Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754804Ab2BFBZE (ORCPT ); Sun, 5 Feb 2012 20:25:04 -0500 Received: from mail-qy0-f174.google.com ([209.85.216.174]:57512 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754674Ab2BFBZD convert rfc822-to-8bit (ORCPT ); Sun, 5 Feb 2012 20:25:03 -0500 MIME-Version: 1.0 In-Reply-To: References: <4F2EED22.3070901@t-online.de> Date: Mon, 6 Feb 2012 09:25:01 +0800 X-Google-Sender-Auth: Q_l69mszp885eZrfA7yeIXxm6gE Message-ID: Subject: Re: [BUG 3.3-rc2] spinlock trylock failure on UP on CPU#0 From: Shaohua Li To: Linus Torvalds Cc: Knut Petersen , Jens Axboe , Tejun Heo , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1245 Lines: 27 2012/2/6 Linus Torvalds : > Ok, interesting. You're triggering the issue because you have a UP > build with the spinlock debugging code enabled. > > On Sun, Feb 5, 2012 at 12:57 PM, Knut Petersen > wrote: >> Booting ?23783f817bceedd6d4e549385e3f400ea64059e5 I get the following trace >> an AOpen i915GMm-hfs with Pentium-M Dothan: > > This is probably the same "technically legal" code that LOCKDEP also > is unhappy about - the nested fast path release. We do a trylock on > the queue lock while we already are holding the queue lock > recursively. > > Jens, Tejun - the crazy-ass games that this code is playing is clearly > messing not just with lockdep, it's messing with some very reasonable > spinlock sanity checks on UP (which just boil down to "a spinlock > should never have contention on UP") > > Any chance of sanitizing this all? I just sent out a debug patch, please try: http://marc.info/?l=linux-kernel&m=132849146702770&w=2 -- 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/