Messages in this thread |  | | From | "Huang\, Ying" <> | Subject | Re: [PATCH RESEND] autonuma: Fix scan period updating | Date | Mon, 29 Jul 2019 11:04:58 +0800 |
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Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes:
> * Huang, Ying <ying.huang@intel.com> [2019-07-26 15:45:39]: > >> Hi, Srikar, >> >> > >> > More Remote + Private page Accesses: >> > Most likely the Private accesses are going to be local accesses. >> > >> > In the unlikely event of the private accesses not being local, we should >> > scan faster so that the memory and task consolidates. >> > >> > More Remote + Shared page Accesses: This means the workload has not >> > consolidated and needs to scan faster. So we need to scan faster. >> >> This sounds reasonable. But >> >> lr_ratio < NUMA_PERIOD_THRESHOLD >> >> doesn't indicate More Remote. If Local = Remote, it is also true. If > > less lr_ratio means more remote. > >> there are also more Shared, we should slow down the scanning. So, the > > Why should we slowing down if there are more remote shared accesses? > >> logic could be >> >> if (lr_ratio >= NUMA_PERIOD_THRESHOLD) >> slow down scanning >> else if (sp_ratio >= NUMA_PERIOD_THRESHOLD) { >> if (NUMA_PERIOD_SLOTS - lr_ratio >= NUMA_PERIOD_THRESHOLD) >> speed up scanning
Thought about this again. For example, a multi-threads workload runs on a 4-sockets machine, and most memory accesses are shared. The optimal situation will be pseudo-interleaving, that is, spreading memory accesses evenly among 4 NUMA nodes. Where "share" >> "private", and "remote" > "local". And we should slow down scanning to reduce the overhead.
What do you think about this?
Best Regards, Huang, Ying
>> else >> slow down scanning >> } else >> speed up scanning >> >> This follows your idea better? >> >> Best Regards, >> Huang, Ying
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