linux/drivers/block/zram/zcomp_lzo.c
Sergey Senozhatsky e02d238c98 zram/zcomp: do not zero out zcomp private pages
Do not __GFP_ZERO allocated zcomp ->private pages.  We keep allocated
streams around and use them for read/write requests, so we supply a
zeroed out ->private to compression algorithm as a scratch buffer only
once -- the first time we use that stream.  For the rest of IO requests
served by this stream ->private usually contains some temporarily data
from the previous requests.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 11:40:52 -08:00

57 lines
1.3 KiB
C

/*
* Copyright (C) 2014 Sergey Senozhatsky.
*
* 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; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/lzo.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include "zcomp_lzo.h"
static void *lzo_create(gfp_t flags)
{
void *ret;
ret = kmalloc(LZO1X_MEM_COMPRESS, flags);
if (!ret)
ret = __vmalloc(LZO1X_MEM_COMPRESS,
flags | __GFP_HIGHMEM,
PAGE_KERNEL);
return ret;
}
static void lzo_destroy(void *private)
{
kvfree(private);
}
static int lzo_compress(const unsigned char *src, unsigned char *dst,
size_t *dst_len, void *private)
{
int ret = lzo1x_1_compress(src, PAGE_SIZE, dst, dst_len, private);
return ret == LZO_E_OK ? 0 : ret;
}
static int lzo_decompress(const unsigned char *src, size_t src_len,
unsigned char *dst)
{
size_t dst_len = PAGE_SIZE;
int ret = lzo1x_decompress_safe(src, src_len, dst, &dst_len);
return ret == LZO_E_OK ? 0 : ret;
}
struct zcomp_backend zcomp_lzo = {
.compress = lzo_compress,
.decompress = lzo_decompress,
.create = lzo_create,
.destroy = lzo_destroy,
.name = "lzo",
};