From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 28 May 2002 07:37:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 28 May 2002 07:37:43 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.101]:38052 "EHLO e1.ny.us.ibm.com") by vger.kernel.org with ESMTP id ; Tue, 28 May 2002 07:37:43 -0400 Date: Tue, 28 May 2002 17:11:04 +0530 From: Dipankar Sarma To: Dave Miller Cc: linux-kernel@vger.kernel.org Subject: 8-CPU (SMP) #s for lockfree rtcache Message-ID: <20020528171104.D19734@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 Hi Dave, Here are the SMP numbers that you had asked for. They were measured on an 8-CPU SMP box (PIII Xeon 700 MHz processors, 1MB L2 cache and 6GB RAM). The test was as per your suggestion. rt_rcu is a patch that uses RCU to do lockfree lookup of ipv4 route cache. The basic test sends a fixed number of packets to random destination addresses repeating every dest for 5 packets. We tried two configurations of this test - 8-1-32 where 32 test processes simultaneosly uses 32 different random seeds to generate different dest addreses and 8-4-8 where 8 sets, each consisting 4 processes all of whom use the same random seed generating the same dst addresses, send packets to the dest addresses repeating dest for every 5 packets. With these basic tests, we measured under several other conditions - avoid forced neighbor table garbage collection by increasing the threshold and interval (to 31048576 and 60) and slowing the packet rate by introducing a delay of 2ms between bursts of 5 packets. Here are the results in terms of profile counts in ip_route_output_key() - gc stands for neighbor table garbage collection adjustment and u2000 stands for 2ms packet rate delay. All measurements where done based on 2.5.3 kernel. Test base rtrcu speedup ---- ---- ----- ------- 8-1-32 2358 1655 29.8% 8-1-32-gc 4486 2176 51.4% 8-1-32-u2000 2990 1942 35.0% 8-1-32-u2000-gc 4047 2029 49.8% 8-4-8 2870 1965 31.5% 8-4-8-gc 3389 2083 38.5% 8-4-8-u2000 3459 2373 31.3% 8-4-8-u2000-gc 4686 2603 44.4% Thanks -- Dipankar Sarma http://lse.sourceforge.net Linux Technology Center, IBM Software Lab, Bangalore, India.