Messages in this thread | | | Date | Fri, 27 Aug 2010 14:38:30 -0400 | From | Mathieu Desnoyers <> | Subject | Re: [RFC PATCH 00/11] sched: CFS low-latency features |
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* Mathieu Desnoyers (mathieu.desnoyers@efficios.com) wrote: > * Mike Galbraith (efault@gmx.de) wrote: > > On Fri, 2010-08-27 at 09:42 +0200, Peter Zijlstra wrote: > > > On Thu, 2010-08-26 at 19:49 -0400, Mathieu Desnoyers wrote: > > > > AFAIK, I don't think we would end up starving the system in any possible way. > > > > > > Correct, it does maintain fairness. > > > > > > > So far I cannot see a situation where selecting the next buddy would _not_ make > > > > sense in any kind of input-driven wakeups (interactive, timer, disk, network, > > > > etc). But maybe it's just a lack of imagination on my part. > > > > > > The risk is that you end up with always using next-buddy, and we tried > > > that a while back and that didn't work well for some, Mike might > > > remember. > > > > I turned it off because it was ripping spread apart badly, and last > > buddy did a better job of improving scalability without it. > > Maybe with the dyn min_vruntime feature proposed in this patchset we should > reconsider this. Spread being ripped apart is exactly what it addresses.
I'm curious: which workload was showing this kind of problem exactly ?
Thanks,
Mathieu
-- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com
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