From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751513AbZHKLxb (ORCPT ); Tue, 11 Aug 2009 07:53:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751393AbZHKLxa (ORCPT ); Tue, 11 Aug 2009 07:53:30 -0400 Received: from cam-admin0.cambridge.arm.com ([193.131.176.58]:52330 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751415AbZHKLx2 (ORCPT ); Tue, 11 Aug 2009 07:53:28 -0400 Subject: Re: kmemleak: Protect the seq start/next/stop sequence by rcu_read_lock() From: Catalin Marinas To: Ingo Molnar Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org In-Reply-To: <20090811073205.GA17476@elte.hu> References: <20090729152101.1878.71159.stgit@pc1117.cambridge.arm.com> <20090802111453.GA24927@elte.hu> <1249919718.10848.55.camel@pc1117.cambridge.arm.com> <20090810184527.GA9601@elte.hu> <1249945003.26205.23.camel@pc1117.cambridge.arm.com> <20090811073205.GA17476@elte.hu> Content-Type: text/plain Organization: ARM Ltd Date: Tue, 11 Aug 2009 09:55:05 +0100 Message-Id: <1249980905.27150.11.camel@pc1117.cambridge.arm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 11 Aug 2009 08:55:06.0411 (UTC) FILETIME=[6C4547B0:01CA1A61] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2009-08-11 at 09:32 +0200, Ingo Molnar wrote: > * Catalin Marinas wrote: > > I tried similar config and with the mainline kernel I get some > > lockups (several seconds) with CONFIG_PREEMPT disabled on ARM > > machines or x86 during a scanning episode but it eventually > > completes the scanning. With the kmemleak patches for the next > > merging window, I don't get any lockups as it has more > > cond_resched() calls. > > How big are those patches? Kmemleak is new in .31 so if it fixes a > real problem it might still be acceptable. My patches for -next were posted here - http://lkml.org/lkml/2009/7/24/166 - but the relevant ones are pretty small (review/ack is welcomed): http://lkml.org/lkml/2009/7/24/176 - allow rescheduling during object scanning http://lkml.org/lkml/2009/7/24/173 - inform kmemleak about kernel stack allocation (needs ack by the x86 people) http://lkml.org/lkml/2009/7/24/172 - always scan the task stacks -- Catalin