Re: Packet time delays on multi-core systems

From: Eric Dumazet
Date: Thu Sep 30 2010 - 14:52:56 EST


Le jeudi 30 septembre 2010 Ã 22:15 +0400, Alexey Vlasov a Ãcrit :
> On Thu, Sep 30, 2010 at 08:03:02PM +0200, Eric Dumazet wrote:
> > >
> > > The last test were made already concerning such rx queue binding:
> > > # cat /proc/irq/60/smp_affinity
> > > 001000
> > > # cat /proc/irq/61/smp_affinity
> > > 010000
> > > # cat /proc/irq/62/smp_affinity
> > > 080000
> > > # cat /proc/irq/63/smp_affinity
> > > 800000
> > >
> >
> > Why 60, 61, 62, 63 ? This should be 753, 754, 755, 756
>
> I've got several similar servers, the interrups 60-63 are on
> that one that I can test now, so this isn't a mistake.
>

If you have a burst of 'LOG' matches, it can really slow down the whole
thing.

You should add a limiter (eg: no more than 5 messages per second)

http://netfilter.org/documentation/HOWTO/packet-filtering-HOWTO-7.html

This module is most useful after a limit match, so you don't
flood your logs.



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