This patchset is for supporting LZ4 compressed kernel and initial ramdisk on the x86 and ARM architectures. According to http://code.google.com/p/lz4/, LZ4 is a very fast lossless compression algorithm and also features an extremely fast decoder. Kernel Decompression APIs are based on implementation by Yann Collet (http://code.google.com/p/lz4/source/checkout). De/compression Tools are also provided from the site above. The initial test result on ARM(v7) based board shows that the size of kernel with LZ4 compressed is 8% bigger than LZO compressed but the decompressing speed is faster(especially under the enabled unaligned memory access). Test: 3.4 based kernel built with many modules Uncompressed kernel size: 13MB lzo: 6.3MB, 301ms lz4: 6.8MB, 251ms(167ms, with enabled unaligned memory access) It seems that it’s worth trying LZ4 compressed kernel image or ramdisk for making the kernel boot more faster. Thanks, Kyungsik Kyungsik Lee (4): decompressors: add lz4 decompressor module lib: add support for LZ4-compressed kernels arm: add support for LZ4-compressed kernels x86: add support for LZ4-compressed kernels arch/arm/Kconfig | 1 + arch/arm/boot/compressed/.gitignore | 1 + arch/arm/boot/compressed/Makefile | 3 +- arch/arm/boot/compressed/decompress.c | 4 + arch/arm/boot/compressed/piggy.lz4.S | 6 + arch/x86/Kconfig | 1 + arch/x86/boot/compressed/Makefile | 5 +- arch/x86/boot/compressed/misc.c | 4 + include/linux/decompress/unlz4.h | 10 ++ include/linux/lz4.h | 62 +++++++++++ init/Kconfig | 13 ++- lib/Kconfig | 7 ++ lib/Makefile | 2 + lib/decompress.c | 5 + lib/decompress_unlz4.c | 199 ++++++++++++++++++++++++++++++++++ lib/lz4/Makefile | 1 + lib/lz4/lz4_decompress.c | 199 ++++++++++++++++++++++++++++++++++ lib/lz4/lz4defs.h | 129 ++++++++++++++++++++++ scripts/Makefile.lib | 5 + usr/Kconfig | 9 ++ 20 files changed, 663 insertions(+), 3 deletions(-) create mode 100644 arch/arm/boot/compressed/piggy.lz4.S create mode 100644 include/linux/decompress/unlz4.h create mode 100644 include/linux/lz4.h create mode 100644 lib/decompress_unlz4.c create mode 100644 lib/lz4/Makefile create mode 100644 lib/lz4/lz4_decompress.c create mode 100644 lib/lz4/lz4defs.h -- 1.8.0.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
