Messages in this thread | | | Date | Thu, 31 Mar 2016 10:26:26 +0900 | From | Sergey Senozhatsky <> | Subject | Re: zram: per-cpu compression streams |
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Hello,
On (03/31/16 07:12), Minchan Kim wrote: [..] > > I used a bit different script. no `buffer_compress_percentage' option, > > because it provide "a mix of random data and zeroes" > > Normally, zram's compression ratio is 3 or 2 so I used it. > Hmm, isn't it more real practice usecase?
this option guarantees that the supplied to zram data will have a requested compression ratio? hm, but we never do that in real life, zram sees random data.
> If we don't use buffer_compress_percentage, what's the content in the buffer?
that's a good question. I quickly looked into the fio source code, we need to use "buffer_pattern=str" option, I think. so the buffers will be filled with the same data.
I don't mind to have buffer_compress_percentage as a separate test (set as a local test option), but I think that using common buffer pattern adds more confidence when we compare test results.
[..] > > hm, but I guess it's not enough; fio probably will have different > > data (well, only if we didn't ask it to zero-fill the buffers) for > > different tests, causing different zram->zsmalloc behaviour. need > > to check it. [..] > > #jobs4 > > READ: 8720.4MB/s 7301.7MB/s 7896.2MB/s > > READ: 7510.3MB/s 6690.1MB/s 6456.2MB/s > > WRITE: 2211.6MB/s 1930.8MB/s 2713.9MB/s > > WRITE: 2002.2MB/s 1629.8MB/s 2227.7MB/s > > Your case is 40% win. It's huge, Nice! > I tested with your guide line(i.e., no buffer_compress_percentage, > scramble_buffers=0) but still 10% enhance in my machine. > Hmm,,, > > How about if you test my fio job.file in your machine? > Still, it's 40% win?
I'll retest with new config.
> Also, I want to test again in your exactly same configuration. > Could you tell me zram environment(ie, disksize, compression > algorithm) and share me your job.file of fio?
sure.
3G, lzo
--- my fio-template is
[global] bs=4k ioengine=sync direct=1 size=__SIZE__ numjobs=__JOBS__ group_reporting filename=/dev/zram0 loops=1 buffer_pattern=0xbadc0ffee scramble_buffers=0
[seq-read] rw=read stonewall
[rand-read] rw=randread stonewall
[seq-write] rw=write stonewall
[rand-write] rw=randwrite stonewall
[mixed-seq] rw=rw stonewall
[mixed-rand] rw=randrw stonewall
#separate test with #buffer_compress_percentage=50
--- my create-zram script is as follows.
#!/bin/sh
rmmod zram modprobe zram
if [ -e /sys/block/zram0/initstate ]; then initdone=`cat /sys/block/zram0/initstate` if [ $initdone = 1 ]; then echo "init done" exit 1 fi fi
echo 8 > /sys/block/zram0/max_comp_streams
echo lzo > /sys/block/zram0/comp_algorithm cat /sys/block/zram0/comp_algorithm
cat /sys/block/zram0/max_comp_streams echo $1 > /sys/block/zram0/disksize
--- and I use it as
#!/bin/sh
DEVICE_SZ=$((3 * 1024 * 1024 * 1024)) FREE_SPACE=$(($DEVICE_SZ / 10)) LOG=/tmp/fio-zram-test LOG_SUFFIX=$1
function reset_zram { rmmod zram }
function create_zram { ./create-zram $DEVICE_SZ }
function main { local j local i
if [ "z$LOG_SUFFIX" = "z" ]; then LOG_SUFFIX="UNSET" fi
LOG=$LOG-$LOG_SUFFIX
for i in {1..10}; do reset_zram create_zram
cat fio-test-template | sed s/__JOBS__/$i/ | sed s/__SIZE__/$((($DEVICE_SZ/$i - $FREE_SPACE)/(1024*1024)))M/ > fio-test echo "#jobs$i" >> $LOG time fio ./fio-test >> $LOG done
reset_zram }
main
-- then I use this simple script
#!/bin/sh
if [ "z$2" = "z" ]; then cat $1 | egrep "#jobs|READ|WRITE" | awk '{printf "%-15s %15s\n", $1, $3}' | sed s/aggrb=// | sed s/,// else cat $1 | egrep "#jobs|READ|WRITE" | awk '{printf " %-15s\n", $3}' | sed s/aggrb=// | sed s/\#jobs[0-9]*// | sed s/,// fi
as
./squeeze.sh fio-zram-test-4-stream > 4s ./squeeze.sh fio-zram-test-8-stream A > 8s ./squeeze.sh fio-zram-test-per-cpu A > pc
and
paste 4s 8s pc > result
-ss
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