Re: zram: per-cpu compression streams

From: Sergey Senozhatsky
Date: Wed Apr 27 2016 - 05:00:18 EST


On (04/27/16 17:54), Sergey Senozhatsky wrote:
> #jobs4
> READ: 19948MB/s 20013MB/s
> READ: 17732MB/s 17479MB/s
> WRITE: 630690KB/s 495078KB/s
> WRITE: 1843.2MB/s 2226.9MB/s
> READ: 1603.4MB/s 1846.8MB/s
> WRITE: 1599.4MB/s 1842.2MB/s
> READ: 1547.7MB/s 1740.7MB/s
> WRITE: 1549.2MB/s 1742.4MB/s

> jobs4
> stalled-cycles-frontend 265,519,049,536 ( 64.46%) 221,049,841,649 ( 61.81%)
> stalled-cycles-backend 146,538,881,296 ( 35.57%) 113,774,053,039 ( 31.82%)
> instructions 298,241,854,695 ( 0.72) 278,000,866,874 ( 0.78)
> branches 59,531,800,053 ( 400.919) 55,096,944,109 ( 427.816)
> branch-misses 285,108,083 ( 0.48%) 260,972,185 ( 0.47%)

> seconds elapsed 47.816933840 52.966896478

per-cpu in general looks better in this test (jobs4): less stalls, less
branches, less misses, better fio speeds (except for WRITE: 630690KB/s 495078KB/s).
the system was under pressure, so quite possible that it took more time to kill the
process, thus execution time is in favor of 8 streams test.

-ss