Re: [PATCH 2/2] sched/numa: Delay retrying placement for automatic NUMA balance after wake_affine

From: Peter Zijlstra
Date: Mon Feb 12 2018 - 12:35:24 EST


On Mon, Feb 12, 2018 at 05:11:31PM +0000, Mel Gorman wrote:

> However, the benefit in other cases is large. This is the result for NAS
> with the D class sizing on a 4-socket machine
>
> 4.15.0 4.15.0
> sdnuma-v1r23 delayretry-v1r23
> Time cg.D 557.00 ( 0.00%) 431.82 ( 22.47%)
> Time ep.D 77.83 ( 0.00%) 79.01 ( -1.52%)
> Time is.D 26.46 ( 0.00%) 26.64 ( -0.68%)
> Time lu.D 727.14 ( 0.00%) 597.94 ( 17.77%)
> Time mg.D 191.35 ( 0.00%) 146.85 ( 23.26%)

Last time I checked, we were some ~25% from OMP_PROC_BIND with NAS, this
seems to close that hole significantly. Do you happen to have
OMP_PROC_BIND numbers handy to see how far away we are from manual
affinity?