root/fs/xfs/linux-2.6/kmem.c

DEFINITIONS

1. kmem_alloc
2. kmem_zalloc
3. kmem_zalloc_greedy
4. kmem_free
5. kmem_realloc
6. kmem_zone_alloc
7. kmem_zone_zalloc

/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include <linux/swap.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include "time.h"
#include "kmem.h"

#define MAX_VMALLOCS    6
#define MAX_SLAB_SIZE   0x20000

void *
kmem_alloc(size_t size, unsigned int __nocast flags)
{
        int     retries = 0;
        gfp_t   lflags = kmem_flags_convert(flags);
        void    *ptr;

#ifdef DEBUG
        if (unlikely(!(flags & KM_LARGE) && (size > PAGE_SIZE))) {
                printk(KERN_WARNING "Large %s attempt, size=%ld\n",
                        __func__, (long)size);
                dump_stack();
        }
#endif

        do {
                if (size < MAX_SLAB_SIZE || retries > MAX_VMALLOCS)
                        ptr = kmalloc(size, lflags);
                else
                        ptr = __vmalloc(size, lflags, PAGE_KERNEL);
                if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
                        return ptr;
                if (!(++retries % 100))
                        printk(KERN_ERR "XFS: possible memory allocation "
                                        "deadlock in %s (mode:0x%x)\n",
                                        __func__, lflags);
                congestion_wait(WRITE, HZ/50);
        } while (1);
}

void *
kmem_zalloc(size_t size, unsigned int __nocast flags)
{
        void    *ptr;

        ptr = kmem_alloc(size, flags);
        if (ptr)
                memset((char *)ptr, 0, (int)size);
        return ptr;
}

void *
kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize,
                   unsigned int __nocast flags)
{
        void            *ptr;
        size_t          kmsize = maxsize;
        unsigned int    kmflags = (flags & ~KM_SLEEP) | KM_NOSLEEP;

        while (!(ptr = kmem_zalloc(kmsize, kmflags))) {
                if ((kmsize <= minsize) && (flags & KM_NOSLEEP))
                        break;
                if ((kmsize >>= 1) <= minsize) {
                        kmsize = minsize;
                        kmflags = flags;
                }
        }
        if (ptr)
                *size = kmsize;
        return ptr;
}

void
kmem_free(const void *ptr)
{
        if (!is_vmalloc_addr(ptr)) {
                kfree(ptr);
        } else {
                vfree(ptr);
        }
}

void *
kmem_realloc(const void *ptr, size_t newsize, size_t oldsize,
             unsigned int __nocast flags)
{
        void    *new;

        new = kmem_alloc(newsize, flags);
        if (ptr) {
                if (new)
                        memcpy(new, ptr,
                                ((oldsize < newsize) ? oldsize : newsize));
                kmem_free(ptr);
        }
        return new;
}

void *
kmem_zone_alloc(kmem_zone_t *zone, unsigned int __nocast flags)
{
        int     retries = 0;
        gfp_t   lflags = kmem_flags_convert(flags);
        void    *ptr;

        do {
                ptr = kmem_cache_alloc(zone, lflags);
                if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
                        return ptr;
                if (!(++retries % 100))
                        printk(KERN_ERR "XFS: possible memory allocation "
                                        "deadlock in %s (mode:0x%x)\n",
                                        __func__, lflags);
                congestion_wait(WRITE, HZ/50);
        } while (1);
}

void *
kmem_zone_zalloc(kmem_zone_t *zone, unsigned int __nocast flags)
{
        void    *ptr;

        ptr = kmem_zone_alloc(zone, flags);
        if (ptr)
                memset((char *)ptr, 0, kmem_cache_size(zone));
        return ptr;
}