Integrated: 8205051: Poor Performance with UseNUMA when cpu and memory nodes are misaligned

[Swati Sharma]

On Tue, 26 Nov 2024 17:25:03 GMT, Swati Sharma <duke at openjdk.org> wrote:

> Hi All,
> 
> The PR handles the performance issues related to flag UseNUMA. We disable the UseNUMA flag when the process gets invoked with incorrect node alignment.
> We check the cpunodebind and membind(or interleave for interleave policy) bitmask equality and disable UseNUMA when they are not equal.
> For example on a 4 NUMA node system:
> 0123 Node Number
> 1100  cpunodebind bitmask
> 1111 membind bitmask 
> Disable UseNUMA as CPU and memory bitmask are not equal.
> 
> 0123 Node Number  
> 1100  cpunodebind bitmask
> 1100 membind bitmask 
> Enable UseNUMA as CPU and memory bitmask are equal.
> 
> This covers all the cases with all policies and tested this with below command
> numactl --cpunodebind=0,1 --localalloc java -Xlog:gc*=info -XX:+UseParallelGC -XX:+UseNUMA -version
> 
> For localalloc and preferred policies the membind bitmask returns true for all nodes, hence if cpunodebind is not bound to all nodes then the UseNUMA will be disabled.
> 
> This PR covers disabling the UseNUMA flag for all GC's hence we observed an improvement of ~25% on G1GC , ~20% on ZGC and ~7-8% on PGC in both throughput  and latency on SPECjbb2015 on a 2 NUMA node SRF-SP system with 6Group configuration.
> 
> Please review and provide your valuable comments.
> 
> Thanks,
> Swati Sharma
> Intel

This pull request has now been integrated.

Changeset: 62a4544b
Author:    Swati Sharma <swati.sharma at intel.com>
Committer: Derek White <drwhite at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/62a4544bb76aa339a8129f81d2527405a1b1e7e3
Stats:     61 lines in 2 files changed: 48 ins; 3 del; 10 mod

8205051: Poor Performance with UseNUMA when cpu and memory nodes are misaligned

Co-authored-by: Derek White <drwhite at openjdk.org>
Reviewed-by: sjohanss, tschatzl

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PR: https://git.openjdk.org/jdk/pull/22395