Messages in this thread | | | Date | Fri, 9 May 2014 11:12:45 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH] sched: Initialize rq->age_stamp on processor start |
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On Thu, May 08, 2014 at 01:47:39PM -0500, minyard@acm.org wrote: > From: Corey Minyard <cminyard@mvista.com> > > If the sched_clock time starts at a large value, the kernel will spin > in sched_avg_update for a long time while rq->age_stamp catches up > with rq->clock. > > The comment in kernel/sched/clock.c says that there is no strict promise > that it starts at zero. So initialize rq->age_stamp when a cpu starts up > to avoid this. > > I was seeing long delays on a simulator that didn't start the clock at > zero. This might also be an issue on reboots on processors that don't > re-initialize the timer to zero on reset, and when using kexec. > > Signed-off-by: Corey Minyard <cminyard@mvista.com>
Thanks [unhandled content-type:application/pgp-signature] | |