On 5/28/07, Nitin Gupta <[EMAIL PROTECTED]> wrote:
Hi,This is kernel port of LZO1X-1 compressor and LZO1X decompressor (safe version only). * Changes since 'take 5' (Full Changelog after this): - Added compressor and decomrpesssor as separate and hidden config options (default: n) - Cleanups: removed LZO_CHECK_MPOS_NON_DET macro - removed PTR* macros. * Benchmarks: (system: P4 3GHz, 1G RAM) (Using tester program from Daniel) Following compares this kernel port ('take 6') vs original miniLZO code: 'TinyLZO' refers to this kernel port. 10000 run averages: 'Tiny LZO': Combined: 61.2223 usec Compression: 41.8412 usec Decompression: 19.3811 usec 'miniLZO': Combined: 66.0444 usec Compression: 46.6323 usec Decompression: 19.4121 usec Result: Overall: TinyLZO is 7.3% faster Compressor: TinyLZO is 10.2% faster Decompressor: TinyLZO is 0.15% faster TODO: test 'take 6' port on archs other than x86(_32) * Changelog vs. original LZO: 1) Used standard/kernel defined data types: (this eliminated _huge_ #ifdef chunks) lzo_bytep -> unsigned char * lzo_uint -> size_t lzo_xint -> size_t lzo_uint32p -> u32 * lzo_uintptr_t -> unsigned long 2) Removed everything #ifdef'ed under COPY_DICT (this is not set for LZO1X, so removed corres. parts). 3) Removed code #ifdef'ed for LZO1Y, LZO1Z, other variants. 4) Reformatted the code to match general kernel style. 5) The only code change: (as suggested by Andrey) -#if defined(__LITTLE_ENDIAN) - m_pos = op - 1; - m_pos -= (*(const unsigned short *)ip) >> 2; -#else - m_pos = op - 1; - m_pos -= (ip[0] >> 2) + (ip[1] << 6); -#endif + m_pos = op - 1 - (cpu_to_le16(*(const u16 *)ip) >> 2); (Andrey suggested le16_to_cpu for above but I think it should be cpu_to_le16). *** Need testing on big endian machine *** Similarly: -#if defined(__LITTLE_ENDIAN) - m_pos -= (*(const unsigned short *)ip) >> 2; -#else - m_pos -= (ip[0] >> 2) + (ip[1] << 6); -#endif + m_pos -= cpu_to_le16(*(const u16 *)ip) >> 2; 6) Get rid of LZO_CHECK_MPOS_NON_DET macro and PTR* macros. I think it's now ready for mainline inclusion. include/linux/lzo1x.h | 66 +++++++++++ lib/Kconfig | 6 + lib/Makefile | 2 + lib/lzo1x/Makefile | 2 + lib/lzo1x/lzo1x_compress.c | 259
tested this on ppc and its still good is there any reason to bother with a test on amd64? if there is I might be able to get to it tonight - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
