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 09:48:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 17 May 2002 09:48:01 -0400 Received: from e21.nc.us.ibm.com ([32.97.136.227]:61639 "EHLO e21.nc.us.ibm.com") by vger.kernel.org with ESMTP id ; Fri, 17 May 2002 09:48:00 -0400 Date: Fri, 17 May 2002 19:21:16 +0530 From: Dipankar Sarma To: linux-kernel@vger.kernel.org Cc: davem@redhat.com Subject: 16-CPU #s for lockfree rtcache (rt_rcu) Message-ID: <20020517192116.G12631@in.ibm.com> Reply-To: dipankar@in.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org As promised, here is the kernprof data from the simulated test suggested by Dave. The test uses 32 processes and dest addresses for rtcache lookup are random, changing after every 5 packets. The measurements were done in a 16 CPU NUMA-Q. 2.5.3 : ip_route_output_key [c01bab8c]: 12166 2.5.3+rt_rcu : ip_route_output_key [c01bb084]: 6027 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. Thanks -- Dipankar Sarma http://lse.sourceforge.net Linux Technology Center, IBM Software Lab, Bangalore, India.