Messages in this thread | | | Date | Mon, 04 Jun 2012 06:15:09 -0700 | From | Arjan van de Ven <> | Subject | Re: [PATCH] cpuidle: menu: use nr_running instead of cpuload for calculating perf mult |
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On 6/4/2012 3:24 AM, Vladimir Davydov wrote: > rq->cpuload strongly depends on cgroup hierarchy. For example, if hundreds of > tasks are running inside cpu:/test cgroup, the sum of cpuload over all cpus > won't exceed 1024 (by default). That makes the cpuidle menu governor take wrong > decisions, which can negatively affect overall performance.
nr_running is the wrong answer... it is instantaneous, not longer term. cpuidle wants a longer term, per cpu, notion of "busy", to use as proxy for performance sensitivity.
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