From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: Info: NAPI performance at "low" loads Date: Tue, 17 Sep 2002 19:16:25 -0700 Sender: netdev-bounce@oss.sgi.com Message-ID: <3D87E1F9.33909AC8@digeo.com> References: <20020917.180014.07882539.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: hadi@cyberus.ca, manfred@colorfullife.com, netdev@oss.sgi.com, linux-kernel@vger.kernel.org Return-path: To: "David S. Miller" Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org "David S. Miller" wrote: > > From: jamal > Date: Tue, 17 Sep 2002 20:57:58 -0400 (EDT) > > I am not so sure with that 6% difference there is no other bug lurking > there; 6% seems too large for an extra two PCI transactions per packet. > > {in,out}{b,w,l}() operations have a fixed timing, therefore his > results doesn't sound that far off. > > It is also one of the reasons I suspect Andrew saw such bad results > with 3c59x, but probably that is not the only reason. They weren't "very bad", iirc. Maybe a 5% increase in CPU load. It was all a long time ago. Will retest if someone sends URLs.