Messages in this thread | | | Date | Thu, 08 May 2014 13:47:29 -0500 | From | Corey Minyard <> | Subject | Re: [PATCH] sched: Initialize rq->age_stamp on processor start |
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On 05/08/2014 11:13 AM, Peter Zijlstra wrote: > On Tue, May 06, 2014 at 02:50:57PM -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> > This patch made my cris-defconfig build fail. Dang, I missed propagating a change. Yes, it's broken. One more time...
-corey
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