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2019-07-17include/linux/lz4.h: fix spelling and copy-paste errors in documentationTom Levy1-9/+9
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 <tomlevy93@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Kosina <trivial@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-25lib/lz4: remove back-compat wrappersSven Schmidt1-69/+0
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 <4sschmid@informatik.uni-hamburg.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>
2017-02-25lib: update LZ4 compressor moduleSven Schmidt1-66/+696
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>
2016-01-21lz4: fix wrong compress buffer size for 64-bitsBongkyu Kim1-2/+2
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 <bongkyu.kim@lge.com> Cc: Chanho Min <chanho.min@lge.com> 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>
2013-09-12lz4: fix compression/decompression signedness mismatchSergey Senozhatsky1-4/+4
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 <sergey.senozhatsky@gmail.com> Cc: Kyungsik Lee <kyungsik.lee@lge.com> Cc: Geert Uytterhoeven <geert@linux-m68k.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>
2013-07-09lib: add lz4 compressor moduleChanho Min1-0/+36
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>
2013-07-09decompressor: add LZ4 decompressor moduleKyungsik Lee1-0/+51
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 4.6.2 1. 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 applied This 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/9347 LZ4 homepage: http://fastcompression.blogspot.com/p/lz4.html LZ4 source repository: http://code.google.com/p/lz4/ Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com> Signed-off-by: Yann Collet <yann.collet.73@gmail.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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>