From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 17 May 2002 10:02:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 17 May 2002 10:02:45 -0400 Received: from pizda.ninka.net ([216.101.162.242]:61340 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Fri, 17 May 2002 10:02:43 -0400 Date: Fri, 17 May 2002 06:49:21 -0700 (PDT) Message-Id: <20020517.064921.80183164.davem@redhat.com> To: dipankar@in.ibm.com Cc: linux-kernel@vger.kernel.org Subject: Re: 16-CPU #s for lockfree rtcache (rt_rcu) From: "David S. Miller" In-Reply-To: <20020517192116.G12631@in.ibm.com> X-Mailer: Mew version 2.1 on Emacs 21.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Dipankar Sarma Date: Fri, 17 May 2002 19:21:16 +0530 2.5.3 : ip_route_output_key [c01bab8c]: 12166 2.5.3+rt_rcu : ip_route_output_key [c01bb084]: 6027 Thanks for doing the testing. Are you able to do this test on some 4 or 8 processor non-NUMA system? Basically halfing the profile hits for this function is wonderful and I'd love to see how much of this translates to a non-NUMA system. I have seen moderately significant profile counts for ip_route_input() in preliminary webserver benchmark runs. It is not however clear to me that bucket lock cache line bouncing is the reason behind it. That one needs more investigation. This is where most of the routing heavy work is done on a web server, so this doesn't surprise me. Once packet is input and routed, we have destination and just grab a reference to and use it for output back to that remote host.