From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262603AbTKIP73 (ORCPT ); Sun, 9 Nov 2003 10:59:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262608AbTKIP73 (ORCPT ); Sun, 9 Nov 2003 10:59:29 -0500 Received: from c211-28-147-198.thoms1.vic.optusnet.com.au ([211.28.147.198]:35820 "EHLO mail.kolivas.org") by vger.kernel.org with ESMTP id S262603AbTKIP70 (ORCPT ); Sun, 9 Nov 2003 10:59:26 -0500 From: Con Kolivas To: Davide Libenzi , "Martin J. Bligh" Subject: Re: [PATCH] Fix find busiest queue 2.6.0-test9 Date: Mon, 10 Nov 2003 02:59:18 +1100 User-Agent: KMail/1.5.3 Cc: Nick Piggin , Andrew Morton , Linux Kernel Mailing List , Ingo Molnar References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200311100259.18883.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 10 Nov 2003 02:53, Davide Libenzi wrote: > On Sun, 9 Nov 2003, Martin J. Bligh wrote: > > I ran it on the 16-way - no difference in performance. If the code is > > correct as was before (and I agree, it seems it was), perhaps it's just > > in need of a big fat comment to explain the confusion? ;-) > > Ingo already dropped a fat comment ;) This is the relevant part: > > * We fend off statistical fluctuations in runqueue lengths by > * saving the runqueue length during the previous load-balancing > * operation and using the smaller one the current and saved lengths. Well that was the comment that led me to make that patch. After discussion with mbligh it seems the confusion coming from me seeing ->prev_cpu_load as the load for that runqueue the last time we balanced; whereas it's actually the load of the last runqueue checked during the balancing. Anyway the performance differences are tiny on my testing and non existent on mblighs so forget it. Con