On Wed, Nov 18, 2015 at 11:35:41AM +0100, Peter Zijlstra wrote: > On Wed, Nov 18, 2015 at 09:36:22AM +0100, Ingo Molnar wrote: > > What will such throttling do to latencies, as observed by user-space tasks? > > What's > > the typical expected frequency of the throttling frequency that you are > > targeting? > > The default has 5ms (iirc) of forced idle, so depending on what you do, > noticeable to outright painful.
IIUC, it is 5 ticks, not ms. Which raises the question, doesn't that mean that we get disturbed four times on each cpu during the forced idle period? So idle injection only makes sense if the platform has package states with a target residency less than a jiffy. Or, do we enter NOHZ idle? I haven't looked closely enough to figure out yet. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
