From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757636AbYCYU3o (ORCPT ); Tue, 25 Mar 2008 16:29:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753013AbYCYU3g (ORCPT ); Tue, 25 Mar 2008 16:29:36 -0400 Received: from wx-out-0506.google.com ([66.249.82.224]:44453 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752644AbYCYU3f (ORCPT ); Tue, 25 Mar 2008 16:29:35 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=fA29xQqLTNBPZhgQUbgcwKEDFlLWmmmF1ATLb51xyBrOm2WIbFpT2qzCH1HuEdMulgIT7Je8a64xp351G3cvOTMU8n+r713AbSLhgGzDOZs9/ApL1YxAbhT53mpGv/SW2RD3PB4IfyNkZigyrQ84CoSAqWmMEtx1ijNrGxpZg7Y= Message-ID: <998d0e4a0803251329o4dabd28ck5197838fe6920441@mail.gmail.com> Date: Tue, 25 Mar 2008 21:29:34 +0100 From: "J.C. Pizarro" To: LKML Subject: Poor performance now? Please, put weighted velocities ctxts/s to the sched.decision! MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [1] "Performance changes between 2.6.13 and 2.6.23" http://lkml.org/lkml/2008/3/25/102 On Tue, Mar 25, 2008 at 1:34 PM, Sanders, Rob M. wrote: > Of more particular concern, the main application that I build has seen a 4-5X > slowdown in performance. Under YDL4.0.91 I could process roughly 1e8 data > points in ~2 seconds, and under YDL6.0 I now process 1e8 data points in > ~8 seconds. Total CPU loading (from top) is about 5%, under both systems. ... > YDL4.0.91 system is context switching about 7000 per interval, whereas the > YDl6 system is context switching about 1200 times per interval. It's the velocity, ctxts/interval, a parameter not recognized by the scheduler. I said them to put the proposal of putting the counters and velocities fields to the task's struct for the scheduler can take a good decision, the past month. More weight in higher ctxts/s for the scheduler=> more interactivity. [2] "Re: Serious performance regression in Wine applications and Linux 2.6.24.*" http://lkml.org/lkml/2008/3/25/181 On Tue, 25 Mar 2008 08:49:13 -0700, "Ray Lee" wrote: > Andi's idea of looking for excessive context switches is good -- I > didn't see a response to that one. Other than that, if you're only > noticing the issue in 3d games, then it could be several things (not > just the scheduler). The kernel needed the velocity parameter to gain it: ctxts per interval (normally ctxts/s or ctxts/minute). The proposal of the past month was here: "Please, put 64-bit counter per task and incr.by.one each ctxt switch." http://lkml.org/lkml/2008/2/23/398 http://lkml.org/lkml/2008/2/23/401 http://lkml.org/lkml/2008/2/23/406 http://lkml.org/lkml/2008/2/24/1 http://lkml.org/lkml/2008/2/24/103 http://lkml.org/lkml/2008/2/24/157 http://lkml.org/lkml/2008/2/26/159 My proposal is free for yours, quasi-bastards, I won't charge you! J.C.Pizarro