fs/xfs/linux-2.6/kmem.c

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include <linux/mm.h>
  19 #include <linux/vmalloc.h>
  20 #include <linux/highmem.h>
  21 #include <linux/swap.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/backing-dev.h>
  24 #include "time.h"
  25 #include "kmem.h"
  26
  27 #define MAX_VMALLOCS    6
  28 #define MAX_SLAB_SIZE   0x20000
  29
  30 void *
  31 kmem_alloc(size_t size, unsigned int __nocast flags)
  32 {
  33         int     retries = 0;
  34         gfp_t   lflags = kmem_flags_convert(flags);
  35         void    *ptr;
  36
  37 #ifdef DEBUG
  38         if (unlikely(!(flags & KM_LARGE) && (size > PAGE_SIZE))) {
  39                 printk(KERN_WARNING "Large %s attempt, size=%ld\n",
  40                         __func__, (long)size);
  41                 dump_stack();
  42         }
  43 #endif
  44
  45         do {
  46                 if (size < MAX_SLAB_SIZE || retries > MAX_VMALLOCS)
  47                         ptr = kmalloc(size, lflags);
  48                 else
  49                         ptr = __vmalloc(size, lflags, PAGE_KERNEL);
  50                 if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  51                         return ptr;
  52                 if (!(++retries % 100))
  53                         printk(KERN_ERR "XFS: possible memory allocation "
  54                                         "deadlock in %s (mode:0x%x)\n",
  55                                         __func__, lflags);
  56                 congestion_wait(WRITE, HZ/50);
  57         } while (1);
  58 }
  59
  60 void *
  61 kmem_zalloc(size_t size, unsigned int __nocast flags)
  62 {
  63         void    *ptr;
  64
  65         ptr = kmem_alloc(size, flags);
  66         if (ptr)
  67                 memset((char *)ptr, 0, (int)size);
  68         return ptr;
  69 }
  70
  71 void *
  72 kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize,
  73                    unsigned int __nocast flags)
  74 {
  75         void            *ptr;
  76         size_t          kmsize = maxsize;
  77         unsigned int    kmflags = (flags & ~KM_SLEEP) | KM_NOSLEEP;
  78
  79         while (!(ptr = kmem_zalloc(kmsize, kmflags))) {
  80                 if ((kmsize <= minsize) && (flags & KM_NOSLEEP))
  81                         break;
  82                 if ((kmsize >>= 1) <= minsize) {
  83                         kmsize = minsize;
  84                         kmflags = flags;
  85                 }
  86         }
  87         if (ptr)
  88                 *size = kmsize;
  89         return ptr;
  90 }
  91
  92 void
  93 kmem_free(void *ptr, size_t size)
  94 {
  95         if (!is_vmalloc_addr(ptr)) {
  96                 kfree(ptr);
  97         } else {
  98                 vfree(ptr);
  99         }
 100 }
 101
 102 void *
 103 kmem_realloc(void *ptr, size_t newsize, size_t oldsize,
 104              unsigned int __nocast flags)
 105 {
 106         void    *new;
 107
 108         new = kmem_alloc(newsize, flags);
 109         if (ptr) {
 110                 if (new)
 111                         memcpy(new, ptr,
 112                                 ((oldsize < newsize) ? oldsize : newsize));
 113                 kmem_free(ptr, oldsize);
 114         }
 115         return new;
 116 }
 117
 118 void *
 119 kmem_zone_alloc(kmem_zone_t *zone, unsigned int __nocast flags)
 120 {
 121         int     retries = 0;
 122         gfp_t   lflags = kmem_flags_convert(flags);
 123         void    *ptr;
 124
 125         do {
 126                 ptr = kmem_cache_alloc(zone, lflags);
 127                 if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
 128                         return ptr;
 129                 if (!(++retries % 100))
 130                         printk(KERN_ERR "XFS: possible memory allocation "
 131                                         "deadlock in %s (mode:0x%x)\n",
 132                                         __func__, lflags);
 133                 congestion_wait(WRITE, HZ/50);
 134         } while (1);
 135 }
 136
 137 void *
 138 kmem_zone_zalloc(kmem_zone_t *zone, unsigned int __nocast flags)
 139 {
 140         void    *ptr;
 141
 142         ptr = kmem_zone_alloc(zone, flags);
 143         if (ptr)
 144                 memset((char *)ptr, 0, kmem_cache_size(zone));
 145         return ptr;
 146 }