Messages in this thread |  | | Date | Fri, 10 Oct 2014 11:14:41 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/7] sched: Introduce scale-invariant load tracking |
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On Wed, Oct 08, 2014 at 08:50:07AM +0800, Yuyang Du wrote: > Hi Morten, > > Sorry for late jumping in. > > The problem seems to be self-evident. But for the implementation to be > equally attractive it needs to account for every freq change for every task, > or anything less than that makes it less attractive.
I'm not entirely sure that is indeed required.
> But this should be very hard. Intel Architecture has limitation to capture all > the freq changes in software and also the intel_pstate should have no > notification.
So current Intel arch takes P-states as hints and then can mostly lower their actual frequency, right? In this case still accounting at the higher frequency is not a problem, the hardware conserves more power than we know, but that's the right kind of error to have :-)
For the full automatic hardware, that's basically hardware without DVFS capability so we should not bother at all and simply disable this scaling.
> For every task, this makes the updating of the entire queue in load tracking > more needed, so once again, ping maintainers for the rewrite patches, :)
Could you remind me what your latest version is; please reply to those patches with a new email so that I can more conveniently locate it.
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