Messages in this thread | | | Subject | Re: [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait or nmi | From | Peter Zijlstra <> | Date | Mon, 04 Jun 2012 22:33:21 +0200 |
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On Mon, 2012-06-04 at 22:11 +0200, Thomas Gleixner wrote:
> I understand what you are trying to do, though I completely disagree > with the solution. > > The main problem of the current hotplug code is that it is an all or > nothing approach. You have to tear down the whole thing completely > instead of just taking it out of the usable set of cpus. > > I'm working on a proper state machine driven online/offline sequence, > where you can put the cpu into an intermediate state which avoids > bringing it down completely. This is enough to get the full > powersaving benefits w/o having to go through all the synchronization > states of a full online/offline. That will shorten the onlining time > of an previously offlined cpu to almost nothing. > > I really want to avoid adding more bandaids to the hotplug code before > we have sorted out the existing horror.
Its far worse.. you shouldn't _ever_ care about hotplug latency unless you've got absolutely braindead hardware. We all now ARM has been particularly creative here, but is Intel now trying to trump ARM at stupid?
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