Messages in this thread | | | Date | Fri, 08 Mar 2013 10:37:23 +0800 | From | Michael Wang <> | Subject | Re: [PATCH] sched: wakeup buddy |
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On 03/07/2013 05:43 PM, Mike Galbraith wrote: > On Thu, 2013-03-07 at 09:36 +0100, Peter Zijlstra wrote: >> On Wed, 2013-03-06 at 15:06 +0800, Michael Wang wrote: >> >>> wake_affine() stuff is trying to bind related tasks closely, but it doesn't >>> work well according to the test on 'perf bench sched pipe' (thanks to Peter). >> >> so sched-pipe is a poor benchmark for this.. >> >> Ideally we'd write a new benchmark that has some actual data footprint >> and we'd measure the cost of tasks being apart on the various cache >> metrics and see what affine wakeup does for it. >> >> Before doing something like what you're proposing, I'd have a hard look >> at WF_SYNC, it is possible we should disable/fix select_idle_sibling >> for sync wakeups. > > If nobody beats me to it, I'm going to try tracking shortest round trip > to idle, and use a multiple of that to shut select_idle_sibling() down. > If avg_idle approaches round trip time, there's no win to be had, we're > just wasting cycles.
That's great if we have it, I'm a little doubt whether it is possible to find a better way to replace the select_idle_sibling() (look at the way it locates idle cpu...) in some cases, but I'm looking forward it ;-)
Regards, Michael Wang
> > -Mike > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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