On Wed, Nov 18, 2015 at 12:27:04PM +0000, Morten Rasmussen wrote: > 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.
The code uses hrtimers (badly), this means there _should_ not be a tick dependency. > 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. The idea is to hit NOHZ. -- 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/
