On Fri, 31 Oct 2008 16:51:44 -0700 (PDT)
David Miller [off-list ref] wrote:

From: Eric Dumazet <redacted>
Date: Fri, 31 Oct 2008 22:03:00 +0100

quoted

Evgeniy Polyakov a écrit :

quoted

On Fri, Oct 31, 2008 at 12:57:13PM -0700, Stephen Hemminger (shemminger@vyatta.com) wrote:

quoted

Why bother with last_rx at all on loopback.  I have been thinking
we should figure out a way to get rid of last_rx all together. It only
seems to be used by bonding, and the bonding driver could do the calculation
in its receive handling.

Not related to the regression: bug will be just papered out by this
changes. Having bonding on loopback is somewhat strange idea, but still
this kind of changes is an attempt to make a good play in the bad game:
this loopback-only optimization does not fix the problem.

Just to be clear, this change was not meant to be committed.
It already was rejected by David some years ago (2005, and 2006)

http://www.mail-archive.com/netdev@vger.kernel.org/msg07382.html

However, I do like Stephen's suggestion that maybe we can get rid of
this ->last_rx thing by encapsulating the logic completely in the
bonding driver.

Since bonding driver doesn't actually see the rx packets, that isn't
really possible.  But it would be possible to change last_rx from a variable
to an function pointer, so that device's could apply other logic to derive
the last value.  One example would be to keep it per cpu and then take the
maximum.