Hello Sven, On Sun, Feb 05, 2017 at 08:09:03PM +0100, Sven Schmidt wrote: > > This patchset is for updating the LZ4 compression module to a version based > on LZ4 v1.7.3 allowing to use the fast compression algorithm aka LZ4 fast > which provides an "acceleration" parameter as a tradeoff between > high compression ratio and high compression speed. > > We want to use LZ4 fast in order to support compression in lustre > and (mostly, based on that) investigate data reduction techniques in behalf of > storage systems. > > Also, it will be useful for other users of LZ4 compression, as with LZ4 fast > it is possible to enable applications to use fast and/or high compression > depending on the usecase. > For instance, ZRAM is offering a LZ4 backend and could benefit from an updated > LZ4 in the kernel. > > LZ4 homepage: http://www.lz4.org/ > LZ4 source repository: https://github.com/lz4/lz4 > Source version: 1.7.3 > > Benchmark (taken from [1], Core i5-4300U @1.9GHz): > ----------------|--------------|----------------|---------- > Compressor | Compression | Decompression | Ratio > ----------------|--------------|----------------|---------- > memcpy | 4200 MB/s | 4200 MB/s | 1.000 > LZ4 fast 50 | 1080 MB/s | 2650 MB/s | 1.375 > LZ4 fast 17 | 680 MB/s | 2220 MB/s | 1.607 > LZ4 fast 5 | 475 MB/s | 1920 MB/s | 1.886 > LZ4 default | 385 MB/s | 1850 MB/s | 2.101 > > [1] http://fastcompression.blogspot.de/2015/04/sampling-or-faster-lz4.html > > [PATCH 1/5] lib: Update LZ4 compressor module > [PATCH 2/5] lib/decompress_unlz4: Change module to work with new LZ4 module version > [PATCH 3/5] crypto: Change LZ4 modules to work with new LZ4 module version > [PATCH 4/5] fs/pstore: fs/squashfs: Change usage of LZ4 to work with new LZ4 version > [PATCH 5/5] lib/lz4: Remove back-compat wrappers Today, I did zram-lz4 performance test with fio in current mmotm and found it makes regression about 20%. "lz4-update" means current mmots(git://git.cmpxchg.org/linux-mmots.git) so applied your 5 patches. (But now sure current mmots has recent uptodate patches) "revert" means I reverted your 5 patches in current mmots. revert lz4-update seq-write 1547 1339 86.55% rand-write 22775 19381 85.10% seq-read 7035 5589 79.45% rand-read 78556 68479 87.17% mixed-seq(R) 1305 1066 81.69% mixed-seq(W) 1205 984 81.66% mixed-rand(R) 17421 14993 86.06% mixed-rand(W) 17391 14968 86.07% My fio description file [global] bs=4k ioengine=sync size=100m numjobs=1 group_reporting buffer_compress_percentage=30 scramble_buffers=0 filename=/dev/zram0 loops=10 fsync_on_close=1 [seq-write] bs=64k rw=write stonewall [rand-write] rw=randwrite stonewall [seq-read] bs=64k rw=read stonewall [rand-read] rw=randread stonewall [mixed-seq] bs=64k rw=rw stonewall [mixed-rand] rw=randrw stonewall
