Re: [PATCH 3/3] context_tracking,x86: remove extraneous irq disable & enable from context tracking on syscall entry
From: Rik van Riel
Date: Sun May 03 2015 - 13:31:56 EST
On 05/03/2015 09:23 AM, Mike Galbraith wrote:
> Below are v4.1-rc1-172-g6c3c1eb3c35e + patches measurements.
>
> 100M * stat() on isolated cpu
>
> NO_HZ_FULL off inactive housekeeper nohz_full
> real 0m14.266s 0m14.367s 0m20.427s 0m27.921s
> user 0m1.756s 0m1.553s 0m1.976s 0m10.447s
> sys 0m12.508s 0m12.769s 0m18.400s 0m17.464s
> (real) 1.000 1.007 1.431 1.957
> 1.000 1.000
>
> real 0m20.423s 0m27.930s +rik 1,2
> user 0m2.072s 0m10.450s
> sys 0m18.304s 0m17.471s
> vs off 1.431 1.957
> vs prev 1.000 1.000
>
> real 0m20.256s 0m27.803s +paolo 1,2 (2 missing prototypes)
> user 0m1.884s 0m10.551s
> sys 0m18.353s 0m17.242s
> vs off 1.419 1.948
> vs prev .991 .995
>
> real 0m19.122s 0m26.946s +rik 3
> user 0m1.896s 0m10.292s
> sys 0m17.198s 0m16.644s
> vs off 1.340 1.888
> vs prev .944 .969
I'm convinced.
Time to try the remote sampling of CPU use statistics, and
lighten up the RCU overhead of context tracking.
I should be able to start on the remote sampling of CPU use
statistics this week.
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