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2020-08-14lz4: fix kernel decompression speedNick Terrell
This patch replaces all memcpy() calls with LZ4_memcpy() which calls __builtin_memcpy() so the compiler can inline it. LZ4 relies heavily on memcpy() with a constant size being inlined. In x86 and i386 pre-boot environments memcpy() cannot be inlined because memcpy() doesn't get defined as __builtin_memcpy(). An equivalent patch has been applied upstream so that the next import won't lose this change [1]. I've measured the kernel decompression speed using QEMU before and after this patch for the x86_64 and i386 architectures. The speed-up is about 10x as shown below. Code Arch Kernel Size Time Speed v5.8 x86_64 11504832 B 148 ms 79 MB/s patch x86_64 11503872 B 13 ms 885 MB/s v5.8 i386 9621216 B 91 ms 106 MB/s patch i386 9620224 B 10 ms 962 MB/s I also measured the time to decompress the initramfs on x86_64, i386, and arm. All three show the same decompression speed before and after, as expected. [1] https://github.com/lz4/lz4/pull/890 Signed-off-by: Nick Terrell <terrelln@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Yann Collet <yann.collet.73@gmail.com> Cc: Gao Xiang <gaoxiang25@huawei.com> Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Link: http://lkml.kernel.org/r/20200803194022.2966806-1-nickrterrell@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-20lz4: do not export static symbolLinus Torvalds
Kbuild now complains (rightly) about it. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24lib/lz4: remove back-compat wrappersSven Schmidt
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>
2017-02-24lib: update LZ4 compressor moduleSven Schmidt
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>
2013-08-23lib/lz4: correct the LZ4 licenseRichard Laager
The LZ4 code is listed as using the "BSD 2-Clause License". Signed-off-by: Richard Laager <rlaager@wiktel.com> Acked-by: Kyungsik Lee <kyungsik.lee@lge.com> Cc: Chanho Min <chanho.min@lge.com> Cc: Richard Yao <ryao@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ The 2-clause BSD can be just converted into GPL, but that's rude and pointless, so don't do it - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09lib: add lz4 compressor moduleChanho Min
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>