lkml.org 
[lkml]   [2017]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v7 0/5] Update LZ4 compressor module
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.

> 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.

Thanks,

Sven

\
 
 \ /
  Last update: 2017-02-09 11:58    [W:0.156 / U:1.496 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site