kmem.c

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/*
 * 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/highmem.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include "time.h"
#include "kmem.h"
#include "xfs_message.h"

/*
 * Greedy allocation.  May fail and may return vmalloced memory.
 *
 * Must be freed using kmem_free_large.
 */
void *
kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize)
{
    void        *ptr;
    size_t      kmsize = maxsize;

    while (!(ptr = kmem_zalloc_large(kmsize))) {
        if ((kmsize >>= 1) <= minsize)
            kmsize = minsize;
    }
    if (ptr)
        *size = kmsize;
    return ptr;
}

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

    do {
        ptr = kmalloc(size, lflags);
        if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
            return ptr;
        if (!(++retries % 100))
            xfs_err(NULL,
        "possible memory allocation deadlock in %s (mode:0x%x)",
                    __func__, lflags);
        congestion_wait(BLK_RW_ASYNC, HZ/50);
    } while (1);
}

void *
kmem_zalloc(size_t size, xfs_km_flags_t flags)
{
    void    *ptr;

    ptr = kmem_alloc(size, flags);
    if (ptr)
        memset((char *)ptr, 0, (int)size);
    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,
         xfs_km_flags_t 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, xfs_km_flags_t 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))
            xfs_err(NULL,
        "possible memory allocation deadlock in %s (mode:0x%x)",
                    __func__, lflags);
        congestion_wait(BLK_RW_ASYNC, HZ/50);
    } while (1);
}

void *
kmem_zone_zalloc(kmem_zone_t *zone, xfs_km_flags_t flags)
{
    void    *ptr;

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