Messages in this thread Patch in this message | | | Subject | Re: [.32-rc3] scheduler: iwlagn consistently high in "waiting for CPU" | From | Mike Galbraith <> | Date | Thu, 08 Oct 2009 16:54:54 +0200 |
| |
On Thu, 2009-10-08 at 16:13 +0200, Mike Galbraith wrote: > On Thu, 2009-10-08 at 06:40 -0700, Arjan van de Ven wrote: > > On Thu, 08 Oct 2009 06:05:43 +0200 > > Mike Galbraith <efault@gmx.de> wrote: > > > > OK, I see latencytop spikes here on an idle box too, to the tune of up > > > to a _second_. Booting with nohz=off seems to have cured it. > > > > interesting.. > > > > > > by chance, does this patch fix it ? > > I haven't seen incredible yet, but with idle box, have seen > 200ms, so > would say no.
But this dinky hunk of my patchlet does indeed still fix it right up.
Index: linux-2.6/kernel/sched_fair.c =================================================================== --- linux-2.6.orig/kernel/sched_fair.c +++ linux-2.6/kernel/sched_fair.c @@ -495,8 +495,10 @@ static void update_curr(struct cfs_rq *c u64 now = rq_of(cfs_rq)->clock; unsigned long delta_exec; - if (unlikely(!curr)) + if (unlikely(!curr)) { + update_rq_clock(rq_of(cfs_rq)); return; + } /* * Get the amount of time the current task was running We have a clock problem with NO_HZ coming out of idle, so we may well have real latency issues at the same time, not bogons.
-Mike
| |