Messages in this thread | | | Date | Wed, 15 Aug 2012 20:24:34 +0600 | Subject | Re: [discussion]sched: a rough proposal to enable power saving in scheduler | From | Rakib Mullick <> |
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On 8/13/12, Alex Shi <alex.shi@intel.com> wrote: > Since there is no power saving consideration in scheduler CFS, I has a > very rough idea for enabling a new power saving schema in CFS. > > It bases on the following assumption: > 1, If there are many task crowd in system, just let few domain cpus > running and let other cpus idle can not save power. Let all cpu take the > load, finish tasks early, and then get into idle. will save more power > and have better user experience. > This assumption indirectly point towards the scheme when performance is enabled, isn't it? Cause you're trying to spread the load equally amongst all the CPUs.
> 2, schedule domain, schedule group perfect match the hardware, and > the power consumption unit. So, pull tasks out of a domain means > potentially this power consumption unit idle. > How do you plan to test this power saving scheme? Using powertop? Or, is there any other tools?
> > select_task_rq_fair() > { > for_each_domain(cpu, tmp) { > if (policy == power && tmp_has_capacity && > tmp->flags & sd_flag) { > sd = tmp; > //It is fine to got cpu in the domain > break; > } > } > > while(sd) { > if policy == power > find_busiest_and_capable_group()
I'm not sure what find_busiest_and_capable_group() would really be, it seems it'll find the busiest and capable group, but isn't it a conflict with the first assumption you proposed on your proposal?
Thanks, Rakib.
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