Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754406AbXFVGxK (ORCPT ); Fri, 22 Jun 2007 02:53:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751219AbXFVGw6 (ORCPT ); Fri, 22 Jun 2007 02:52:58 -0400 Received: from mx10.go2.pl ([193.17.41.74]:47172 "EHLO poczta.o2.pl" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750769AbXFVGw5 (ORCPT ); Fri, 22 Jun 2007 02:52:57 -0400 Date: Fri, 22 Jun 2007 09:00:56 +0200 From: Jarek Poplawski To: Ingo Molnar Cc: Linus Torvalds , Eric Dumazet , Chuck Ebbert , Miklos Szeredi , chris@atlee.ca, linux-kernel@vger.kernel.org, tglx@linutronix.de, akpm@linux-foundation.org Subject: Re: [patch] spinlock debug: make looping nicer Message-ID: <20070622070056.GA1778@ff.dom.local> References: <467AAB04.2070409@redhat.com> <20070621202917.a2bfbfc7.dada1@cosmosbay.com> <20070621200941.GB22303@elte.hu> <20070621204234.GA1510@elte.hu> <20070621211525.GA9973@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070621211525.GA9973@elte.hu> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1295 Lines: 32 On Thu, Jun 21, 2007 at 11:15:25PM +0200, Ingo Molnar wrote: > > * Linus Torvalds wrote: > > > On Thu, 21 Jun 2007, Ingo Molnar wrote: > > > > > > btw., back then we also tried a spin_is_locked() based inner loop > > > but it didnt help the ->tree_lock lockups either. In any case i very > > > much agree that the 'nicer' looping should be added again - the > > > patch below does that. (build and boot tested) > > > > Ok, I'm definitely not going to apply it right now, though. > > yeah, very much so. Lots of distros ship with spinlock debugging enabled > (at least in their betas), we dont want to break that accidentally. But, I hope, Miklos will manage to find some time to try this patch or spinlock debugging on, to confirm the nature isn't mocking us here... Miklos, I'd appreciate it very much if you could also exclude my another extremely silly suspicion, and try with only cpu_relax() instead of yield() (but without removing if (preempted)) in wait_task_inactive(). Thanks & regards, Jarek P. - 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/