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* Frans Pop <elendil@planet.nl> wrote: > > It would be nice if you could try sched-devel/latest because it has > > an improved ftrace "sched_switch" tracer where you can generate much > > longer traces of this incident. Try the new /debug/trace_entries > > runtime tunable. > > I'll try to get the trace and will reply on the private thread we had. > I may need additional instructions though. you could also reply to this thread if you dont mind, so that others can chime in too. the 700-800 msecs of delays you see are very "brutal" so there must be something fundamentally wrong going on here. Could you first check (under sched-devel/latest) the quality of your sched-clock, via running this script: http://people.redhat.com/mingo/cfs-scheduler/tools/watch-rq-clock.sh if you run it, it should output ~1000 msecs periods every second: europe:~> watch-rq-clock.sh 1002.115042 1005.509851 1004.187275 1004.409980 1004.430264 1004.445508 if it's way too 'slow', say it only 100 msecs per second, then the scheduler clock is mis-measuring time and what the scheduler thinks to be a 40 msecs delay might become a 400 msecs delay. Ingo | ||||||||||
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