linux_dsm_epyc7002/drivers/block/zram/zcomp_lz4.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/lz4.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include "zcomp_lz4.h"
static void *zcomp_lz4_create(gfp_t flags)
{
void *ret;
ret = kmalloc(LZ4_MEM_COMPRESS, flags);
if (!ret)
ret = __vmalloc(LZ4_MEM_COMPRESS,
flags | __GFP_HIGHMEM,
PAGE_KERNEL);
return ret;
}
static void zcomp_lz4_destroy(void *private)
{
kvfree(private);
}
static int zcomp_lz4_compress(const unsigned char *src, unsigned char *dst,
size_t *dst_len, void *private)
{
/* return : Success if return 0 */
return lz4_compress(src, PAGE_SIZE, dst, dst_len, private);
}
static int zcomp_lz4_decompress(const unsigned char *src, size_t src_len,
unsigned char *dst)
{
size_t dst_len = PAGE_SIZE;
/* return : Success if return 0 */
return lz4_decompress_unknownoutputsize(src, src_len, dst, &dst_len);
}
struct zcomp_backend zcomp_lz4 = {
.compress = zcomp_lz4_compress,
.decompress = zcomp_lz4_decompress,
.create = zcomp_lz4_create,
.destroy = zcomp_lz4_destroy,
.name = "lz4",
};