Hello Sven, On Thu, Feb 09, 2017 at 11:56:17AM +0100, Sven Schmidt wrote: > Hey Minchan, > > On Thu, Feb 09, 2017 at 08:31:21AM +0900, Minchan Kim wrote: > > 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% > > which parts of the output (as well as units) are these values exactly? > I did not work with fio until now, so I think I might ask before misinterpreting my results. It is IOPS. > > > 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 > > > > Great, this makes it easy for me to reproduce your test. If you have trouble to reproduce, feel free to ask me. I'm happy to test it. :) Thanks!
