From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751839AbaBZI7i (ORCPT ); Wed, 26 Feb 2014 03:59:38 -0500 Received: from merlin.infradead.org ([205.233.59.134]:38371 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751177AbaBZI7h (ORCPT ); Wed, 26 Feb 2014 03:59:37 -0500 Date: Wed, 26 Feb 2014 09:59:26 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: Mathieu Desnoyers , LKML , Ingo Molnar , Rusty Russell , Frederic Weisbecker , Andrew Morton Subject: Re: [RFC][PATCH] tracing: Warn and notify if tracepoints are not loaded due to module taint Message-ID: <20140226085926.GF18404@twins.programming.kicks-ass.net> References: <20140225191505.32b56105@gandalf.local.home> <188130295.30493.1393375141631.JavaMail.zimbra@efficios.com> <20140225194926.4eac5872@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140225194926.4eac5872@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 Tue, Feb 25, 2014 at 07:49:26PM -0500, Steven Rostedt wrote: > > > - if (mod->taints & ~((1 << TAINT_OOT_MODULE) | (1 << TAINT_CRAP))) > > > + if (WARN_ONCE(mod->taints & ~((1 << TAINT_OOT_MODULE) | (1 << TAINT_CRAP)), > > > + "Module is tainted, disabling tracepoints")) > I originally had that with a simple WARN() instead of WARN_ONCE(), but > if you have that config which makes all modules not have sigs correct, > it spits out tens of these warnings and can cause more panic in users > than it deserves. I then switched it to WARN_ONCE(), and then thought, > that if it does it only once for the first module, it wont print the > warning again for the other affected modules. That means it may confuse > the user if they see a module had that warning, but the module they are > trying to trace isn't working either. > > I then figured it would be good to remove the module name and just > state a general "Module is tainted, disabling tracepoints" and if the > user notices that the module isn't working, and then looks at their > dmesg, they'll see this message and just assume it was the module that > wasn't working. > > Make sense? How about instead of a WARN, you use a normal KERN_ERR printk(). There's no point to the entire WARN state dump, that's needlessly verbose. When you have a normal error print you can have as many as are required and put the mod name back in.