Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751300AbWC3Act (ORCPT ); Wed, 29 Mar 2006 19:32:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751301AbWC3Acs (ORCPT ); Wed, 29 Mar 2006 19:32:48 -0500 Received: from mtagate3.uk.ibm.com ([195.212.29.136]:50713 "EHLO mtagate3.uk.ibm.com") by vger.kernel.org with ESMTP id S1751300AbWC3Acr (ORCPT ); Wed, 29 Mar 2006 19:32:47 -0500 Message-ID: <442B271D.10208@watson.ibm.com> Date: Wed, 29 Mar 2006 19:32:29 -0500 From: Shailabh Nagar User-Agent: Debian Thunderbird 1.0.2 (X11/20051002) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrew Morton CC: Greg KH , Arjan van de Ven , Jamal , Andi Kleen , linux-kernel Subject: [Patch 0/8] per-task delay accounting Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3099 Lines: 113 Andrew, Could you please include the following delay accounting patches in -mm ? The patches have gone through several iterations on lkml and numerous comments raised by reviewers have been addressed - several netlink interface comments (Jamal) - block I/O collection method (Arjan) - block I/O delays export through /proc (Andi) - performance issues (Greg) (just addressed, see below) - GPL headers (Arjan) Most of the descriptions of the patches are either in the patch itself or in the documentation patch at the end. Thanks --Shailabh Patch series delayacct-setup.patch delayacct-blkio-swapin.patch delayacct-schedstats.patch genetlink-utils.patch delayacct-genetlink.patch delayacct-virtcpu.patch delayacct-procfs.patch delayacct-doc.patch Results highlights - No statistically significant performance degradation is seen in kernbench, hackbench and large OLTP benchmark when delay accounting is configured. The overheads of configuring delay accounting, without enabling at boot time, are statistically negligible for hackbench and a large OLTP benchmark and negative (i.e. performance improves) in kernbench. - Similar lack of degradation is seen in kernbench and hackbench even when delay accounting is enabled at boot. No data could be collected for the large OLTP benchmark (efforts ongoing). Legend Base Vanilla 2.6.16 kernel without any patches applied +patch Delay accounting configured but not enabled at boot +patch+enable Delay accounting enabled at boot but no stats read Time Elapsed time, averaged over 10 runs Stddev Standard deviation of elapsed times Ovhd % difference of elapsed time with respect to base kernel t-value Used to measure statistical significance of difference of two mean values (in this case mean elapsed time). Low t-values indicate insignificant difference. The t-values here were calculated at 95% confidence interval using the tool at http://www.polarismr.com/education/tools_stat_diff_means.html Hackbench --------- 200 groups, using pipes Elapsed time, in seconds, lower better Ovhd Time Stddev Ovhd significant (t-value) Base 0% 43.483 0.178 na +patch 0.1% 43.517 0.265 No (0.337) +patch+enable 0.3% 43.629 0.167 No (1.892) Kernbench --------- Average of 10 iterations Elapsed time, in seconds, lower better Ovhd Time Stddev Ovhd significant (t-value) Base 0% 196.704 0.459 na +patch -0.5% 195.812 0.477 Yes (4.261) +patch+enable 0.02% 196.752 0.356 No (0.261) Large OLTP benchmark -------------------- An industry standard large database online transaction processing workload was run with delay accounting patches configured ON and OFF. The performance degradation of delay accounting was about 0.2%, which was well within the normal range of variation between similar runs. No runs were taken with delay accounting enabled at boot time. - 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/