, mtip, slab);
  770 }
  771 
  772 struct malloc_type *
  773 malloc_desc2type(const char *desc)
  774 {
  775         struct malloc_type *mtp;
  776 
  777         mtx_assert(&malloc_mtx, MA_OWNED);
  778         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
  779                 if (strcmp(mtp->ks_shortdesc, desc) == 0)
  780                         return (mtp);
  781         }
  782         return (NULL);
  783 }
  784 
  785 static int
  786 sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS)
  787 {
  788         struct malloc_type_stream_header mtsh;
  789         struct malloc_type_internal *mtip;
  790         struct malloc_type_header mth;
  791         struct malloc_type *mtp;
  792         int buflen, count, error, i;
  793         struct sbuf sbuf;
  794         char *buffer;
  795 
  796         mtx_lock(&malloc_mtx);
  797 restart:
  798         mtx_assert(&malloc_mtx, MA_OWNED);
  799         count = kmemcount;
  800         mtx_unlock(&malloc_mtx);
  801         buflen = sizeof(mtsh) + count * (sizeof(mth) +
  802             sizeof(struct malloc_type_stats) * MAXCPU) + 1;
  803         buffer = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
  804         mtx_lock(&malloc_mtx);
  805         if (count < kmemcount) {
  806                 free(buffer, M_TEMP);
  807                 goto restart;
  808         }
  809 
  810         sbuf_new(&sbuf, buffer, buflen, SBUF_FIXEDLEN);
  811 
  812         /*
  813          * Insert stream header.
  814          */
  815         bzero(&mtsh, sizeof(mtsh));
  816         mtsh.mtsh_version = MALLOC_TYPE_STREAM_VERSION;
  817         mtsh.mtsh_maxcpus = MAXCPU;
  818         mtsh.mtsh_count = kmemcount;
  819         if (sbuf_bcat(&sbuf, &mtsh, sizeof(mtsh)) < 0) {
  820                 mtx_unlock(&malloc_mtx);
  821                 error = ENOMEM;
  822                 goto out;
  823         }
  824 
  825         /*
  826          * Insert alternating sequence of type headers and type statistics.
  827          */
  828         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
  829                 mtip = (struct malloc_type_internal *)mtp->ks_handle;
  830 
  831                 /*
  832                  * Insert type header.
  833                  */
  834                 bzero(&mth, sizeof(mth));
  835                 strlcpy(mth.mth_name, mtp->ks_shortdesc, MALLOC_MAX_NAME);
  836                 if (sbuf_bcat(&sbuf, &mth, sizeof(mth)) < 0) {
  837                         mtx_unlock(&malloc_mtx);
  838                         error = ENOMEM;
  839                         goto out;
  840                 }
  841 
  842                 /*
  843                  * Insert type statistics for each CPU.
  844                  */
  845                 for (i = 0; i < MAXCPU; i++) {
  846                         if (sbuf_bcat(&sbuf, &mtip->mti_stats[i],
  847                             sizeof(mtip->mti_stats[i])) < 0) {
  848                                 mtx_unlock(&malloc_mtx);
  849                                 error = ENOMEM;
  850                                 goto out;
  851                         }
  852                 }
  853         }
  854         mtx_unlock(&malloc_mtx);
  855         sbuf_finish(&sbuf);
  856         error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
  857 out:
  858         sbuf_delete(&sbuf);
  859         free(buffer, M_TEMP);
  860         return (error);
  861 }
  862 
  863 SYSCTL_PROC(_kern, OID_AUTO, malloc_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
  864     0, 0, sysctl_kern_malloc_stats, "s,malloc_type_ustats",
  865     "Return malloc types");
  866 
  867 SYSCTL_INT(_kern, OID_AUTO, malloc_count, CTLFLAG_RD, &kmemcount, 0,
  868     "Count of kernel malloc types");
  869 
  870 void
  871 malloc_type_list(malloc_type_list_func_t *func, void *arg)
  872 {
  873         struct malloc_type *mtp, **bufmtp;
  874         int count, i;
  875         size_t buflen;
  876 
  877         mtx_lock(&malloc_mtx);
  878 restart:
  879         mtx_assert(&malloc_mtx, MA_OWNED);
  880         count = kmemcount;
  881         mtx_unlock(&malloc_mtx);
  882 
  883         buflen = sizeof(struct malloc_type *) * count;
  884         bufmtp = malloc(buflen, M_TEMP, M_WAITOK);
  885 
  886         mtx_lock(&malloc_mtx);
  887 
  888         if (count < kmemcount) {
  889                 free(bufmtp, M_TEMP);
  890                 goto restart;
  891         }
  892 
  893         for (mtp = kmemstatistics, i = 0; mtp != NULL; mtp = mtp->ks_next, i++)
  894                 bufmtp[i] = mtp;
  895 
  896         mtx_unlock(&malloc_mtx);
  897 
  898         for (i = 0; i < count; i++)
  899                 (func)(bufmtp[i], arg);
  900 
  901         free(bufmtp, M_TEMP);
  902 }
  903 
  904 #ifdef DDB
  905 DB_SHOW_COMMAND(malloc, db_show_malloc)
  906 {
  907         struct malloc_type_internal *mtip;
  908         struct malloc_type *mtp;
  909         u_int64_t allocs, frees;
  910         u_int64_t alloced, freed;
  911         int i;
  912 
  913         db_printf("%18s %12s  %12s %12s\n", "Type", "InUse", "MemUse",
  914             "Requests");
  915         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
  916                 mtip = (struct malloc_type_internal *)mtp->ks_handle;
  917                 allocs = 0;
  918                 frees = 0;
  919                 alloced = 0;
  920                 freed = 0;
  921                 for (i = 0; i < MAXCPU; i++) {
  922                         allocs += mtip->mti_stats[i].mts_numallocs;
  923                         frees += mtip->mti_stats[i].mts_numfrees;
  924                         alloced += mtip->mti_stats[i].mts_memalloced;
  925                         freed += mtip->mti_stats[i].mts_memfreed;
  926                 }
  927                 db_printf("%18s %12ju %12juK %12ju\n",
  928                     mtp->ks_shortdesc, allocs - frees,
  929                     (alloced - freed + 1023) / 1024, allocs);
  930         }
  931 }
  932 #endif
  933 
  934 #ifdef MALLOC_PROFILE
  935 
  936 static int
  937 sysctl_kern_mprof(SYSCTL_HANDLER_ARGS)
  938 {
  939         int linesize = 64;
  940         struct sbuf sbuf;
  941         uint64_t count;
  942         uint64_t waste;
  943         uint64_t mem;
  944         int bufsize;
  945         int error;
  946         char *buf;
  947         int rsize;
  948         int size;
  949         int i;
  950 
  951         bufsize = linesize * (KMEM_ZSIZE + 1);
  952         bufsize += 128;         /* For the stats line */
  953         bufsize += 128;         /* For the banner line */
  954         waste = 0;
  955         mem = 0;
  956 
  957         buf = malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO);
  958         sbuf_new(&sbuf, buf, bufsize, SBUF_FIXEDLEN);
  959         sbuf_printf(&sbuf, 
  960             "\n  Size                    Requests  Real Size\n");
  961         for (i = 0; i < KMEM_ZSIZE; i++) {
  962                 size = i << KMEM_ZSHIFT;
  963                 rsize = kmemzones[kmemsize[i]].kz_size;
  964                 count = (long long unsigned)krequests[i];
  965 
  966                 sbuf_printf(&sbuf, "%6d%28llu%11d\n", size,
  967                     (unsigned long long)count, rsize);
  968 
  969                 if ((rsize * count) > (size * count))
  970                         waste += (rsize * count) - (size * count);
  971                 mem += (rsize * count);
  972         }
  973         sbuf_printf(&sbuf,
  974             "\nTotal memory used:\t%30llu\nTotal Memory wasted:\t%30llu\n",
  975             (unsigned long long)mem, (unsigned long long)waste);
  976         sbuf_finish(&sbuf);
  977 
  978         error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
  979 
  980         sbuf_delete(&sbuf);
  981         free(buf, M_TEMP);
  982         return (error);
  983 }
  984 
  985 SYSCTL_OID(_kern, OID_AUTO, mprof, CTLTYPE_STRING|CTLFLAG_RD,
  986     NULL, 0, sysctl_kern_mprof, "A", "Malloc Profiling");
  987 #endif /* MALLOC_PROFILE */

Cache object: 98d9d690f521c547f266637db774a3ac


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