On Thursday 28 August 2008 10:48, David Miller wrote:

From: Nick Piggin <redacted>
Date: Thu, 28 Aug 2008 10:45:03 +1000

quoted

On Thursday 28 August 2008 08:39, Andi Kleen wrote:

quoted

On Wed, Aug 27, 2008 at 03:18:24PM -0700, David Miller wrote:

quoted

From: Andi Kleen <redacted>
Date: Wed, 27 Aug 2008 18:27:35 +0200

quoted

quoted

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).

Would it make sense to make a new option for these socket timestamps
and encourage some apps move over to it?

We don't have support to using these specific hardware provided timestamps
sources yet, so it's kind of premature to recommend the facility to
applications. :)

Dang, that was a really badly quoted. I was reading the thread and
got to the end and just fired off my reply from there...

Sorry -- what I meant to ask was, would it make sense to have a new
option to enable time stamp measuring in the socket receive layer
as in the patchset that Andi referenced, but without removing existing
support for early timestamping?