Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755713Ab0LDTvg (ORCPT ); Sat, 4 Dec 2010 14:51:36 -0500 Received: from fanny.its.uu.se ([130.238.4.241]:59776 "EHLO fanny.its.uu.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755543Ab0LDTvf (ORCPT ); Sat, 4 Dec 2010 14:51:35 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <19706.39875.954626.75344@pilspetsen.it.uu.se> Date: Sat, 4 Dec 2010 20:51:31 +0100 From: Mikael Pettersson To: Mikael Pettersson Cc: "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Maciej Rutecki , Florian Mickler , Venkatesh Pallipadi Subject: Re: [Bug #23902] [BUG] 2.6.37-rc3 massive interactivity regression on ARM In-Reply-To: <19706.13300.115878.641839@pilspetsen.it.uu.se> References: <1OMp3vU_qjP.A.JXG.uxC-MB@chimera> <19706.13300.115878.641839@pilspetsen.it.uu.se> X-Mailer: VM 7.17 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1691 Lines: 39 Mikael Pettersson writes: > Rafael J. Wysocki wrote: > > This message has been generated automatically as a part of a summary report > > of recent regressions. > > > > The following bug entry is on the current list of known regressions > > from 2.6.36. Please verify if it still should be listed and let the tracking team > > know (either way). > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=23902 > > Subject : [BUG] 2.6.37-rc3 massive interactivity regression on ARM > > Submitter : Mikael Pettersson > > Date : 2010-11-27 15:16 (6 days old) > > Message-ID : <19697.8378.717761.236202@pilspetsen.it.uu.se> > > References : http://marc.info/?l=linux-kernel&m=129087098911837&w=2 > > The bug is still present in 2.6.37-rc4. I'm currently trying to bisect it. git bisect identified [305e6835e05513406fa12820e40e4a8ecb63743c] sched: Do not account irq time to current task as the cause of this regression. Reverting it from 2.6.37-rc4 (requires some hackery due to subsequent changes in the same area) restores sane behaviour. (Author of original patch cc:d.) The original patch submission talks about irq-heavy scenarios. My case is the exact opposite: UP, !PREEMPT, NO_HZ, very low irq rate, essentially 100% CPU bound in userspace but expected to schedule quickly when needed (e.g. running top or ps or just hitting CR in one shell while another runs a compile job). /Mikael -- 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/