Re: [discussion]sched: a rough proposal to enable power saving inscheduler

[Matthew Garrett]

On Fri, Aug 17, 2012 at 01:45:09PM -0600, Chris Friesen wrote:
> On 08/17/2012 12:47 PM, Matthew Garrett wrote:

> The datasheet for the Xeon E5 (my variant at least) says it doesn't
> do C7 so never powers down the LLC.  However, as you said earlier
> once you can put the socket into C6 which saves about 30W compared
> to C1E.
> 
> So as far as I can see with this CPU at least you would benefit from
> shutting down a whole socket when possible.

Having any active cores on the system prevents all packages from going 
into PC6 or deeper. What I'm not clear on is whether less deep package C 
states are also blocked.

-- 
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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