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 | Tue, 08 Mar 2022 10:11:11 +0800 |
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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?
Best Regards, Huang, Ying
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