Re: Network performance degradation from 2.6.11.12 to 2.6.16.20

From: Vladimir B. Savkin
Date: Mon Sep 18 2006 - 18:03:52 EST


On Tue, Sep 19, 2006 at 02:00:38AM +0400, Alexey Kuznetsov wrote:
> Hello!
>
> > Please think about it this way:
> > suppose you haave a heavily loaded router and some network problem is to
> > be diagnosed. You run tcpdump and suddenly router becomes overloaded (by
> > switching to timestamp-it-all mode
>
> I am sorry. I cannot think that way. :-)
>
> Instead of attempts to scare, better resend original report,
> where you said how much performance degraded, I cannot find it.
>
> * I do see get_offset_pmtmr() in top lines of profile. That's scary enough.

I had it at the very top line.

> * I do not undestand what the hell dhcp needs timestamps for.
> * I do not listen any suggestions to screw up tcpdump with a sysctl.
> Kernel already implements much better thing then a sysctl.
> Do not want timestamps? Fix tcpdump, add an options, submit the
> patch to tcpdump maintainers. Not a big deal.

OK, point taken.
It's better to patch tcpdump.

>
> Alexey
>
~
:wq
With best regards,
Vladimir Savkin.

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