Messages in this thread | | | Date | Tue, 5 May 2009 21:57:01 +1000 | From | Paul Mackerras <> | Subject | Re: round-robining per-cpu counters |
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Ingo Molnar writes:
> The reservation mechanism really suffered from not being used by > anything or anyone, and it thus bit-rotted across 300 follow-on > commits.
Yeah.
> What would be the primary usecase? Allow admin to set aside (and > guarantee) space for task counters? Allow admin to 'force' > exclusivity of counter ownership? > > I think a better general solution would be to have a single > round-robin list for all currently active counters (both percpu and > task counters) - and fairly round-robin all of them. The scaling > information makes it obvious when this is happening.
Sounds good, but I'm having trouble visualizing how we combine a fairly static set of per-cpu counters with several sets of per-task counters that come and go as their tasks get scheduled in and out. Is there some clever scheduling technique that sorts all that out?
> If admin wants stronger ownership of counters then the > pinned/exclusive attribute can be used.
I agree.
> We really want to keep the counter-scheduler simple, and we also > want to make the default to be as permissive as possible.
Definitely.
Paul.
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