Messages in this thread | | | Subject | Re: [PATCH 3/3] sched: Disable affine wakeups by default | From | Mike Galbraith <> | Date | Mon, 26 Oct 2009 05:38:27 +0100 |
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On Mon, 2009-10-26 at 02:53 +0100, Peter Zijlstra wrote: > On Sun, 2009-10-25 at 23:04 +0100, Mike Galbraith wrote: > > if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && > > - cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { > > + (level == SD_LV_SIBLING || level == SD_LV_MC)) { > > quick comment without actually having looked at the patch, we should > really get rid of sd->level and encode properties of the sched domains > in sd->flags.
Yeah, sounds right, while writing that, it looked kinda ugly. I suppose arch land needs to encode cache property somehow if I really want to be able to target cache on multicore. Booting becomes.. exciting when I tinker down there.
While tinkering with this, I noticed that when mysql+oltp starts tripping over itself, if you move to any momentarily idle cpu, it helps get the load moving again, the tail improves. Not hugely, but quite measurable. There seems to be benefit to be had throughout the load spectrum, just gotta figure out how to retrieve it without losing anything.
-Mike
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