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linux/lib/zstd/zstd_decompress_module.c
Sergey Senozhatsky 4fc4187984 lib: zstd: export API needed for dictionary support
Patch series "zram: introduce custom comp backends API", v7.

This series introduces support for run-time compression algorithms tuning,
so users, for instance, can adjust compression/acceleration levels and
provide pre-trained compression/decompression dictionaries which certain
algorithms support.

At this point we stop supporting (old/deprecated) comp API.  We may add
new acomp API support in the future, but before that zram needs to undergo
some major rework (we are not ready for async compression).

Some benchmarks for reference (look at column #2)

*** init zstd
/sys/block/zram0/mm_stat
1750659072 504622188 514355200        0 514355200        1        0    34204    34204

*** init zstd dict=/home/ss/zstd-dict-amd64
/sys/block/zram0/mm_stat
1750650880 465908890 475398144        0 475398144        1        0    34185    34185

*** init zstd level=8 dict=/home/ss/zstd-dict-amd64
/sys/block/zram0/mm_stat
1750654976 430803319 439873536        0 439873536        1        0    34185    34185

*** init lz4
/sys/block/zram0/mm_stat
1750646784 664266564 677060608        0 677060608        1        0    34288    34288

*** init lz4 dict=/home/ss/lz4-dict-amd64
/sys/block/zram0/mm_stat
1750650880 619990300 632102912        0 632102912        1        0    34278    34278

*** init lz4hc
/sys/block/zram0/mm_stat
1750630400 609023822 621232128        0 621232128        1        0    34288    34288

*** init lz4hc dict=/home/ss/lz4-dict-amd64
/sys/block/zram0/mm_stat
1750659072 505133172 515231744        0 515231744        1        0    34278    34278


Recompress
init zram zstd (prio=0), zstd level=5 (prio 1), zstd with dict (prio 2)

*** zstd
/sys/block/zram0/mm_stat
1750982656 504630584 514269184        0 514269184        1        0    34204    34204

*** idle recompress priority=1 (zstd level=5)
/sys/block/zram0/mm_stat
1750982656 488645601 525438976        0 514269184        1        0    34204    34204

*** idle recompress priority=2 (zstd dict)
/sys/block/zram0/mm_stat
1750982656 460869640 517914624        0 514269184        1        0    34185    34204


This patch (of 24):

We need to export a number of API functions that enable advanced zstd
usage - C/D dictionaries, dictionaries sharing between contexts, etc.

Link: https://lkml.kernel.org/r/20240902105656.1383858-1-senozhatsky@chromium.org
Link: https://lkml.kernel.org/r/20240902105656.1383858-2-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:06 -07:00

142 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
/*
* Copyright (c) Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/zstd.h>
#include "common/zstd_deps.h"
/* Common symbols. zstd_compress must depend on zstd_decompress. */
unsigned int zstd_is_error(size_t code)
{
return ZSTD_isError(code);
}
EXPORT_SYMBOL(zstd_is_error);
zstd_error_code zstd_get_error_code(size_t code)
{
return ZSTD_getErrorCode(code);
}
EXPORT_SYMBOL(zstd_get_error_code);
const char *zstd_get_error_name(size_t code)
{
return ZSTD_getErrorName(code);
}
EXPORT_SYMBOL(zstd_get_error_name);
/* Decompression symbols. */
size_t zstd_dctx_workspace_bound(void)
{
return ZSTD_estimateDCtxSize();
}
EXPORT_SYMBOL(zstd_dctx_workspace_bound);
zstd_dctx *zstd_create_dctx_advanced(zstd_custom_mem custom_mem)
{
return ZSTD_createDCtx_advanced(custom_mem);
}
EXPORT_SYMBOL(zstd_create_dctx_advanced);
size_t zstd_free_dctx(zstd_dctx *dctx)
{
return ZSTD_freeDCtx(dctx);
}
EXPORT_SYMBOL(zstd_free_dctx);
zstd_ddict *zstd_create_ddict_byreference(const void *dict, size_t dict_size,
zstd_custom_mem custom_mem)
{
return ZSTD_createDDict_advanced(dict, dict_size, ZSTD_dlm_byRef,
ZSTD_dct_auto, custom_mem);
}
EXPORT_SYMBOL(zstd_create_ddict_byreference);
size_t zstd_free_ddict(zstd_ddict *ddict)
{
return ZSTD_freeDDict(ddict);
}
EXPORT_SYMBOL(zstd_free_ddict);
zstd_dctx *zstd_init_dctx(void *workspace, size_t workspace_size)
{
if (workspace == NULL)
return NULL;
return ZSTD_initStaticDCtx(workspace, workspace_size);
}
EXPORT_SYMBOL(zstd_init_dctx);
size_t zstd_decompress_dctx(zstd_dctx *dctx, void *dst, size_t dst_capacity,
const void *src, size_t src_size)
{
return ZSTD_decompressDCtx(dctx, dst, dst_capacity, src, src_size);
}
EXPORT_SYMBOL(zstd_decompress_dctx);
size_t zstd_decompress_using_ddict(zstd_dctx *dctx,
void *dst, size_t dst_capacity, const void* src, size_t src_size,
const zstd_ddict* ddict)
{
return ZSTD_decompress_usingDDict(dctx, dst, dst_capacity, src,
src_size, ddict);
}
EXPORT_SYMBOL(zstd_decompress_using_ddict);
size_t zstd_dstream_workspace_bound(size_t max_window_size)
{
return ZSTD_estimateDStreamSize(max_window_size);
}
EXPORT_SYMBOL(zstd_dstream_workspace_bound);
zstd_dstream *zstd_init_dstream(size_t max_window_size, void *workspace,
size_t workspace_size)
{
if (workspace == NULL)
return NULL;
(void)max_window_size;
return ZSTD_initStaticDStream(workspace, workspace_size);
}
EXPORT_SYMBOL(zstd_init_dstream);
size_t zstd_reset_dstream(zstd_dstream *dstream)
{
return ZSTD_resetDStream(dstream);
}
EXPORT_SYMBOL(zstd_reset_dstream);
size_t zstd_decompress_stream(zstd_dstream *dstream, zstd_out_buffer *output,
zstd_in_buffer *input)
{
return ZSTD_decompressStream(dstream, output, input);
}
EXPORT_SYMBOL(zstd_decompress_stream);
size_t zstd_find_frame_compressed_size(const void *src, size_t src_size)
{
return ZSTD_findFrameCompressedSize(src, src_size);
}
EXPORT_SYMBOL(zstd_find_frame_compressed_size);
size_t zstd_get_frame_header(zstd_frame_header *header, const void *src,
size_t src_size)
{
return ZSTD_getFrameHeader(header, src, src_size);
}
EXPORT_SYMBOL(zstd_get_frame_header);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("Zstd Decompressor");