Re: sysbench throughput degradation in 4.13+

Matt Fleming
2017-10-02T22:53:19Z

On Wed, 27 Sep, at 01:58:20PM, Rik van Riel wrote:
>
> I like the simplicity of your approach! I hope it does not break
> stuff like netperf...
>
> I have been working on the patch below, which is much less optimistic
> about when to do an affine wakeup than before.

Running netperf for this patch and Peter's patch shows that Peter's
comes out on top, with scores pretty close to v4.12 in most places on
my 2-NUMA node 48-CPU Xeon box.

I haven't dug any further into why v4.13-peterz+ is worse than v4.12,
but I will next week.

netperf-tcp
4.12.0 4.13.0 4.13.0 4.13.0
default default peterz+ riel+
Min 64 1653.72 ( 0.00%) 1554.29 ( -6.01%) 1601.71 ( -3.15%) 1627.01 ( -1.62%)
Min 128 3240.96 ( 0.00%) 2858.49 ( -11.80%) 3122.62 ( -3.65%) 3063.67 ( -5.47%)
Min 256 5840.55 ( 0.00%) 4077.43 ( -30.19%) 5529.98 ( -5.32%) 5362.18 ( -8.19%)
Min 1024 16812.11 ( 0.00%) 11899.72 ( -29.22%) 16335.83 ( -2.83%) 15075.24 ( -10.33%)
Min 2048 26875.79 ( 0.00%) 18852.35 ( -29.85%) 25902.85 ( -3.62%) 22804.82 ( -15.15%)
Min 3312 33060.18 ( 0.00%) 20984.28 ( -36.53%) 32817.82 ( -0.73%) 29161.49 ( -11.79%)
Min 4096 34513.24 ( 0.00%) 23253.94 ( -32.62%) 34167.80 ( -1.00%) 29349.09 ( -14.96%)
Min 8192 39836.88 ( 0.00%) 28881.63 ( -27.50%) 39613.28 ( -0.56%) 35307.95 ( -11.37%)
Min 16384 44203.84 ( 0.00%) 31616.74 ( -28.48%) 43608.86 ( -1.35%) 38130.44 ( -13.74%)
Hmean 64 1686.58 ( 0.00%) 1613.25 ( -4.35%) 1657.04 ( -1.75%) 1655.38 ( -1.85%)
Hmean 128 3361.84 ( 0.00%) 2945.34 ( -12.39%) 3173.47 ( -5.60%) 3122.38 ( -7.12%)
Hmean 256 5993.92 ( 0.00%) 4423.32 ( -26.20%) 5618.26 ( -6.27%) 5523.72 ( -7.84%)
Hmean 1024 17225.83 ( 0.00%) 12314.23 ( -28.51%) 16574.85 ( -3.78%) 15644.71 ( -9.18%)
Hmean 2048 27944.22 ( 0.00%) 21301.63 ( -23.77%) 26395.38 ( -5.54%) 24067.57 ( -13.87%)
Hmean 3312 33760.48 ( 0.00%) 22361.07 ( -33.77%) 33198.32 ( -1.67%) 30055.64 ( -10.97%)
Hmean 4096 35077.74 ( 0.00%) 29153.73 ( -16.89%) 34479.40 ( -1.71%) 31215.64 ( -11.01%)
Hmean 8192 40674.31 ( 0.00%) 33493.01 ( -17.66%) 40443.22 ( -0.57%) 37298.58 ( -8.30%)
Hmean 16384 45492.12 ( 0.00%) 37177.64 ( -18.28%) 44308.62 ( -2.60%) 40728.33 ( -10.47%)
Max 64 1745.95 ( 0.00%) 1649.03 ( -5.55%) 1710.52 ( -2.03%) 1702.65 ( -2.48%)
Max 128 3509.96 ( 0.00%) 3082.35 ( -12.18%) 3204.19 ( -8.71%) 3174.41 ( -9.56%)
Max 256 6138.35 ( 0.00%) 4687.62 ( -23.63%) 5694.52 ( -7.23%) 5722.08 ( -6.78%)
Max 1024 17732.13 ( 0.00%) 13270.42 ( -25.16%) 16838.69 ( -5.04%) 16580.18 ( -6.50%)
Max 2048 28907.99 ( 0.00%) 24816.39 ( -14.15%) 26792.86 ( -7.32%) 25003.60 ( -13.51%)
Max 3312 34512.60 ( 0.00%) 23510.32 ( -31.88%) 33762.47 ( -2.17%) 31676.54 ( -8.22%)
Max 4096 35918.95 ( 0.00%) 35245.77 ( -1.87%) 34866.23 ( -2.93%) 32537.07 ( -9.42%)
Max 8192 41749.55 ( 0.00%) 41068.52 ( -1.63%) 42164.53 ( 0.99%) 40105.50 ( -3.94%)
Max 16384 47234.74 ( 0.00%) 41728.66 ( -11.66%) 45387.40 ( -3.91%) 44107.25 ( -6.62%)