Messages in this thread | | | Date | Thu, 21 Feb 2013 09:43:11 +0800 | From | Alex Shi <> | Subject | Re: [patch v5 04/15] sched: add sched balance policies in kernel |
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On 02/20/2013 11:41 PM, Ingo Molnar wrote: > > * Alex Shi <alex.shi@intel.com> wrote: > >> Now there is just 2 types policy: performance and >> powersaving(with 2 degrees, powersaving and balance). > > I don't think we really want to have 'degrees' to the policies > at this point - we want each policy to be extremely good at what > it aims to do: > > - 'performance' should finish jobs in in the least amount of > time possible. No ifs and whens. > > - 'power saving' should finish jobs with the least amount of > watts consumed. No ifs and whens. > >> powersaving policy will try to assign one task to each LCPU, >> whichever the LCPU is SMT thread or a core. The balance policy >> is also a kind of powersaving policy, just a bit less >> aggressive. It will try to assign tasks according group >> capacity, one task to one capacity. > > The thing is, 'a bit less aggressive' is an awfully vague > concept to maintain on a long term basis - while the two > definitions above are reasonably deterministic which can be > measured and improved upon. > > Those two policies and definitions are also much easier to > communicate to user-space and to users - it's much easier to > explain what each policy is supposed to do. > > I'd be totally glad if we got so far that those two policies > work really well. Any further nuance visible at the ABI level is > I think many years down the road - if at all. Simple things > first - those are complex enough already.
Thanks for comments! I will remove the 'balance' policy.
> > Thanks, > > Ingo >
-- Thanks Alex
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