Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933834AbZJMPGK (ORCPT ); Tue, 13 Oct 2009 11:06:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757788AbZJMPGI (ORCPT ); Tue, 13 Oct 2009 11:06:08 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:48249 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752734AbZJMPGH (ORCPT ); Tue, 13 Oct 2009 11:06:07 -0400 Date: Tue, 13 Oct 2009 08:05:07 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Boyan cc: =?ISO-8859-15?Q?Fr=E9d=E9ric_L=2E_W=2E_Meunier?= , "Justin P. Mattock" , Nix , Alan Cox , Paul Fulghum , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Dmitry Torokhov , Ed Tomlinson , OGAWA Hirofumi Subject: Re: [Bug #14388] keyboard under X with 2.6.31 In-Reply-To: <4AD437F9.9020708@yahoo.co.uk> Message-ID: References: <56acieJJ2fF.A.nEB.Hzl0KB@chimera> <87ljjgfcbu.fsf@spindle.srvr.nix> <4AD3F769.5080405@gmail.com> <4AD437F9.9020708@yahoo.co.uk> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1646 Lines: 36 On Tue, 13 Oct 2009, Boyan wrote: > > I've just tested it on top of 2.6.31.3 and it doesn't work. As I've > mentioned in previous email - I usually trigger the problem easily > watching pictures with gthumb - this is combination of cpu intensive > operations and keyboard usage and if it doesn't work it takes me no more > than a minute to trigger the problem. The whole "CPU intensive" thing makes me wonder.. Do you have 'CONFIG_PREEMPT' enabled? Normally, "CPU intensive" does not at all increase the likelihood of any kernel races, but with kernel preemption we may well hit some preemption point and switch away, and make some race window much bigger. So if you do have CONFIG_PREEMPT on, try to turn it off and see if it makes the problem go away. Also, are people seeing this always running SMP kernels, or are there UP kernels out there too (on UP _without_ preemption it is almost impossible to hit 99% of all race conditions, so if anybody is running an UP kernel with no preemption, then I'd be very surprised if it is a kernel issue). But I also still wonder if it might be user-space races, and just the timing differences in the kernel. I don't know the input layer in X well enough, I'm wondering if things like composition engine/window manager could screw up here. Is there some pattern to the X versions (and/or window managers and composition engines)? Linus -- 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/