Patch series "Update LZ4 compressor module", v7.
This patchset updates the LZ4 compression module to a version based on
LZ4 v1.7.3 allowing to use the fast compression algorithm aka LZ4 fast
which provides an "acceleration" parameter as a tradeoff between high
compression ratio and high compression speed.
We want to use LZ4 fast in order to support compression in lustre and
(mostly, based on that) investigate data reduction techniques in behalf
of storage systems.
Also, it will be useful for other users of LZ4 compression, as with LZ4
fast it is possible to enable applications to use fast and/or high
compression depending on the usecase. For instance, ZRAM is offering a
LZ4 backend and could benefit from an updated LZ4 in the kernel.
LZ4 homepage: http://www.lz4.org/
LZ4 source repository: https://github.com/lz4/lz4 Source version: 1.7.3
Benchmark (taken from [1], Core i5-4300U @1.9GHz):
----------------|--------------|----------------|----------
Compressor | Compression | Decompression | Ratio
----------------|--------------|----------------|----------
memcpy | 4200 MB/s | 4200 MB/s | 1.000
LZ4 fast 50 | 1080 MB/s | 2650 MB/s | 1.375
LZ4 fast 17 | 680 MB/s | 2220 MB/s | 1.607
LZ4 fast 5 | 475 MB/s | 1920 MB/s | 1.886
LZ4 default | 385 MB/s | 1850 MB/s | 2.101
[1] http://fastcompression.blogspot.de/2015/04/sampling-or-faster-lz4.html
[PATCH 1/5] lib: Update LZ4 compressor module
[PATCH 2/5] lib/decompress_unlz4: Change module to work with new LZ4 module version
[PATCH 3/5] crypto: Change LZ4 modules to work with new LZ4 module version
[PATCH 4/5] fs/pstore: fs/squashfs: Change usage of LZ4 to work with new LZ4 version
[PATCH 5/5] lib/lz4: Remove back-compat wrappers
This patch (of 5):
Update the LZ4 kernel module to LZ4 v1.7.3 by Yann Collet. The kernel
module is inspired by the previous work by Chanho Min. The updated LZ4
module will not break existing code since the patchset contains
appropriate changes.
API changes:
New method LZ4_compress_fast which differs from the variant available in
kernel by the new acceleration parameter, allowing to trade compression
ratio for more compression speed and vice versa.
LZ4_decompress_fast is the respective decompression method, featuring a
very fast decoder (multiple GB/s per core), able to reach RAM speed in
multi-core systems. The decompressor allows to decompress data
compressed with LZ4 fast as well as the LZ4 HC (high compression)
algorithm.
Also the useful functions LZ4_decompress_safe_partial and
LZ4_compress_destsize were added. The latter reverses the logic by
trying to compress as much data as possible from source to dest while
the former aims to decompress partial blocks of data.
A bunch of streaming functions were also added which allow
compressig/decompressing data in multiple steps (so called "streaming
mode").
The methods lz4_compress and lz4_decompress_unknownoutputsize are now
known as LZ4_compress_default respectivley LZ4_decompress_safe. The old
methods will be removed since there's no callers left in the code.
[arnd@arndb.de: fix KERNEL_LZ4 support]
Link: http://lkml.kernel.org/r/20170208211946.2839649-1-arnd@arndb.de
[akpm@linux-foundation.org: simplify]
[akpm@linux-foundation.org: fix the simplification]
[4sschmid@informatik.uni-hamburg.de: fix performance regressions]
Link: http://lkml.kernel.org/r/1486898178-17125-2-git-send-email-4sschmid@informatik.uni-hamburg.de
[4sschmid@informatik.uni-hamburg.de: v8]
Link: http://lkml.kernel.org/r/1487182598-15351-2-git-send-email-4sschmid@informatik.uni-hamburg.de
Link: http://lkml.kernel.org/r/1486321748-19085-2-git-send-email-4sschmid@informatik.uni-hamburg.de
Signed-off-by: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Bongkyu Kim <bongkyu.kim@lge.com>
Cc: Rui Salvaterra <rsalvaterra@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset is for supporting LZ4 compression and the crypto API using
it.
As shown below, the size of data is a little bit bigger but compressing
speed is faster under the enabled unaligned memory access. We can use
lz4 de/compression through crypto API as well. Also, It will be useful
for another potential user of lz4 compression.
lz4 Compression Benchmark:
Compiler: ARM gcc 4.6.4
ARMv7, 1 GHz based board
Kernel: linux 3.4
Uncompressed data Size: 101 MB
Compressed Size compression Speed
LZO 72.1MB 32.1MB/s, 33.0MB/s(UA)
LZ4 75.1MB 30.4MB/s, 35.9MB/s(UA)
LZ4HC 59.8MB 2.4MB/s, 2.5MB/s(UA)
- UA: Unaligned memory Access support
- Latest patch set for LZO applied
This patch:
Add support for LZ4 compression in the Linux Kernel. LZ4 Compression APIs
for kernel are based on LZ4 implementation by Yann Collet and were changed
for kernel coding style.
LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
LZ4 source repository : http://code.google.com/p/lz4/
svn revision : r90
Two APIs are added:
lz4_compress() support basic lz4 compression whereas lz4hc_compress()
support high compression or CPU performance get lower but compression
ratio get higher. Also, we require the pre-allocated working memory with
the defined size and destination buffer must be allocated with the size of
lz4_compressbound.
[akpm@linux-foundation.org: make lz4_compresshcctx() static]
Signed-off-by: Chanho Min <chanho.min@lge.com>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Herbert Xu <herbert@gondor.hengli.com.au>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for extracting LZ4-compressed kernel images, as well as
LZ4-compressed ramdisk images in the kernel boot process.
Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sven Schmidt
Chanho Min
Kyungsik Lee