Messages in this thread | | | From | "Huang, Ying" <> | Subject | Re: [PATCH -V3 2/2 UPDATE] NUMA balancing: avoid to migrate task to CPU-less node | Date | Wed, 16 Mar 2022 08:37:51 +0800 |
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Hi, Peter,
"Huang, Ying" <ying.huang@intel.com> writes:
> Hi, Peter, > > "Huang, Ying" <ying.huang@intel.com> writes: > >> In a typical memory tiering system, there's no CPU in slow (PMEM) NUMA >> nodes. But if the number of the hint page faults on a PMEM node is >> the max for a task, The current NUMA balancing policy may try to place >> the task on the PMEM node instead of DRAM node. This is unreasonable, >> because there's no CPU in PMEM NUMA nodes. To fix this, CPU-less >> nodes are ignored when searching the migration target node for a task >> in this patch. >> >> To test the patch, we run a workload that accesses more memory in PMEM >> node than memory in DRAM node. Without the patch, the PMEM node will >> be chosen as preferred node in task_numa_placement(). While the DRAM >> node will be chosen instead with the patch. >> >> Known issue: I don't have systems to test complex NUMA topology type, >> for example, NUMA_BACKPLANE or NUMA_GLUELESS_MESH. >> >> v3: >> >> - Fix a boot crash for some uncovered marginal condition. Thanks Qian >> Cai for reporting and testing the bug! >> >> - Fix several missing places to use CPU-less nodes as migrating >> target. >> >> Signed-off-by: "Huang, Ying" <ying.huang@intel.com> >> Reported-and-tested-by: Qian Cai <quic_qiancai@quicinc.com> # boot crash >> Cc: Peter Zijlstra <peterz@infradead.org> >> Cc: Valentin Schneider <valentin.schneider@arm.com> >> Cc: Ingo Molnar <mingo@redhat.com> >> Cc: Mel Gorman <mgorman@suse.de> >> Cc: Rik van Riel <riel@surriel.com> >> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > Can you update the patch to fix the bug? Or you prefer the incremental > patch?
Can you take a look at this?
Best Regards, Huang, Ying
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