From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751291AbWGIQPP (ORCPT ); Sun, 9 Jul 2006 12:15:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751311AbWGIQPP (ORCPT ); Sun, 9 Jul 2006 12:15:15 -0400 Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:44911 "EHLO pd5mo3so.prod.shaw.ca") by vger.kernel.org with ESMTP id S1751291AbWGIQPN (ORCPT ); Sun, 9 Jul 2006 12:15:13 -0400 Date: Sun, 09 Jul 2006 10:11:42 -0600 From: Robert Hancock Subject: Re: Runnable threads on run queue In-reply-to: To: Ask List Cc: linux-kernel@vger.kernel.org Message-id: <44B12ABE.4010303@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: User-Agent: Thunderbird 1.5.0.4 (Windows/20060516) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ask List wrote: > Have an issue maybe someone on this list can help with. > > At times of very high load the number of processes on the run queue drops to > 0 then jumps really high and then drops to 0 and back and forth. It seems to > last 10 seconds or so. If you look at this vmstat you can see an example of > what I mean. Now im not a linux kernel expert but i am thinking it has > something to do with the scheduling algorithm and locking of the run queue. > For this particular application I need all available threads to be processed as > fast as possible. Is there a way for me to elimnate this behavior or at least > minimize the window in which there are no threads on the run queue? Is there a > sysctl parameter I can use? > > Please help. This seems like a userspace issue to me. There is no way the scheduler would let the system sit idle for 10 seconds with runnable processes. I think Rik van Riel's comment about sendmail reacting to increased load average may be related to what's going on here. -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/