Messages in this thread | | | Date | Mon, 14 Feb 2022 15:57:07 +0530 | From | Srikar Dronamraju <> | Subject | Re: [PATCH 2/2] sched/fair: Adjust the allowed NUMA imbalance when SD_NUMA spans multiple LLCs |
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* Mel Gorman <mgorman@techsingularity.net> [2022-02-08 09:43:34]:
> Commit 7d2b5dd0bcc4 ("sched/numa: Allow a floating imbalance between NUMA > nodes") allowed an imbalance between NUMA nodes such that communicating > tasks would not be pulled apart by the load balancer. This works fine when > there is a 1:1 relationship between LLC and node but can be suboptimal > for multiple LLCs if independent tasks prematurely use CPUs sharing cache. > > Zen* has multiple LLCs per node with local memory channels and due to > the allowed imbalance, it's far harder to tune some workloads to run > optimally than it is on hardware that has 1 LLC per node. This patch > allows an imbalance to exist up to the point where LLCs should be balanced > between nodes. > > On a Zen3 machine running STREAM parallelised with OMP to have on instance > per LLC the results and without binding, the results are > > 5.17.0-rc0 5.17.0-rc0 >
Looks good to me.
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
-- Thanks and Regards Srikar Dronamraju
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