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) 2005-2006 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("$FreeBSD$");
   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_int vm_kmem_size;
  185 SYSCTL_UINT(_vm, OID_AUTO, kmem_size, CTLFLAG_RD, &vm_kmem_size, 0,
  186     "Size of kernel memory");
  187 
  188 u_int vm_kmem_size_min;
  189 SYSCTL_UINT(_vm, OID_AUTO, kmem_size_min, CTLFLAG_RD, &vm_kmem_size_min, 0,
  190     "Minimum size of kernel memory");
  191 
  192 u_int vm_kmem_size_max;
  193 SYSCTL_UINT(_vm, OID_AUTO, kmem_size_max, CTLFLAG_RD, &vm_kmem_size_max, 0,
  194     "Maximum size of kernel memory");
  195 
  196 u_int vm_kmem_size_scale;
  197 SYSCTL_UINT(_vm, OID_AUTO, kmem_size_scale, CTLFLAG_RD, &vm_kmem_size_scale, 0,
  198     "Scale factor for kernel memory size");
  199 
  200 /*
  201  * The malloc_mtx protects the kmemstatistics linked list.
  202  */
  203 struct mtx malloc_mtx;
  204 
  205 #ifdef MALLOC_PROFILE
  206 uint64_t krequests[KMEM_ZSIZE + 1];
  207 
  208 static int sysctl_kern_mprof(SYSCTL_HANDLER_ARGS);
  209 #endif
  210 
  211 static int sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS);
  212 
  213 /*
  214  * time_uptime of the last malloc(9) failure (induced or real).
  215  */
  216 static time_t t_malloc_fail;
  217 
  218 /*
  219  * malloc(9) fault injection -- cause malloc failures every (n) mallocs when
  220  * the caller specifies M_NOWAIT.  If set to 0, no failures are caused.
  221  */
  222 #ifdef MALLOC_MAKE_FAILURES
  223 SYSCTL_NODE(_debug, OID_AUTO, malloc, CTLFLAG_RD, 0,
  224     "Kernel malloc debugging options");
  225 
  226 static int malloc_failure_rate;
  227 static int malloc_nowait_count;
  228 static int malloc_failure_count;
  229 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_rate, CTLFLAG_RW,
  230     &malloc_failure_rate, 0, "Every (n) mallocs with M_NOWAIT will fail");
  231 TUNABLE_INT("debug.malloc.failure_rate", &malloc_failure_rate);
  232 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_count, CTLFLAG_RD,
  233     &malloc_failure_count, 0, "Number of imposed M_NOWAIT malloc failures");
  234 #endif
  235 
  236 int
  237 malloc_last_fail(void)
  238 {
  239 
  240         return (time_uptime - t_malloc_fail);
  241 }
  242 
  243 /*
  244  * An allocation has succeeded -- update malloc type statistics for the
  245  * amount of bucket size.  Occurs within a critical section so that the
  246  * thread isn't preempted and doesn't migrate while updating per-PCU
  247  * statistics.
  248  */
  249 static void
  250 malloc_type_zone_allocated(struct malloc_type *mtp, unsigned long size,
  251     int zindx)
  252 {
  253         struct malloc_type_internal *mtip;
  254         struct malloc_type_stats *mtsp;
  255 
  256         critical_enter();
  257         mtip = mtp->ks_handle;
  258         mtsp = &mtip->mti_stats[curcpu];
  259         if (size > 0) {
  260                 mtsp->mts_memalloced += size;
  261                 mtsp->mts_numallocs++;
  262         }
  263         if (zindx != -1)
  264                 mtsp->mts_size |= 1 << zindx;
  265 
  266 #ifdef KDTRACE_HOOKS
  267         if (dtrace_malloc_probe != NULL) {
  268                 uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_MALLOC];
  269                 if (probe_id != 0)
  270                         (dtrace_malloc_probe)(probe_id,
  271                             (uintptr_t) mtp, (uintptr_t) mtip,
  272                             (uintptr_t) mtsp, size, zindx);
  273         }
  274 #endif
  275 
  276         critical_exit();
  277 }
  278 
  279 void
  280 malloc_type_allocated(struct malloc_type *mtp, unsigned long size)
  281 {
  282 
  283         if (size > 0)
  284                 malloc_type_zone_allocated(mtp, size, -1);
  285 }
  286 
  287 /*
  288  * A free operation has occurred -- update malloc type statistics for the
  289  * amount of the bucket size.  Occurs within a critical section so that the
  290  * thread isn't preempted and doesn't migrate while updating per-CPU
  291  * statistics.
  292  */
  293 void
  294 malloc_type_freed(struct malloc_type *mtp, unsigned long size)
  295 {
  296         struct malloc_type_internal *mtip;
  297         struct malloc_type_stats *mtsp;
  298 
  299         critical_enter();
  300         mtip = mtp->ks_handle;
  301         mtsp = &mtip->mti_stats[curcpu];
  302         mtsp->mts_memfreed += size;
  303         mtsp->mts_numfrees++;
  304 
  305 #ifdef KDTRACE_HOOKS
  306         if (dtrace_malloc_probe != NULL) {
  307                 uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_FREE];
  308                 if (probe_id != 0)
  309                         (dtrace_malloc_probe)(probe_id,
  310                             (uintptr_t) mtp, (uintptr_t) mtip,
  311                             (uintptr_t) mtsp, size, 0);
  312         }
  313 #endif
  314 
  315         critical_exit();
  316 }
  317 
  318 /*
  319  *      malloc:
  320  *
  321  *      Allocate a block of memory.
  322  *
  323  *      If M_NOWAIT is set, this routine will not block and return NULL if
  324  *      the allocation fails.
  325  */
  326 void *
  327 malloc(unsigned long size, struct malloc_type *mtp, int flags)
  328 {
  329         int indx;
  330         caddr_t va;
  331         uma_zone_t zone;
  332         uma_keg_t keg;
  333 #if defined(DIAGNOSTIC) || defined(DEBUG_REDZONE)
  334         unsigned long osize = size;
  335 #endif
  336 
  337 #ifdef INVARIANTS
  338         /*
  339          * Check that exactly one of M_WAITOK or M_NOWAIT is specified.
  340          */
  341         indx = flags & (M_WAITOK | M_NOWAIT);
  342         if (indx != M_NOWAIT && indx != M_WAITOK) {
  343                 static  struct timeval lasterr;
  344                 static  int curerr, once;
  345                 if (once == 0 && ppsratecheck(&lasterr, &curerr, 1)) {
  346                         printf("Bad malloc flags: %x\n", indx);
  347                         kdb_backtrace();
  348                         flags |= M_WAITOK;
  349                         once++;
  350                 }
  351         }
  352 #endif
  353 #ifdef MALLOC_MAKE_FAILURES
  354         if ((flags & M_NOWAIT) && (malloc_failure_rate != 0)) {
  355                 atomic_add_int(&malloc_nowait_count, 1);
  356                 if ((malloc_nowait_count % malloc_failure_rate) == 0) {
  357                         atomic_add_int(&malloc_failure_count, 1);
  358                         t_malloc_fail = time_uptime;
  359                         return (NULL);
  360                 }
  361         }
  362 #endif
  363         if (flags & M_WAITOK)
  364                 KASSERT(curthread->td_intr_nesting_level == 0,
  365                    ("malloc(M_WAITOK) in interrupt context"));
  366 
  367 #ifdef DEBUG_MEMGUARD
  368         if (memguard_cmp(mtp))
  369                 return memguard_alloc(size, flags);
  370 #endif
  371 
  372 #ifdef DEBUG_REDZONE
  373         size = redzone_size_ntor(size);
  374 #endif
  375 
  376         if (size <= KMEM_ZMAX) {
  377                 if (size & KMEM_ZMASK)
  378                         size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
  379                 indx = kmemsize[size >> KMEM_ZSHIFT];
  380                 zone = kmemzones[indx].kz_zone;
  381                 keg = zone->uz_keg;
  382 #ifdef MALLOC_PROFILE
  383                 krequests[size >> KMEM_ZSHIFT]++;
  384 #endif
  385                 va = uma_zalloc(zone, flags);
  386                 if (va != NULL)
  387                         size = keg->uk_size;
  388                 malloc_type_zone_allocated(mtp, va == NULL ? 0 : size, indx);
  389         } else {
  390                 size = roundup(size, PAGE_SIZE);
  391                 zone = NULL;
  392                 keg = NULL;
  393                 va = uma_large_malloc(size, flags);
  394                 malloc_type_allocated(mtp, va == NULL ? 0 : size);
  395         }
  396         if (flags & M_WAITOK)
  397                 KASSERT(va != NULL, ("malloc(M_WAITOK) returned NULL"));
  398         else if (va == NULL)
  399                 t_malloc_fail = time_uptime;
  400 #ifdef DIAGNOSTIC
  401         if (va != NULL && !(flags & M_ZERO)) {
  402                 memset(va, 0x70, osize);
  403         }
  404 #endif
  405 #ifdef DEBUG_REDZONE
  406         if (va != NULL)
  407                 va = redzone_setup(va, osize);
  408 #endif
  409         return ((void *) va);
  410 }
  411 
  412 /*
  413  *      free:
  414  *
  415  *      Free a block of memory allocated by malloc.
  416  *
  417  *      This routine may not block.
  418  */
  419 void
  420 free(void *addr, struct malloc_type *mtp)
  421 {
  422         uma_slab_t slab;
  423         u_long size;
  424 
  425         /* free(NULL, ...) does nothing */
  426         if (addr == NULL)
  427                 return;
  428 
  429 #ifdef DEBUG_MEMGUARD
  430         if (memguard_cmp(mtp)) {
  431                 memguard_free(addr);
  432                 return;
  433         }
  434 #endif
  435 
  436 #ifdef DEBUG_REDZONE
  437         redzone_check(addr);
  438         addr = redzone_addr_ntor(addr);
  439 #endif
  440 
  441         size = 0;
  442 
  443         slab = vtoslab((vm_offset_t)addr & (~UMA_SLAB_MASK));
  444 
  445         if (slab == NULL)
  446                 panic("free: address %p(%p) has not been allocated.\n",
  447                     addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
  448 
  449 
  450         if (!(slab->us_flags & UMA_SLAB_MALLOC)) {
  451 #ifdef INVARIANTS
  452                 struct malloc_type **mtpp = addr;
  453 #endif
  454                 size = slab->us_keg->uk_size;
  455 #ifdef INVARIANTS
  456                 /*
  457                  * Cache a pointer to the malloc_type that most recently freed
  458                  * this memory here.  This way we know who is most likely to
  459                  * have stepped on it later.
  460                  *
  461                  * This code assumes that size is a multiple of 8 bytes for
  462                  * 64 bit machines
  463                  */
  464                 mtpp = (struct malloc_type **)
  465                     ((unsigned long)mtpp & ~UMA_ALIGN_PTR);
  466                 mtpp += (size - sizeof(struct malloc_type *)) /
  467                     sizeof(struct malloc_type *);
  468                 *mtpp = mtp;
  469 #endif
  470                 uma_zfree_arg(LIST_FIRST(&slab->us_keg->uk_zones), addr, slab);
  471         } else {
  472                 size = slab->us_size;
  473                 uma_large_free(slab);
  474         }
  475         malloc_type_freed(mtp, size);
  476 }
  477 
  478 /*
  479  *      realloc: change the size of a memory block
  480  */
  481 void *
  482 realloc(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
  483 {
  484         uma_slab_t slab;
  485         unsigned long alloc;
  486         void *newaddr;
  487 
  488         /* realloc(NULL, ...) is equivalent to malloc(...) */
  489         if (addr == NULL)
  490                 return (malloc(size, mtp, flags));
  491 
  492         /*
  493          * XXX: Should report free of old memory and alloc of new memory to
  494          * per-CPU stats.
  495          */
  496 
  497 #ifdef DEBUG_MEMGUARD
  498 if (memguard_cmp(mtp)) {
  499         slab = NULL;
  500         alloc = size;
  501 } else {
  502 #endif
  503 
  504 #ifdef DEBUG_REDZONE
  505         slab = NULL;
  506         alloc = redzone_get_size(addr);
  507 #else
  508         slab = vtoslab((vm_offset_t)addr & ~(UMA_SLAB_MASK));
  509 
  510         /* Sanity check */
  511         KASSERT(slab != NULL,
  512             ("realloc: address %p out of range", (void *)addr));
  513 
  514         /* Get the size of the original block */
  515         if (!(slab->us_flags & UMA_SLAB_MALLOC))
  516                 alloc = slab->us_keg->uk_size;
  517         else
  518                 alloc = slab->us_size;
  519 
  520         /* Reuse the original block if appropriate */
  521         if (size <= alloc
  522             && (size > (alloc >> REALLOC_FRACTION) || alloc == MINALLOCSIZE))
  523                 return (addr);
  524 #endif /* !DEBUG_REDZONE */
  525 
  526 #ifdef DEBUG_MEMGUARD
  527 }
  528 #endif
  529 
  530         /* Allocate a new, bigger (or smaller) block */
  531         if ((newaddr = malloc(size, mtp, flags)) == NULL)
  532                 return (NULL);
  533 
  534         /* Copy over original contents */
  535         bcopy(addr, newaddr, min(size, alloc));
  536         free(addr, mtp);
  537         return (newaddr);
  538 }
  539 
  540 /*
  541  *      reallocf: same as realloc() but free memory on failure.
  542  */
  543 void *
  544 reallocf(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
  545 {
  546         void *mem;
  547 
  548         if ((mem = realloc(addr, size, mtp, flags)) == NULL)
  549                 free(addr, mtp);
  550         return (mem);
  551 }
  552 
  553 /*
  554  * Initialize the kernel memory allocator
  555  */
  556 /* ARGSUSED*/
  557 static void
  558 kmeminit(void *dummy)
  559 {
  560         u_int8_t indx;
  561         u_long mem_size;
  562         int i;
  563  
  564         mtx_init(&malloc_mtx, "malloc", NULL, MTX_DEF);
  565 
  566         /*
  567          * Try to auto-tune the kernel memory size, so that it is
  568          * more applicable for a wider range of machine sizes.
  569          * On an X86, a VM_KMEM_SIZE_SCALE value of 4 is good, while
  570          * a VM_KMEM_SIZE of 12MB is a fair compromise.  The
  571          * VM_KMEM_SIZE_MAX is dependent on the maximum KVA space
  572          * available, and on an X86 with a total KVA space of 256MB,
  573          * try to keep VM_KMEM_SIZE_MAX at 80MB or below.
  574          *
  575          * Note that the kmem_map is also used by the zone allocator,
  576          * so make sure that there is enough space.
  577          */
  578         vm_kmem_size = VM_KMEM_SIZE + nmbclusters * PAGE_SIZE;
  579         mem_size = cnt.v_page_count;
  580 
  581 #if defined(VM_KMEM_SIZE_SCALE)
  582         vm_kmem_size_scale = VM_KMEM_SIZE_SCALE;
  583 #endif
  584         TUNABLE_INT_FETCH("vm.kmem_size_scale", &vm_kmem_size_scale);
  585         if (vm_kmem_size_scale > 0 &&
  586             (mem_size / vm_kmem_size_scale) > (vm_kmem_size / PAGE_SIZE))
  587                 vm_kmem_size = (mem_size / vm_kmem_size_scale) * PAGE_SIZE;
  588 
  589 #if defined(VM_KMEM_SIZE_MIN)
  590         vm_kmem_size_min = VM_KMEM_SIZE_MIN;
  591 #endif
  592         TUNABLE_INT_FETCH("vm.kmem_size_min", &vm_kmem_size_min);
  593         if (vm_kmem_size_min > 0 && vm_kmem_size < vm_kmem_size_min) {
  594                 vm_kmem_size = vm_kmem_size_min;
  595         }
  596 
  597 #if defined(VM_KMEM_SIZE_MAX)
  598         vm_kmem_size_max = VM_KMEM_SIZE_MAX;
  599 #endif
  600         TUNABLE_INT_FETCH("vm.kmem_size_max", &vm_kmem_size_max);
  601         if (vm_kmem_size_max > 0 && vm_kmem_size >= vm_kmem_size_max)
  602                 vm_kmem_size = vm_kmem_size_max;
  603 
  604         /* Allow final override from the kernel environment */
  605 #ifndef BURN_BRIDGES
  606         if (TUNABLE_INT_FETCH("kern.vm.kmem.size", &vm_kmem_size) != 0)
  607                 printf("kern.vm.kmem.size is now called vm.kmem_size!\n");
  608 #endif
  609         TUNABLE_INT_FETCH("vm.kmem_size", &vm_kmem_size);
  610 
  611         /*
  612          * Limit kmem virtual size to twice the physical memory.
  613          * This allows for kmem map sparseness, but limits the size
  614          * to something sane. Be careful to not overflow the 32bit
  615          * ints while doing the check.
  616          */
  617         if (((vm_kmem_size / 2) / PAGE_SIZE) > cnt.v_page_count)
  618                 vm_kmem_size = 2 * cnt.v_page_count * PAGE_SIZE;
  619 
  620         /*
  621          * Tune settings based on the kernel map's size at this time.
  622          */
  623         init_param3(vm_kmem_size / PAGE_SIZE);
  624 
  625         kmem_map = kmem_suballoc(kernel_map, &kmembase, &kmemlimit,
  626             vm_kmem_size);
  627         kmem_map->system_map = 1;
  628 
  629 #ifdef DEBUG_MEMGUARD
  630         /*
  631          * Initialize MemGuard if support compiled in.  MemGuard is a
  632          * replacement allocator used for detecting tamper-after-free
  633          * scenarios as they occur.  It is only used for debugging.
  634          */
  635         vm_memguard_divisor = 10;
  636         TUNABLE_INT_FETCH("vm.memguard.divisor", &vm_memguard_divisor);
  637 
  638         /* Pick a conservative value if provided value sucks. */
  639         if ((vm_memguard_divisor <= 0) ||
  640             ((vm_kmem_size / vm_memguard_divisor) == 0))
  641                 vm_memguard_divisor = 10;
  642         memguard_init(kmem_map, vm_kmem_size / vm_memguard_divisor);
  643 #endif
  644 
  645         uma_startup2();
  646 
  647         mt_zone = uma_zcreate("mt_zone", sizeof(struct malloc_type_internal),
  648 #ifdef INVARIANTS
  649             mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
  650 #else
  651             NULL, NULL, NULL, NULL,
  652 #endif
  653             UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
  654         for (i = 0, indx = 0; kmemzones[indx].kz_size != 0; indx++) {
  655                 int size = kmemzones[indx].kz_size;
  656                 char *name = kmemzones[indx].kz_name;
  657 
  658                 kmemzones[indx].kz_zone = uma_zcreate(name, size,
  659 #ifdef INVARIANTS
  660                     mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
  661 #else
  662                     NULL, NULL, NULL, NULL,
  663 #endif
  664                     UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
  665                     
  666                 for (;i <= size; i+= KMEM_ZBASE)
  667                         kmemsize[i >> KMEM_ZSHIFT] = indx;
  668                 
  669         }
  670 }
  671 
  672 void
  673 malloc_init(void *data)
  674 {
  675         struct malloc_type_internal *mtip;
  676         struct malloc_type *mtp;
  677 
  678         KASSERT(cnt.v_page_count != 0, ("malloc_register before vm_init"));
  679 
  680         mtp = data;
  681         mtip = uma_zalloc(mt_zone, M_WAITOK | M_ZERO);
  682         mtp->ks_handle = mtip;
  683 
  684         mtx_lock(&malloc_mtx);
  685         mtp->ks_next = kmemstatistics;
  686         kmemstatistics = mtp;
  687         kmemcount++;
  688         mtx_unlock(&malloc_mtx);
  689 }
  690 
  691 void
  692 malloc_uninit(void *data)
  693 {
  694         struct malloc_type_internal *mtip;
  695         struct malloc_type_stats *mtsp;
  696         struct malloc_type *mtp, *temp;
  697         uma_slab_t slab;
  698         long temp_allocs, temp_bytes;
  699         int i;
  700 
  701         mtp = data;
  702         KASSERT(mtp->ks_handle != NULL, ("malloc_deregister: cookie NULL"));
  703         mtx_lock(&malloc_mtx);
  704         mtip = mtp->ks_handle;
  705         mtp->ks_handle = NULL;
  706         if (mtp != kmemstatistics) {
  707                 for (temp = kmemstatistics; temp != NULL;
  708                     temp = temp->ks_next) {
  709                         if (temp->ks_next == mtp)
  710                                 temp->ks_next = mtp->ks_next;
  711                 }
  712         } else
  713                 kmemstatistics = mtp->ks_next;
  714         kmemcount--;
  715         mtx_unlock(&malloc_mtx);
  716 
  717         /*
  718          * Look for memory leaks.
  719          */
  720         temp_allocs = temp_bytes = 0;
  721         for (i = 0; i < MAXCPU; i++) {
  722                 mtsp = &mtip->mti_stats[i];
  723                 temp_allocs += mtsp->mts_numallocs;
  724                 temp_allocs -= mtsp->mts_numfrees;
  725                 temp_bytes += mtsp->mts_memalloced;
  726                 temp_bytes -= mtsp->mts_memfreed;
  727         }
  728         if (temp_allocs > 0 || temp_bytes > 0) {
  729                 printf("Warning: memory type %s leaked memory on destroy "
  730                     "(%ld allocations, %ld bytes leaked).\n", mtp->ks_shortdesc,
  731                     temp_allocs, temp_bytes);
  732         }
  733 
  734         slab = vtoslab((vm_offset_t) mtip & (~UMA_SLAB_MASK));
  735         uma_zfree_arg(mt_zone, mtip, slab);
  736 }
  737 
  738 struct malloc_type *
  739 malloc_desc2type(const char *desc)
  740 {
  741         struct malloc_type *mtp;
  742 
  743         mtx_assert(&malloc_mtx, MA_OWNED);
  744         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
  745                 if (strcmp(mtp->ks_shortdesc, desc) == 0)
  746                         return (mtp);
  747         }
  748         return (NULL);
  749 }
  750 
  751 static int
  752 sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS)
  753 {
  754         struct malloc_type_stream_header mtsh;
  755         struct malloc_type_internal *mtip;
  756         struct malloc_type_header mth;
  757         struct malloc_type *mtp;
  758         int buflen, count, error, i;
  759         struct sbuf sbuf;
  760         char *buffer;
  761 
  762         mtx_lock(&malloc_mtx);
  763 restart:
  764         mtx_assert(&malloc_mtx, MA_OWNED);
  765         count = kmemcount;
  766         mtx_unlock(&malloc_mtx);
  767         buflen = sizeof(mtsh) + count * (sizeof(mth) +
  768             sizeof(struct malloc_type_stats) * MAXCPU) + 1;
  769         buffer = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
  770         mtx_lock(&malloc_mtx);
  771         if (count < kmemcount) {
  772                 free(buffer, M_TEMP);
  773                 goto restart;
  774         }
  775 
  776         sbuf_new(&sbuf, buffer, buflen, SBUF_FIXEDLEN);
  777 
  778         /*
  779          * Insert stream header.
  780          */
  781         bzero(&mtsh, sizeof(mtsh));
  782         mtsh.mtsh_version = MALLOC_TYPE_STREAM_VERSION;
  783         mtsh.mtsh_maxcpus = MAXCPU;
  784         mtsh.mtsh_count = kmemcount;
  785         if (sbuf_bcat(&sbuf, &mtsh, sizeof(mtsh)) < 0) {
  786                 mtx_unlock(&malloc_mtx);
  787                 error = ENOMEM;
  788                 goto out;
  789         }
  790 
  791         /*
  792          * Insert alternating sequence of type headers and type statistics.
  793          */
  794         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
  795                 mtip = (struct malloc_type_internal *)mtp->ks_handle;
  796 
  797                 /*
  798                  * Insert type header.
  799                  */
  800                 bzero(&mth, sizeof(mth));
  801                 strlcpy(mth.mth_name, mtp->ks_shortdesc, MALLOC_MAX_NAME);
  802                 if (sbuf_bcat(&sbuf, &mth, sizeof(mth)) < 0) {
  803                         mtx_unlock(&malloc_mtx);
  804                         error = ENOMEM;
  805                         goto out;
  806                 }
  807 
  808                 /*
  809                  * Insert type statistics for each CPU.
  810                  */
  811                 for (i = 0; i < MAXCPU; i++) {
  812                         if (sbuf_bcat(&sbuf, &mtip->mti_stats[i],
  813                             sizeof(mtip->mti_stats[i])) < 0) {
  814                                 mtx_unlock(&malloc_mtx);
  815                                 error = ENOMEM;
  816                                 goto out;
  817                         }
  818                 }
  819         }
  820         mtx_unlock(&malloc_mtx);
  821         sbuf_finish(&sbuf);
  822         error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
  823 out:
  824         sbuf_delete(&sbuf);
  825         free(buffer, M_TEMP);
  826         return (error);
  827 }
  828 
  829 SYSCTL_PROC(_kern, OID_AUTO, malloc_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
  830     0, 0, sysctl_kern_malloc_stats, "s,malloc_type_ustats",
  831     "Return malloc types");
  832 
  833 SYSCTL_INT(_kern, OID_AUTO, malloc_count, CTLFLAG_RD, &kmemcount, 0,
  834     "Count of kernel malloc types");
  835 
  836 void
  837 malloc_type_list(malloc_type_list_func_t *func, void *arg)
  838 {
  839         struct malloc_type *mtp, **bufmtp;
  840         int count, i;
  841         size_t buflen;
  842 
  843         mtx_lock(&malloc_mtx);
  844 restart:
  845         mtx_assert(&malloc_mtx, MA_OWNED);
  846         count = kmemcount;
  847         mtx_unlock(&malloc_mtx);
  848 
  849         buflen = sizeof(struct malloc_type *) * count;
  850         bufmtp = malloc(buflen, M_TEMP, M_WAITOK);
  851 
  852         mtx_lock(&malloc_mtx);
  853 
  854         if (count < kmemcount) {
  855                 free(bufmtp, M_TEMP);
  856                 goto restart;
  857         }
  858 
  859         for (mtp = kmemstatistics, i = 0; mtp != NULL; mtp = mtp->ks_next, i++)
  860                 bufmtp[i] = mtp;
  861 
  862         mtx_unlock(&malloc_mtx);
  863 
  864         for (i = 0; i < count; i++)
  865                 (func)(bufmtp[i], arg);
  866 
  867         free(bufmtp, M_TEMP);
  868 }
  869 
  870 #ifdef DDB
  871 DB_SHOW_COMMAND(malloc, db_show_malloc)
  872 {
  873         struct malloc_type_internal *mtip;
  874         struct malloc_type *mtp;
  875         u_int64_t allocs, frees;
  876         u_int64_t alloced, freed;
  877         int i;
  878 
  879         db_printf("%18s %12s  %12s %12s\n", "Type", "InUse", "MemUse",
  880             "Requests");
  881         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
  882                 mtip = (struct malloc_type_internal *)mtp->ks_handle;
  883                 allocs = 0;
  884                 frees = 0;
  885                 alloced = 0;
  886                 freed = 0;
  887                 for (i = 0; i < MAXCPU; i++) {
  888                         allocs += mtip->mti_stats[i].mts_numallocs;
  889                         frees += mtip->mti_stats[i].mts_numfrees;
  890                         alloced += mtip->mti_stats[i].mts_memalloced;
  891                         freed += mtip->mti_stats[i].mts_memfreed;
  892                 }
  893                 db_printf("%18s %12ju %12juK %12ju\n",
  894                     mtp->ks_shortdesc, allocs - frees,
  895                     (alloced - freed + 1023) / 1024, allocs);
  896         }
  897 }
  898 #endif
  899 
  900 #ifdef MALLOC_PROFILE
  901 
  902 static int
  903 sysctl_kern_mprof(SYSCTL_HANDLER_ARGS)
  904 {
  905         int linesize = 64;
  906         struct sbuf sbuf;
  907         uint64_t count;
  908         uint64_t waste;
  909         uint64_t mem;
  910         int bufsize;
  911         int error;
  912         char *buf;
  913         int rsize;
  914         int size;
  915         int i;
  916 
  917         bufsize = linesize * (KMEM_ZSIZE + 1);
  918         bufsize += 128;         /* For the stats line */
  919         bufsize += 128;         /* For the banner line */
  920         waste = 0;
  921         mem = 0;
  922 
  923         buf = malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO);
  924         sbuf_new(&sbuf, buf, bufsize, SBUF_FIXEDLEN);
  925         sbuf_printf(&sbuf, 
  926             "\n  Size                    Requests  Real Size\n");
  927         for (i = 0; i < KMEM_ZSIZE; i++) {
  928                 size = i << KMEM_ZSHIFT;
  929                 rsize = kmemzones[kmemsize[i]].kz_size;
  930                 count = (long long unsigned)krequests[i];
  931 
  932                 sbuf_printf(&sbuf, "%6d%28llu%11d\n", size,
  933                     (unsigned long long)count, rsize);
  934 
  935                 if ((rsize * count) > (size * count))
  936                         waste += (rsize * count) - (size * count);
  937                 mem += (rsize * count);
  938         }
  939         sbuf_printf(&sbuf,
  940             "\nTotal memory used:\t%30llu\nTotal Memory wasted:\t%30llu\n",
  941             (unsigned long long)mem, (unsigned long long)waste);
  942         sbuf_finish(&sbuf);
  943 
  944         error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
  945 
  946         sbuf_delete(&sbuf);
  947         free(buf, M_TEMP);
  948         return (error);
  949 }
  950 
  951 SYSCTL_OID(_kern, OID_AUTO, mprof, CTLTYPE_STRING|CTLFLAG_RD,
  952     NULL, 0, sysctl_kern_mprof, "A", "Malloc Profiling");
  953 #endif /* MALLOC_PROFILE */

Cache object: 291f2e173ad58d93aa18af4e2ab82b27


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