From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760296AbYGRWP7 (ORCPT ); Fri, 18 Jul 2008 18:15:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760502AbYGRWMr (ORCPT ); Fri, 18 Jul 2008 18:12:47 -0400 Received: from rv-out-0506.google.com ([209.85.198.237]:10982 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760482AbYGRWMp (ORCPT ); Fri, 18 Jul 2008 18:12:45 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=JzyQh/e8ymcq8uqxLKhX4lUl2RLTdLPl+GSBTsdnjtnZSX25hvPLaI3M8BAFILnxGz iaAXDkYeBW5WNVGGFEMLdRWKqn1Ro1/rgqSQQ8Ky1rf3HbIEIiGgI1JfinUdjP87kSmG mizFTBaazPaVTdjVc3rxHymyKEtmUrteV8BRs= Message-ID: <9871ee5f0807181512u231e1aaraee5622d0a814f97@mail.gmail.com> Date: Fri, 18 Jul 2008 18:12:44 -0400 From: "Timothy Normand Miller" To: "Peter Zijlstra" Subject: Re: Problem: Load average of 6, no I/O, 25% idle time. Why? Cc: linux-kernel@vger.kernel.org In-Reply-To: <1216387716.28405.45.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <9871ee5f0807180549l58e849d9ge6e7deee3d0c37fa@mail.gmail.com> <1216387716.28405.45.camel@twins> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 18, 2008 at 9:28 AM, Peter Zijlstra wrote: > On Fri, 2008-07-18 at 08:49 -0400, Timothy Normand Miller wrote: >> I have a four processor box, running three compute loads. The kernel >> I'm running is 2.6.25-gentoo-r5. >> >> One process has four threads, and it's niced to 19. >> Another process has one thread and is niced to -10 >> The last process has one thread and is niced to 0 >> >> One processor is always idle. >> >> If I change either the 0 to a -10 or the -10 to a zero, then all four >> cores are properly utilized. Interesting corollary: If the only thing running is the one nice=19, four-thread process, then there's about 4% idle time. I have to raise the priority to get the idle time to go away. Since when do active processes yield to idle time? Two of my three loads are finished, so when this last one is done, I'll try 2.6.26. Was something like this actively discussed and fixed between 2.6.25 and 2.6.26? Thanks. -- Timothy Normand Miller http://www.cse.ohio-state.edu/~millerti Open Graphics Project