Re: loaded router, excessive getnstimeofday in oprofile

From: Jarek Poplawski
Date: Tue Aug 26 2008 - 06:47:35 EST


On Tue, Aug 26, 2008 at 01:29:53PM +0300, Denys Fedoryshchenko wrote:
> On Tuesday 26 August 2008, Jarek Poplawski wrote:
> >
> > This function is really used in many places, and these profiles are
> > not enough at least to me, but it seems you could have a lot of
> > softirqs (and probably hrtimers) scheduling, so maybe you should try
> > if e.g. disabling hrtimers or changing kernel HZ makes any difference.
> >
> > Jarek P.
> One user is shapers, it is ok for me.

The question is if you really need so exact shaping at a cost of
higher system load.

> I am not sure, but maybe another user is softlockup debug option... and if
> there is a lot of task switches maybe it will cause excessive load of timers
> slow?

Maybe. Anyway, you could try if lower HZ (with longer jiffies) can help
with processing more skbs without rescheduling.

Jarek P.
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