From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nivedita Singhvi Subject: Re: [patch 05/13] remove last_rx update from loopback device Date: Tue, 15 Mar 2005 17:23:25 -0800 Message-ID: <42378A8D.7090801@us.ibm.com> References: <200503152222.j2FMMbhG016805@shell0.pdx.osdl.net> <423764A3.8030201@pobox.com> <20050315150809.579c5e85.akpm@osdl.org> <20050315165345.735573de.davem@davemloft.net> <42378617.3080600@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , Andrew Morton , jgarzik@pobox.com, netdev@oss.sgi.com, christoph@graphe.net, nirajk@calsoftinc.com, christoph@lameter.com, Shai@Scalex86.org To: Rick Jones In-Reply-To: <42378617.3080600@hp.com> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Rick Jones wrote: >> These loopback driver SMP optimizations are starting to really >> driver me crazy. > > > Correct or not, I suspect there are a non-trivial number of folks out > there who use loopback performance as an indicator of over the network > performance or at least of stack path length (less driver). I hope not the former. Given that loopback performance is *significantly* faster than network performance, increasing the performance of the loopback driver in these somewhat artificial ways (that differ from the real network device path) simply *increases* the inaccuracy of their testing and the conclusions they can draw from it ;). thanks, Nivedita