Re: [slub shrink] 0f6934bf16: +191.9% vmstat.system.cs

From: Dave Hansen
Date: Thu Jan 16 2014 - 14:13:56 EST


On 01/15/2014 07:07 PM, kernel test robot wrote:
> 9a0bb2966efbf30 0f6934bf1695682e7ced973f6
> --------------- -------------------------
> 8235933 ~ 2% +80.6% 14872911 ~ 3% lkp-sbx04/micro/will-it-scale/read2
> 8235933 +80.6% 14872911 TOTAL interrupts.RES
>
> 9a0bb2966efbf30 0f6934bf1695682e7ced973f6
> --------------- -------------------------
> 161531 ~ 7% +191.9% 471544 ~ 9% lkp-sbx04/micro/will-it-scale/read2
> 161531 +191.9% 471544 TOTAL vmstat.system.cs
>
> 9a0bb2966efbf30 0f6934bf1695682e7ced973f6
> --------------- -------------------------
> 32943 ~ 1% +71.8% 56599 ~ 3% lkp-sbx04/micro/will-it-scale/read2
> 32943 +71.8% 56599 TOTAL vmstat.system.in

I suspect that something is wrong with that system. My 160-cpu system
does about 40,000 interrupts/sec and ~4300 context switches/sec when
running 160 read2_processes. I wonder if you're hitting swap or the
dirty limits or something. Are you running it with way more threads
than it has CPUs?

Also, are those will-it-scale tests the threaded or process versions?
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