Messages in this thread | | | Date | Wed, 20 Feb 2013 20:39:20 +0800 | From | Alex Shi <> | Subject | Re: [patch v5 06/15] sched: log the cpu utilization at rq |
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On 02/20/2013 08:19 PM, Preeti U Murthy wrote: > Hi everyone, > > On 02/18/2013 10:37 AM, Alex Shi wrote: >> The cpu's utilization is to measure how busy is the cpu. >> util = cpu_rq(cpu)->avg.runnable_avg_sum >> / cpu_rq(cpu)->avg.runnable_avg_period; > > Why not cfs_rq->runnable_load_avg? I am concerned with what is the right > metric to use here.
Here we care the utilization of the cpu not the load avg. load avg maybe quit bigger on a heavy task(with a big load weight), but maybe it just used 20% of cpu time, while a light task with 100% cpu usage maybe still has smaller load avg.
For power consideration, above light task with 100% usage need to take a cpu, while another heavy task can packing into one cpu with other tasks.
> Refer to this discussion:https://lkml.org/lkml/2012/10/29/448 > > Regards > Preeti U Murthy >
-- Thanks Alex
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