Messages in this thread | | | Date | Wed, 12 Sep 2018 11:57:42 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 4/4] sched/numa: Do not move imbalanced load purely on the basis of an idle CPU |
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* Srikar Dronamraju <srikar@linux.vnet.ibm.com> wrote:
> * Mel Gorman <mgorman@techsingularity.net> [2018-09-10 10:41:47]: > > > On Fri, Sep 07, 2018 at 01:37:39PM +0100, Mel Gorman wrote: > > > > Srikar's patch here: > > > > > > > > http://lkml.kernel.org/r/1533276841-16341-4-git-send-email-srikar@linux.vnet.ibm.com > > > > > > > > Also frobs this condition, but in a less radical way. Does that yield > > > > similar results? > > > > > > I can check. I do wonder of course if the less radical approach just means > > > that automatic NUMA balancing and the load balancer simply disagree about > > > placement at a different time. It'll take a few days to have an answer as > > > the battery of workloads to check this take ages. > > > > > > > Tests completed over the weekend and I've found that the performance of > > both patches are very similar for two machines (both 2 socket) running a > > variety of workloads. Hence, I'm not worried about which patch gets picked > > up. However, I would prefer my own on the grounds that the additional > > complexity does not appear to get us anything. Of course, that changes if > > Srikar's tests on his larger ppc64 machines show the more complex approach > > is justified. > > > > Running SPECJbb2005. Higher bops are better. > > Kernel A = 4.18+ 13 sched patches part of v4.19-rc1. > Kernel B = Kernel A + 6 patches (http://lore.kernel.org/lkml/1533276841-16341-1-git-send-email-srikar@linux.vnet.ibm.com) > Kernel C = Kernel B - (Avoid task migration for small numa improvement) i.e > http://lore.kernel.org/lkml/1533276841-16341-4-git-send-email-srikar@linux.vnet.ibm.com > + 2 patches from Mel > (Do not move imbalanced load purely) > http://lore.kernel.org/lkml/20180907101139.20760-5-mgorman@techsingularity.net > (Stop comparing tasks for NUMA placement) > http://lore.kernel.org/lkml/20180907101139.20760-4-mgorman@techsingularity.net
We absolutely need the 'best' pre-regression baseline kernel measurements as well - was it vanilla v4.17?
Thanks,
Ingo
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