On Wed, Mar 30, 2016 at 05:34:19PM +0900, Sergey Senozhatsky wrote: > Hello Minchan, > sorry for long reply. > > On (03/28/16 12:21), Minchan Kim wrote: > [..] > > group_reporting > > buffer_compress_percentage=50 > > filename=/dev/zram0 > > loops=10 > > 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? If we don't use buffer_compress_percentage, what's the content in the buffer? > > buffer_compress_percentage=int > If this is set, then fio will attempt to provide IO buffer content > (on WRITEs) that compress to the specified level. Fio does this by > providing a mix of random data and zeroes > > and I also used scramble_buffers=0. but default scramble_buffers is > true, so > > scramble_buffers=bool > If refill_buffers is too costly and the target is using data > deduplication, then setting this option will slightly modify the IO > buffer contents to defeat normal de-dupe attempts. This is not > enough to defeat more clever block compression attempts, but it will > stop naive dedupe of blocks. Default: true. > > 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. > > > > Hmm, Could you retest to who how the benefit is big? > > sure. the results are: > > - seq-read > - rand-read > - seq-write > - rand-write (READ + WRITE) > - mixed-seq > - mixed-rand (READ + WRITE) > > TEST 4 streams 8 streams per-cpu > > #jobs1 > READ: 2665.4MB/s 2515.2MB/s 2632.4MB/s > READ: 2258.2MB/s 2055.2MB/s 2166.2MB/s > WRITE: 933180KB/s 894260KB/s 898234KB/s > WRITE: 765576KB/s 728154KB/s 746396KB/s > READ: 563169KB/s 541004KB/s 551541KB/s > WRITE: 562660KB/s 540515KB/s 551043KB/s > READ: 493656KB/s 477990KB/s 488041KB/s > WRITE: 493210KB/s 477558KB/s 487600KB/s > #jobs2 > READ: 5116.7MB/s 4607.1MB/s 4401.5MB/s > READ: 4401.5MB/s 3993.6MB/s 3831.6MB/s > WRITE: 1539.9MB/s 1425.5MB/s 1600.0MB/s > WRITE: 1311.1MB/s 1228.7MB/s 1380.6MB/s > READ: 1001.8MB/s 960799KB/s 989.63MB/s > WRITE: 998.31MB/s 957540KB/s 986.26MB/s > READ: 921439KB/s 860387KB/s 899720KB/s > WRITE: 918314KB/s 857469KB/s 896668KB/s > #jobs3 > READ: 6670.9MB/s 6469.9MB/s 6548.8MB/s > READ: 5743.4MB/s 5507.8MB/s 5608.4MB/s > WRITE: 1923.8MB/s 1885.9MB/s 2191.9MB/s > WRITE: 1622.4MB/s 1605.4MB/s 1842.2MB/s > READ: 1277.3MB/s 1295.8MB/s 1395.2MB/s > WRITE: 1276.9MB/s 1295.4MB/s 1394.7MB/s > READ: 1152.6MB/s 1137.1MB/s 1216.6MB/s > WRITE: 1152.2MB/s 1137.6MB/s 1216.2MB/s > #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? 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? Thanks.
