Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 31 Jan 2002 17:21:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 31 Jan 2002 17:21:29 -0500 Received: from e21.nc.us.ibm.com ([32.97.136.227]:11939 "EHLO e21.nc.us.ibm.com") by vger.kernel.org with ESMTP id ; Thu, 31 Jan 2002 17:21:21 -0500 Importance: Normal Sensitivity: Subject: Test results of context-switch under O(1) J9 scheduler To: lse-tech@lists.sourceforge.net, linux-kernel@vger.kernel.org Cc: "ltc performance" X-Mailer: Lotus Notes Release 5.0.3 (Intl) 21 March 2000 Message-ID: From: "Duc Vianney" Date: Thu, 31 Jan 2002 16:21:18 -0600 X-MIMETrack: Serialize by Router on D04NM201/04/M/IBM(Release 5.0.9 |November 16, 2001) at 01/31/2002 05:21:20 PM MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org The O(1) J9 scheduler with changes to generic context-switch definitely provides the best context-switch latency time based on the lat_ctx test from LMBench benchmark. Test hardware was a 2-way SMP system with 512MB memory. The results obtained from a 2.4.17 SMP kernel built with O(1)J2, O(1)J4 and O(1)J9 versions, compared against 2.2.19 base and 2.4.17 base. The data are time in microsecs. In almost all test cases, context switches under O(1)J9 seem much faster than 2.4.17 base, and as fast as 2.2.19 (or better at heavy load). The 2.2.19 measurements were used as a reference point for 2.2.x. Ratio of Base Base O(1)J2 O(1)J4 O(1)J9 O(1)J9 / Kernel 2.2.19 2.4.17 2.4.17 2.4.17 2.4.17 2417Base lat_ctx -s 0 2 4 8 16 32 64 2 1.46 3.03 7.38 7.38 0.97 32.0% 4 2.04 3.55 4.84 4.89 4.97 140.2% 8 2.74 4.41 6.04 4.96 4.43 100.6% 16 3.01 4.78 4.93 5.46 3.82 80.0% 32 5.48 7.29 4.80 5.75 4.56 62.6% 64 5.74 8.37 5.86 6.12 5.62 67.1% lat_ctx -s 16 2 4 8 16 32 64 2 14.33 16.15 15.62 15.11 13.93 86.3% 4 14.30 16.13 17.83 16.27 16.51 102.4% 8 14.39 16.38 17.58 17.35 15.20 92.8% 16 16.43 19.34 17.75 17.70 16.54 85.6% 32 39.92 39.93 24.63 24.95 32.65 81.8% 64 53.67 49.87 45.34 42.76 49.91 100.1% lat_ctx -s 32 2 4 8 16 32 64 2 22.86 24.73 27.56 27.03 24.29 98.2% 4 22.85 24.85 25.98 25.78 25.22 101.5% 8 25.18 30.94 26.51 26.65 25.04 81.0% 16 58.70 74.32 38.69 35.07 48.32 65.0% 32 99.16 94.41 74.32 74.85 89.62 94.9% 64 99.28 96.91 98.45 97.75 94.29 97.3% lat_ctx -s 64 2 4 8 16 32 64 2 40.24 42.06 44.57 44.11 40.72 96.8% 4 49.10 43.28 43.23 43.99 42.85 99.0% 8 111.28 105.56 49.43 45.81 58.41 55.3% 16 185.12 182.84 127.11 124.74 169.94 92.9% 32 185.20 182.81 184.97 182.92 175.70 96.1% 64 185.26 184.46 186.54 186.22 178.63 96.8% Duc. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/