RE: [PATCH 0/10] bulk cpu removal support

[Protasevich, Natalie]

> Per Ashok's request here is some data on offlining with 
> cpu_bulk_remove vs. sequentially with a shell script.
> I had 64x system (physical CPU) and 128 (those 64 
> hyperthreaded). The system was idle. 
> Elapsed times are not strikingly different but system/user times are:
> 
>                 64 CPU                                        
>   128 CPU
> (64 physical hyperthreaded)
>                 cpu_bulk_remove         shell script
> cpu_bulk_remove         shell script
> all offline     real    0m11.231s       real    0m10.775s       real
> 0m26.973s       real    0m16.484s
>                 user    0m0.000s        user    0m0.056         user
> 0m0.000s        user    0m0.068s
>                 sys     0m0.072s        sys     0m0.448         sys
> 0m0.132s        sys     0m1.312s
> 
>                 real    0m11.977s       real    0m10.550s       real
> 0m28.978s       real    0m14.259s
>                 user    0m0.000s        user    0m0.064s        user
> 0m0.000s        user    0m0.060s
>                 sys     0m0.032s        sys     0m0.464s        sys
> 0m0.152s        sys     0m1.432s
> 
> 32 offline      real    0m1.320s        real    0m2.422s        real
> 0m1.647s        real    0m1.896s
>                 user    0m0.000s        user    0m0.000s        user
> 0m0.000s        user    0m0.020s
>                 sys     0m0.076s        sys     0m0.232s        sys
> 0m0.096s        sys     0m0.456s
> 
>                 real    0m1.407s        real    0m3.348s        real
> 0m0.418s        real    0m1.198s
>                 user    0m0.000s        user    0m0.012s        user
> 0m0.000s        user    0m0.008s
>                 sys     0m0.072s        sys     0m0.276s        sys
> 0m0.044s        sys     0m0.244s
> 
> groups of 16    real 0m5.877s           real 0m11.403s
>                 user 0m0.000s           user 0m0.024s
>                 sys 0m0.140s            sys 0m0.408s
> 
> groups of 8     real 0m8.847s           real 0m12.078s          real
> 0m12.311s       real    0m12.736s
>                 user 0m0.004s           user 0m0.028s           user
> 0m0.004s        user    0m0.076s
>                 sys 0m0.232s            sys 0m0.536s            sys
> 0m0.448s        sys     0m1.448s
> 
>                                                                 real
> 0m11.968s       real    0m14.314s
>                                                                 user
> 0m0.008s        user    0m0.084s
>                                                                 sys
> 0m0.400s        sys     0m1.492s
> 
> With smaller "bulks" cpu_bulk_remove is always better, but 
> with large ones shell script mostly wins, especially with 
> hyperthreading (despite of much better system and user times!)
> 
Oops it all wrapped :O 
I'm attaching the data file instead, sorry about that.

--Natalie
>

Attachment: cpu_data
Description: cpu_data