Re: Network performance degradation from 2.6.11.12 to 2.6.16.20

From: Andi Kleen
Date: Mon Jun 19 2006 - 11:23:24 EST



> If you use "pmtmr" try to reboot with kernel option "clock=tsc".

That's dangerous advice - when the system choses not to use
TSC it often has a reason.

>
> On my Opteron AMD system i normally can route 400 kpps, but with
> timesource "pmtmr" i could only route around 83 kpps. (I found the timer
> to be the issue by using oprofile).

Unless you're using packet sniffing or any other application
that requests time stamps on a socket then the timer shouldn't
make much difference. Incoming packets are only time stamped
when someone asks for the timestamps.

-Andi
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