• Chanho Min's avatar
    lib: add lz4 compressor module · c72ac7a1
    Chanho Min authored
    This patchset is for supporting LZ4 compression and the crypto API using
    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
    [akpm@linux-foundation.org: make lz4_compresshcctx() static]
    Signed-off-by: default avatarChanho 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: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
lz4defs.h 3.74 KB