Eric Lee / smarc-fsl-linux-kernel

12 Jan, 2010

1 commit

  • 7dd65feb6   lib: add support for LZO-compressed kernels ... Browse Code »

    This patch series adds generic support for creating and extracting
    LZO-compressed kernel images, as well as support for using such images on
    the x86 and ARM architectures, and support for creating and using
    LZO-compressed initrd and initramfs images.

    Russell King said:

    : Testing on a Cortex A9 model:
    : - lzo decompressor is 65% of the time gzip takes to decompress a kernel
    : - lzo kernel is 9% larger than a gzip kernel
    :
    : which I'm happy to say confirms your figures when comparing the two.
    :
    : However, when comparing your new gzip code to the old gzip code:
    : - new is 99% of the size of the old code
    : - new takes 42% of the time to decompress than the old code
    :
    : What this means is that for a proper comparison, the results get even better:
    : - lzo is 7.5% larger than the old gzip'd kernel image
    : - lzo takes 28% of the time that the old gzip code took
    :
    : So the expense seems definitely worth the effort. The only reason I
    : can think of ever using gzip would be if you needed the additional
    : compression (eg, because you have limited flash to store the image.)
    :
    : I would argue that the default for ARM should therefore be LZO.

    This patch:

    The lzo compressor is worse than gzip at compression, but faster at
    extraction. Here are some figures for an ARM board I'm working on:

    Uncompressed size: 3.24Mo
    gzip 1.61Mo 0.72s
    lzo 1.75Mo 0.48s

    So for a compression ratio that is still relatively close to gzip, it's
    much faster to extract, at least in that case.

    This part contains:
    - Makefile routine to support lzo compression
    - Fixes to the existing lzo compressor so that it can be used in
    compressed kernels
    - wrapper around the existing lzo1x_decompress, as it only extracts one
    block at a time, while we need to extract a whole file here
    - config dialog for kernel compression

    [akpm@linux-foundation.org: coding-style fixes]
    [akpm@linux-foundation.org: cleanup]
    Signed-off-by: Albin Tonnerre
    Tested-by: Wu Zhangjin
    Acked-by: "H. Peter Anvin"
    Cc: Ingo Molnar
    Cc: Thomas Gleixner
    Tested-by: Russell King
    Acked-by: Russell King
    Cc: Ralf Baechle
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Albin Tonnerre
     

26 Jul, 2008

1 commit

11 Apr, 2008

1 commit

  • a1e58bbdc   lzo: fix typo in decompressor ... Browse Code »

    Shift of a LE value seems strange, probably meant to shift the cpu-order
    variable as in the prvious section of the switch statement.

    Signed-off-by: Harvey Harrison
    Acked-by: Richard Purdie
    Signed-off-by: Linus Torvalds

    Harvey Harrison
     

01 Aug, 2007

1 commit

  • c21b37f64   lzo: add some missing casts ... Browse Code »

    Add some casts to the LZO compression algorithm after they were removed
    during cleanup and shouldn't have been.

    Signed-off-by: Richard Purdie
    Cc: Edward Shishkin
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Richard Purdie
     

11 Jul, 2007

1 commit

  • 64c70b1cf   Add LZO1X algorithm to the kernel ... Browse Code »

    This is a hybrid version of the patch to add the LZO1X compression
    algorithm to the kernel. Nitin and myself have merged the best parts of
    the various patches to form this version which we're both happy with (and
    are jointly signing off).

    The performance of this version is equivalent to the original minilzo code
    it was based on. Bytecode comparisons have also been made on ARM, i386 and
    x86_64 with favourable results.

    There are several users of LZO lined up including jffs2, crypto and reiser4
    since its much faster than zlib.

    Signed-off-by: Nitin Gupta
    Signed-off-by: Richard Purdie
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Richard Purdie