Messages in this thread | | | Date | Tue, 10 Jan 2012 10:18:05 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] x86,sched: Fix sched_smt_power_savings totally broken |
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* Suresh Siddha <suresh.b.siddha@intel.com> wrote:
> On Tue, 2012-01-10 at 00:58 -0500, Youquan Song wrote: > > Thanks Peter! Here is the patch. > > Youquan, As far as I know both the > sched_smt_power_savings/sched_mc_power_savings are broken for atleast an > year.
We want a single knob, sched_power_savings - with the mc_ and smt_ ones still kept and aliased to sched_power_savings, for compatibility reasons.
As Peter said, the other reasonable option is to have no knob at all and restart this code from scratch.
The other thing we should do is to add sane defaults: to turn on sched_power_savings *AUTOMATICALLY* when a system is obviously battery driven and turn it off when the system is obviously AC driven. User-space can still implement policy and override the kernel's default, but there's absolutely no excuse to not offer this default ourselves.
The kernel default should probably change automatically on powerloss and battery events as well. (again, if user-space wants to do it itself, it can do it and we won't interfere.)
Thanks,
Ingo
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