Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750942AbXA3S4v (ORCPT ); Tue, 30 Jan 2007 13:56:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750944AbXA3S4v (ORCPT ); Tue, 30 Jan 2007 13:56:51 -0500 Received: from nf-out-0910.google.com ([64.233.182.191]:44849 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750936AbXA3S4u (ORCPT ); Tue, 30 Jan 2007 13:56:50 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=aYW4LALeNJDUThu1MQf3ck+OsfGUOob9x8qUveheUzOWYDswR9LI4aIUUrB8lCfL1SIvDd7ALAl2RtpmRSJms1gxY17zP/bp6kYzEW/2M9iF0Y549hvMxyQCRZAvxemOsMpX3u6YpfiTMZ6+QfdyE/VHujg2IRjAsbc0moU/2n0= Message-ID: <671c20540701301056l6ff1d876xb8df0d9d83ea2c8a@mail.gmail.com> Date: Tue, 30 Jan 2007 13:56:48 -0500 From: "Tom Burns" To: "Tim Schmielau" Subject: Re: Bug: 2.6.15 Process accounting fails to account for small time slice loads (still) Cc: linux-kernel@vger.kernel.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <671c20540701300824p54dad7dbw43fe916bc8c98d45@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1379 Lines: 37 Hi Tim. That would be great if you could find that patch - I can worry about porting it to the current kernel. We're having an issue where our device, while routing large amounts of network traffic, reports 0% CPU utilisation when it cannot be the case, and I think this is the cause. Cheers, Tom Burns On 1/30/07, Tim Schmielau wrote: > On Tue, 30 Jan 2007, Tom Burns wrote: > > > The bug described back in 2004 in the following message still seems to exist: > > > > http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-05/4313.html > > > > Essentially, it appears that if a process sleeps before it uses up a > > complete jiffy then no charge is made to its process accounting table. > > That's not a bug, it's a feature. ;-) > > More seriously, it's a design decision. The benefit of exactly correct > micro bookkeeping does not seem to warrant the extra cost in terms of cpu > cycles spent in the accounting code. > > IIRC there was a patch for that some years ago, if you are interested I > will try to find it. No idea how much work it would be to port it to > current kernels, though. > > Tim > - 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/