Re: [PATCH 11/11] cgroup: use percpu refcnt for cgroup_subsys_states

From: Tejun Heo
Date: Sat Jun 15 2013 - 01:35:47 EST


On Fri, Jun 14, 2013 at 03:31:25PM -0700, Tejun Heo wrote:
> I'll play with it a bit more on an actual machine and post more
> results. Test program attached.

So, here are the results from the same test on a dual-socket 2-way
NUMA opteron 8 core machine.

Running on one CPU.

copy size atomic percpu diff in pct
0 535964443 616756827 +15.07%
32 399988186 378678713 -5.33%
64 389067476 355073979 -8.74%
128 342192631 315615300 -7.77%
256 281208005 260598931 -7.33%
512 188070912 193225269 +2.74%

Running on all eight cores.

copy size atomic percpu diff in pct
0 121324328 4889425511 +3,930.05%
32 96170193 2999613380 +3,019.07%
64 98139061 2813894184 +2,767.25%
128 112610025 2503229487 +2,122.92%
256 96828114 2069865752 +2,037.67%
512 95858297 1537726109 +1,504.17%

Ration of all cores / single core.

copy size atomic percpu
0 0.23 7.93
32 0.24 7.92
64 0.25 7.92
128 0.33 7.93
256 0.34 7.94
512 0.51 7.96

Note exactly 8 - the cores do share quite a bit of resources after all
- but pretty close.

Thanks.

--
tejun
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