Messages in this thread | | | Date | Wed, 11 Dec 2013 09:25:56 +0800 | From | Alex Shi <> | Subject | Re: [question] sched: idle_avg and migration latency |
| |
On 12/11/2013 02:31 AM, Daniel Lezcano wrote: >> >> That has changed a little recently. I originally slammed avg_idle >> itself straight to max to ensure that a bursty load would idle balance, >> and not use stale data. If you start cross core switching at high >> frequency, you'll still shut idle balancing quickly. > > Ok, thanks for the explanation. > > I think I am a bit puzzled with the 'idle_avg' name. I am guessing the > semantic of this variable is "how long this cpu has been idle". > > The idle duration, with the no_hz, could be long, several seconds if the > work queues have been migrated and if the timer affinity is set to > another cpu. So if we fall in this case and there is a burst of activity > + micro-idle and idle_avg is not leverage to max, it will stay high > during an amount of time, thus pulling tasks at each micro idle period, > right ?
yes, I think so.
-- Thanks Alex
| |