Messages in this thread | | | Date | Fri, 20 Nov 2015 10:45:14 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH 3/4] sched: introduce synchronized idle injection |
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On Thu, 19 Nov 2015, Peter Zijlstra wrote: > On Thu, Nov 19, 2015 at 05:24:07PM +0000, Morten Rasmussen wrote: > > I would consider it an > > emergency-only mechanism (as in emergency brake) that isn't really > > suitable for normal thermal management. In which case: Does this sort of > > mechanism belong in the scheduler code? > > I would prefer it not to be, but Thomas is very much opposed to teaching > the nohz code to 'work' on !idle threads.
The whole concept of faking idle is simply crap.
If you want to avoid that stuff in the scheduler, then create a mechanism which just defers the next timer interrupt for X milliseconds and does not any fiddling with NOHZ state and such.
That might hurt RT tasks, but if someone really cares about real-time and deterministic behaviour, then running the machine on its thermal limits is simply stupid. In fact any sensible RT system will bring itself into a safe state way before the machine runs into that condition.
Thanks,
tglx
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