Re: sysbench throughput degradation in 4.13+

[Matt Fleming]

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%)