Re: [PATCH 05/19] sched/numa: Use task faults only if numa_group is not yet setup

Peter Zijlstra
2018-06-04T12:24:27Z

On Mon, Jun 04, 2018 at 03:30:14PM +0530, Srikar Dronamraju wrote:
> When numa_group faults are available, task_numa_placement only uses
> numa_group faults to evaluate preferred node. However it still accounts
> task faults and even evaluates the preferred node just based on task
> faults just to discard it in favour of preferred node chosen on the
> basis of numa_group.
>
> Instead use task faults only if numa_group is not set.
>
> Testcase Time: Min Max Avg StdDev
> numa01.sh Real: 506.35 794.46 599.06 104.26
> numa01.sh Sys: 150.37 223.56 195.99 24.94
> numa01.sh User: 43450.69 61752.04 49281.50 6635.33
> numa02.sh Real: 60.33 62.40 61.31 0.90
> numa02.sh Sys: 18.12 31.66 24.28 5.89
> numa02.sh User: 5203.91 5325.32 5260.29 49.98
> numa03.sh Real: 696.47 853.62 745.80 57.28
> numa03.sh Sys: 85.68 123.71 97.89 13.48
> numa03.sh User: 55978.45 66418.63 59254.94 3737.97
> numa04.sh Real: 444.05 514.83 497.06 26.85
> numa04.sh Sys: 230.39 375.79 316.23 48.58
> numa04.sh User: 35403.12 41004.10 39720.80 2163.08
> numa05.sh Real: 423.09 460.41 439.57 13.92
> numa05.sh Sys: 287.38 480.15 369.37 68.52
> numa05.sh User: 34732.12 38016.80 36255.85 1070.51
>
> Testcase Time: Min Max Avg StdDev %Change
> numa01.sh Real: 478.45 565.90 515.11 30.87 16.29%
> numa01.sh Sys: 207.79 271.04 232.94 21.33 -15.8%
> numa01.sh User: 39763.93 47303.12 43210.73 2644.86 14.04%
> numa02.sh Real: 60.00 61.46 60.78 0.49 0.871%
> numa02.sh Sys: 15.71 25.31 20.69 3.42 17.35%
> numa02.sh User: 5175.92 5265.86 5235.97 32.82 0.464%
> numa03.sh Real: 776.42 834.85 806.01 23.22 -7.47%
> numa03.sh Sys: 114.43 128.75 121.65 5.49 -19.5%
> numa03.sh User: 60773.93 64855.25 62616.91 1576.39 -5.36%
> numa04.sh Real: 456.93 511.95 482.91 20.88 2.930%
> numa04.sh Sys: 178.09 460.89 356.86 94.58 -11.3%
> numa04.sh User: 36312.09 42553.24 39623.21 2247.96 0.246%
> numa05.sh Real: 393.98 493.48 436.61 35.59 0.677%
> numa05.sh Sys: 164.49 329.15 265.87 61.78 38.92%
> numa05.sh User: 33182.65 36654.53 35074.51 1187.71 3.368%
>
> Ideally this change shouldn't have affected performance.

Ideally you go on here to explain why it does in fact do affect
performance.. :-)