Messages in this thread | | | Subject | Re: [RFC][PATCH 25/26] sched, numa: Only migrate long-running entities | From | Peter Zijlstra <> | Date | Mon, 09 Jul 2012 16:55:58 +0200 |
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On Mon, 2012-07-09 at 10:53 -0400, Rik van Riel wrote: > On 07/09/2012 08:26 AM, Peter Zijlstra wrote: > > On Sun, 2012-07-08 at 14:34 -0400, Rik van Riel wrote: > > >> Do we really want to calculate the amount of CPU time used > >> by a process, and start migrating after just one second? > >> > >> Or would it be ok to start migrating once a process has > >> been scanned once or twice by the NUMA code? > > > > You mean, the 2-3rd time we try and migrate this task, not the memory > > scanning thing as per Andrea, right? > > Indeed. That way we can simply keep a flag somewhere, > instead of iterating over the threads in a process.
Note that the code in -tip needs to iterate over all tasks in order to test all cpus_allowed and mems_allowed masks. But we could keep a process wide intersection of those masks around as well I guess, updating them is a slow path anyway.
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