On Thu, Feb 11, 2016 at 10:52:20AM -0800, Steve Muckle wrote: > On 02/11/2016 09:30 AM, Peter Zijlstra wrote: > >> My concern above is that pokes are guaranteed to keep occurring when > >> > there is only RT or DL activity so nothing breaks. > > > > The hook in their respective tick handler should ensure stuff is called > > sporadically and isn't stalled. > > But that's only true if the RT/DL tasks happen to be running when the > tick arrives right? > > Couldn't we have RT/DL activity which doesn't overlap with the tick? And > if no CFS tasks happen to be executing on that CPU, we'll never trigger > the cpufreq update. This could go on for an arbitrarily long time > depending on the periodicity of the work.
Possible yes, but why do we care? Such a CPU would be so much idle that cpufreq doesn't matter one way or another, right?
