On Tue, 26 Feb 2013, Markus F.X.J. Oberhumer wrote: > On 2013-02-26 07:24, Kyungsik Lee wrote: > > Hi, > > > > [...] > > > > Through the benchmark, it was found that -Os Compiler flag for > > decompress.o brought better decompression performance in most of cases > > (ex, different compiler and hardware spec.) in ARM architecture. > > > > Lastly, CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is not always the best > > option even though it is supported. The decompression speed can be > > slightly slower in some cases. > > > > This patchset is based on 3.8. > > > > Any comments are appreciated. > > Did you actually *try* the new LZO version and the patch (which is attached > once again) as explained in https://lkml.org/lkml/2013/2/3/367 ? > > Because the new LZO version is faster than LZ4 in my testing, at least > when comparing apples with apples and enabling unaligned access in > BOTH versions: > > armv7 (Cortex-A9), Linaro gcc-4.6 -O3, Silesia test corpus, 256 kB block-size: > > compression speed decompression speed > > LZO-2012 : 44 MB/sec 117 MB/sec no unaligned access > LZO-2013-UA : 47 MB/sec 167 MB/sec Unaligned Access > LZ4 r88 UA : 46 MB/sec 154 MB/sec Unaligned Access To be fair, you should also take into account the compressed size of a typical ARM kernel. Sometimes a slightly slower decompressor may be faster overall if the compressed image to work on is smaller. Nicolas -- 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
