Re: loaded router, excessive getnstimeofday in oprofile

[Rick Jones]

Andi Kleen wrote:
> Evgeniy Polyakov <johnpol@xxxxxxxxxxx> writes:
>
> > Yup, this innocent toys can end up with this such behaviour on modern
> > highly loaded machines.
>
>
> I and also other people had some patches to move the time stamp
> measuring into the socket. This way the time stamping didn't need to
> be enabled on all packets, only on those that actually end up at a
> socket that requires the time stamp.
>
> Unfortunately DaveM didn't like it because some bank wanted
> different semantics, see the discussion in 
> http://thread.gmane.org/gmane.linux.network/91679
>
> Perhaps you can find out which bank it was and send them a bill for
> your CPU time ;-)

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.

rick jones
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/