17 Jul, 2019
1 commit
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Fix a few spelling and grammar errors, and two places where fast/safe in
the documentation did not match the function.Link: http://lkml.kernel.org/r/20190321014452.13297-1-tomlevy93@gmail.com
Signed-off-by: Tom Levy
Reviewed-by: Andrew Morton
Cc: Jiri Kosina
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Feb, 2017
2 commits
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Remove the functions introduced as wrappers for providing backwards
compatibility to the prior LZ4 version. They're not needed anymore
since there's no callers left.Link: http://lkml.kernel.org/r/1486321748-19085-6-git-send-email-4sschmid@informatik.uni-hamburg.de
Signed-off-by: Sven Schmidt
Cc: Bongkyu Kim
Cc: Rui Salvaterra
Cc: Sergey Senozhatsky
Cc: Greg Kroah-Hartman
Cc: Herbert Xu
Cc: David S. Miller
Cc: Anton Vorontsov
Cc: Colin Cross
Cc: Kees Cook
Cc: Tony Luck
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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: 1.7.3Benchmark (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 wrappersThis 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
Signed-off-by: Arnd Bergmann
Cc: Bongkyu Kim
Cc: Rui Salvaterra
Cc: Sergey Senozhatsky
Cc: Greg Kroah-Hartman
Cc: Herbert Xu
Cc: David S. Miller
Cc: Anton Vorontsov
Cc: Colin Cross
Cc: Kees Cook
Cc: Tony Luck
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Jan, 2016
1 commit
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The current lz4 compress buffer is 16kb on 32-bits, 32kb on 64-bits
system. But, lz4 needs only 16kb on both. On 64-bits, this causes
wasted cpu cycles for additional memset during every compression.In case of lz4hc, the current buffer size is (256kb + 8) on 32-bits,
(512kb + 16) on 64-bits. But, lz4hc needs only (256kb + 2 * pointer) on
both.This patch fixes these wrong compress buffer sizes for 64-bits.
Signed-off-by: Bongkyu Kim
Cc: Chanho Min
Cc: Yann Collet
Cc: Kyungsik Lee
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Sep, 2013
1 commit
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LZ4 compression and decompression functions require different in
signedness input/output parameters: unsigned char for compression and
signed char for decompression.Change decompression API to require "(const) unsigned char *".
Signed-off-by: Sergey Senozhatsky
Cc: Kyungsik Lee
Cc: Geert Uytterhoeven
Cc: Yann Collet
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Jul, 2013
2 commits
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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 appliedThis 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 : r90Two 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
Cc: "Darrick J. Wong"
Cc: Bob Pearson
Cc: Richard Weinberger
Cc: Herbert Xu
Cc: Yann Collet
Cc: Kyungsik Lee
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add support for LZ4 decompression in the Linux Kernel. LZ4 Decompression
APIs for kernel are based on LZ4 implementation by Yann Collet.Benchmark Results(PATCH v3)
Compiler: Linaro ARM gcc 4.6.21. ARMv7, 1.5GHz based board
Kernel: linux 3.4
Uncompressed Kernel Size: 14MB
Compressed Size Decompression Speed
LZO 6.7MB 20.1MB/s, 25.2MB/s(UA)
LZ4 7.3MB 29.1MB/s, 45.6MB/s(UA)2. ARMv7, 1.7GHz based board
Kernel: linux 3.7
Uncompressed Kernel Size: 14MB
Compressed Size Decompression Speed
LZO 6.0MB 34.1MB/s, 52.2MB/s(UA)
LZ4 6.5MB 86.7MB/s
- UA: Unaligned memory Access support
- Latest patch set for LZO appliedThis patch set is for adding support for LZ4-compressed Kernel. LZ4 is a
very fast lossless compression algorithm and it also features an extremely
fast decoder [1].But we have five of decompressors already and one question which does
arise, however, is that of where do we stop adding new ones? This issue
had been discussed and came to the conclusion [2].Russell King said that we should have:
- one decompressor which is the fastest
- one decompressor for the highest compression ratio
- one popular decompressor (eg conventional gzip)If we have a replacement one for one of these, then it should do exactly
that: replace it.The benchmark shows that an 8% increase in image size vs a 66% increase
in decompression speed compared to LZO(which has been known as the
fastest decompressor in the Kernel). Therefore the "fast but may not be
small" compression title has clearly been taken by LZ4 [3].[1] http://code.google.com/p/lz4/
[2] http://thread.gmane.org/gmane.linux.kbuild.devel/9157
[3] http://thread.gmane.org/gmane.linux.kbuild.devel/9347LZ4 homepage: http://fastcompression.blogspot.com/p/lz4.html
LZ4 source repository: http://code.google.com/p/lz4/Signed-off-by: Kyungsik Lee
Signed-off-by: Yann Collet
Cc: "H. Peter Anvin"
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Russell King
Cc: Borislav Petkov
Cc: Florian Fainelli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
