Re: loaded router, excessive getnstimeofday in oprofile

Andi Kleen
2008-08-27T22:37:28Z

On Wed, Aug 27, 2008 at 03:18:24PM -0700, David Miller wrote:
> From: Andi Kleen <andi@firstfloor.org>
> Date: Wed, 27 Aug 2008 18:27:35 +0200
>
> > > Those banks really want to crank down on latency - to the point they
> > > start disabling interrupt coalescing. I bet they'd toss anything out
> > > they could to shave another microsecond.
> >
> > This change would actually likely lower their latency.
>
> They want the timestamps, but they want it to match when the packet
> arrived at their system as closely as is reasonably possible.

Then they should use hardware time stamps which are increasingly
available (e.g. current Intel e1000 design has them and I expect
others too).

-Andi