Re: [PATCH v4 2/4] zram: implement deduplication in zram

[Sergey Senozhatsky]

On (04/26/17 15:04), Joonsoo Kim wrote:
> On Wed, Apr 26, 2017 at 01:02:43PM +0900, Sergey Senozhatsky wrote:
> > On (04/26/17 09:52), js1304@xxxxxxxxx wrote:
> > [..]
> > > <no-dedup>
> > > Elapsed time: out/host: 88 s
> > > mm_stat: 8834420736 3658184579 3834208256 0 3834208256 32889 0 0 0
> > > 
> > > <dedup>
> > > Elapsed time: out/host: 100 s
> > > mm_stat: 8832929792 3657329322 2832015360 0 2832015360 32609 0 952568877 80880336
> > > 
> > > It shows performance degradation roughly 13% and save 24% memory. Maybe,
> > > it is due to overhead of calculating checksum and comparison.
> > 
> > I like the patch set, and it makes sense. the benefit is, obviously,
> > case-by-case. on my system I've managed to save just 60MB on a 2.7G
> > data set, which is far less than I was hoping to save :)
> > 
> > 
> > I usually do DIRECT IO fio performance test. JFYI, the results
> > were as follows:
> 
> Could you share your fio test setting? I will try to re-generate the
> result and analyze it.

sure.

I think I used this one: https://github.com/sergey-senozhatsky/zram-perf-test

// hm... may be slightly modified on my box.

I'll run more tests.



what I did:

#0
ZRAM_SIZE=2G ZRAM_COMP_ALG=lzo LOG_SUFFIX=NO-DEDUP FIO_LOOPS=2 ./zram-fio-test.sh

#1
add `echo 1 > /sys/block/zram0/use_dedup` to create_zram
ZRAM_SIZE=2G ZRAM_COMP_ALG=lzo LOG_SUFFIX=DEDUP FIO_LOOPS=2 ./zram-fio-test.sh


both in ./conf/fio-template-static-buffer fio config.

and then

#2
./fio-perf-o-meter.sh /tmp/test-fio-zram-NO-DEDUP /tmp/test-fio-zram-DEDUP > /tmp/RES

	-ss