Re: [RFC][PATCH] page reclaim throttle take2

[KOSAKI Motohiro]

Hi

> One more thing, I would request you to add default heuristics (number of
> reclaimers), based on the number of cpus in the system. Letting people tuning it
> is fine, but defaults should be related to number of cpus, nodes and zones on
> the system. Zones can be reaped in parallel per node and cpus allow threads to
> run in parallel. So please use that to come up with good defaults, instead of a
> number like "3".

I don't think so.
all modern many cpu machine stand on NUMA.
it mean following,
 - if cpu increases, then zone increases, too.

if default value increase by #cpus, lock contension dramatically increase
on large numa.

Have I overlooked anything?


and, (but) i afraid to 3 is too small value.
if you have another test result on large machine, please show me.

- kosaki


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