Eric Lee / smarc-ti-linux-kernel

12 Sep, 2013

1 commit

  • b34081f1c   lz4: fix compression/decompression signedness mismatch ... Browse Code »

    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

    Sergey Senozhatsky
     

24 Aug, 2013

1 commit

  • ee8a99bdb   lib/lz4: correct the LZ4 license ... Browse Code »

    The LZ4 code is listed as using the "BSD 2-Clause License".

    Signed-off-by: Richard Laager
    Acked-by: Kyungsik Lee
    Cc: Chanho Min
    Cc: Richard Yao
    Signed-off-by: Andrew Morton
    [ 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

    Richard Laager
     

10 Jul, 2013

3 commits

  • c72ac7a1a   lib: add lz4 compressor module ... Browse Code »

    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
    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

    Chanho Min
     
  • e76e1fdfa   lib: add support for LZ4-compressed kernel ... Browse Code »

    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
    Cc: "H. Peter Anvin"
    Cc: Ingo Molnar
    Cc: Thomas Gleixner
    Cc: Russell King
    Cc: Borislav Petkov
    Cc: Florian Fainelli
    Cc: Yann Collet
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Kyungsik Lee
     
  • cffb78b0e   decompressor: add LZ4 decompressor module ... Browse Code »

    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
    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

    Kyungsik Lee