From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751629Ab3FQScS (ORCPT ); Mon, 17 Jun 2013 14:32:18 -0400 Received: from merlin.infradead.org ([205.233.59.134]:52418 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090Ab3FQScR (ORCPT ); Mon, 17 Jun 2013 14:32:17 -0400 Date: Mon, 17 Jun 2013 20:32:06 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: LKML , Thomas Gleixner , Frederic Weisbecker , Ingo Molnar , "H. Peter Anvin" , Andrew Morton Subject: Re: [RFC][PATCH] tracing: Disable tracing on warning Message-ID: <20130617183206.GB3204@twins.programming.kicks-ass.net> References: <1371487375.18733.18.camel@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1371487375.18733.18.camel@gandalf.local.home> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 17, 2013 at 12:42:55PM -0400, Steven Rostedt wrote: > Add a traceoff_on_warning option in both the kernel command line as well > as a sysctl option. When set, any WARN*() function that is hit will cause > the tracing_on variable to be cleared, which disables writing to the > ring buffer. > > This is useful especially when tracing a bug with function tracing. When > a warning is hit, the print caused by the warning can flood the trace with > the functions that producing the output for the warning. This can make the > resulting trace useless by either hiding where the bug happened, or worse, > by overflowing the buffer and losing the trace of the bug totally. > > Signed-off-by: Steven Rostedt Neat; Acked-by: Peter Zijlstra