Messages in this thread | | | Subject | Re: [PATCH] sched: wake-affine throttle | From | Mike Galbraith <> | Date | Thu, 11 Apr 2013 11:00:40 +0200 |
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On Thu, 2013-04-11 at 10:44 +0200, Mike Galbraith wrote: > On Thu, 2013-04-11 at 16:26 +0800, Michael Wang wrote: > > > The 1:N is a good reason to explain why the chance that wakee's hot data > > cached on curr_cpu is lower, and since it's just 'lower' not 'extinct', > > after the throttle interval large enough, it will be balanced, this > > could be proved, since during my test, when the interval become too big, > > the improvement start to drop. > > Magnitude of improvement drops just because there's less damage done > methinks. You'll eventually run out of measurable damage :) > > Yes, it's not really extinct, you _can_ reap a gain, it's just not at > all likely to work out. A more symetric load will fare better, but any > 1:N thing just has to spread far and wide to have any chance to perform. > > Hmm...that's an interesting point, the workload contain different > > 'priority' works, and depend on each other, if mother starving, all the > > kids could do nothing but wait for her, may be that's the reason why the > > benefit is so significant, since in such case, mother's little quicker > > respond will make all the kids happy :) > > Exactly. The entire load is server latency bound. Keep the server on > cpu, the load performs as best it can given unavoidable data miss cost.
(ie serial producer, parallel consumer... choke point lies with utterly unscalable serial work producer)
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