From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758852AbaCTOGi (ORCPT ); Thu, 20 Mar 2014 10:06:38 -0400 Received: from qmta03.emeryville.ca.mail.comcast.net ([76.96.30.32]:42484 "EHLO qmta03.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750960AbaCTOGh (ORCPT ); Thu, 20 Mar 2014 10:06:37 -0400 Date: Thu, 20 Mar 2014 09:06:34 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@nuc To: Andrew Morton cc: Grygorii Strashko , linux-arm , Tejun Heo , linux-kernel@vger.kernel.org, Santosh Shilimkar , Ingo Molnar Subject: Re: [linux-next][regression] [PATCH] percpu: add preemption checks to __this_cpu ops In-Reply-To: <20140318143759.04a892434d84a9fd3aa94262@linux-foundation.org> Message-ID: References: <53285FE7.5010203@ti.com> <53286ABF.3040408@ti.com> <20140318143759.04a892434d84a9fd3aa94262@linux-foundation.org> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 18 Mar 2014, Andrew Morton wrote: > > snprintf can cause hangs. > > This is weird. How the heck can snprintf() fail if called too early? > All it does is shuffle chars around in memory. The only external > dependency I'm seeing is a WARN_ON() which presumably didn't trigger > anyway. > > I'm suspecting a misdiagnosis here. Otherwise, we seriously need to > fix snprintf(), not work around it! > > Also, what does "before checking error conditions" refer to? Does this > mean you know why snprintf() failed?? No I dont. I only know that this fixes Grygorii's issues. There could be numerous arch specific per cpu setup issues going on that may impact on snprintf. If I move it behind the checks then I can avoid using snprintf.