Messages in this thread | | | From | Paul Turner <> | Date | Tue, 19 Jun 2012 01:47:57 -0700 | Subject | Re: [patch v3] sched: fix select_idle_sibling() induced bouncing |
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On Mon, Jun 11, 2012 at 10:22 AM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote: > On Mon, 2012-06-11 at 18:57 +0200, Mike Galbraith wrote: > >> Traversing an entire package is not only expensive, it also leads to tasks >> bouncing all over a partially idle and possible quite large package. Fix >> that up by assigning a 'buddy' CPU to try to motivate. Each buddy may try >> to motivate that one other CPU, if it's busy, tough, it may then try it's >> SMT sibling, but that's all this optimization is allowed to cost. >> >> Sibling cache buddies are cross-wired to prevent bouncing. >> >> Signed-off-by: Mike Galbraith <efault@gmx.de> > > The patch could do with a little comment on how you achieve the > cross-wiring because staring at the code I go cross-eyed again ;-) > > Anyway, I think I'll grab it since nobody seems to have any objections > and the numbers seem good. > > PJT any progress on your load-tracking stuff? Arjan is interested in the > avg runtime estimation it has to make the whole wake an idle thing > conditional on.
I'm still pretty much completely clobbered with internal stuff :( but it's on my agenda to put some cycles towards this week (and weekend). I'll say by Monday/Tuesday with a hopefully by-Friday.
We've gotten a lot of of test hours on it internally so I'm comfortable posting a non-RFC mergable series.
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