Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965564AbVKGXGP (ORCPT ); Mon, 7 Nov 2005 18:06:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965586AbVKGXGP (ORCPT ); Mon, 7 Nov 2005 18:06:15 -0500 Received: from e4.ny.us.ibm.com ([32.97.182.144]:20895 "EHLO e4.ny.us.ibm.com") by vger.kernel.org with ESMTP id S965564AbVKGXGN (ORCPT ); Mon, 7 Nov 2005 18:06:13 -0500 Message-ID: <436FDDE2.4000708@us.ibm.com> Date: Mon, 07 Nov 2005 17:06:10 -0600 From: Brian Twichell User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923) X-Accept-Language: en-us, en MIME-Version: 1.0 To: David Lang CC: linux-kernel@vger.kernel.org, mbligh@mbligh.org, slpratt@us.ibm.com, anton@samba.org Subject: Re: Database regression due to scheduler changes ? References: <436FD291.2060301@us.ibm.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 828 Lines: 24 David Lang wrote: > If I am understanding the data you posted, it looks like you are > useing sched_yield extensivly in your database. Yes, I've seen problems in the past with workloads that use sched_yield heavily. But bear in mind, the ~2700 sched_yields shown in the schedstats occurred over a 9 minute period. That means that sched_yield is being called at a rate of around 5 per second -- this is not a heavy user of sched_yield. To put this into a broader perspective, this workload has around 270 tasks, and the context switch rate is around 45,000 per second. - 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/