Messages in this thread | | | Date | Sat, 16 Sep 2006 16:08:46 +0400 | From | "Vladimir B. Savkin" <> | Subject | Re: Network performance degradation from 2.6.11.12 to 2.6.16.20 |
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On Mon, Jun 19, 2006 at 05:24:31PM +0200, Andi Kleen wrote: > > > 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.
I just found out that TSC clocksource is not implemented on x86-64. Kernel version 2.6.18-rc7, is it true?
I've also had experience of unsychronized TSC on dual-core Athlon, but it was cured by idle=poll.
> > > > > 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. > It seems that dhcpd3 makes the box timestamping incoming packets, killing the performance. I think that combining router and DHCP server on a same box is a legitimate situation, isn't it?
~ :wq With best regards, Vladimir Savkin.
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