From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761406AbYEGEhr (ORCPT ); Wed, 7 May 2008 00:37:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753329AbYEGEhi (ORCPT ); Wed, 7 May 2008 00:37:38 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:39531 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751904AbYEGEhh (ORCPT ); Wed, 7 May 2008 00:37:37 -0400 Date: Tue, 6 May 2008 21:37:17 -0700 From: Arjan van de Ven To: Andrew Morton Cc: David Miller , tony@bakeyournoodle.com, linux-kernel@vger.kernel.org, benh@kernel.crashing.org Subject: Re: [PATCH] Silence 'ignoring return value' warnings in drivers/video/aty/radeon_base.c Message-ID: <20080506213717.725784ec@infradead.org> In-Reply-To: <20080506212314.695daf98.akpm@linux-foundation.org> References: <20080424043400.GS20457@bakeyournoodle.com> <20080506143936.6357e578.akpm@linux-foundation.org> <20080506.144301.233784820.davem@davemloft.net> <20080506145608.565b61bf.akpm@linux-foundation.org> <20080506210055.75e2f881@infradead.org> <20080506211233.f050fd41.akpm@linux-foundation.org> <20080506211552.6af7cecc@infradead.org> <20080506212314.695daf98.akpm@linux-foundation.org> Organization: Intel X-Mailer: Claws Mail 3.3.1 (GTK+ 2.12.9; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 6 May 2008 21:23:14 -0700 Andrew Morton wrote: > On Tue, 6 May 2008 21:15:52 -0700 Arjan van de Ven > wrote: > > > On Tue, 6 May 2008 21:12:33 -0700 > > > > > > can we make it a WARN_ON() as well? that way we'll see it in > > > > various kerneloops.org stats etc etc.. and we also get a nice > > > > backtrace for free to go with it.... > > > > > > > > (rationale: users tend to not read their dmesg much, but > > > > WARN_ON()'s do get noticed) > > > > > > OK by me, although if we're going to do much more of this it > > > might be time to add a WARN_ON which takes (fmt, args...). > > > > totally; I was just talking to some others about doing just this. > > The challenge will be to minimise the code footprint. the meat of WARN_ON() is already out of line; so all the vararg stuff is just going to be one function out of line, if we really care about the last 20 bytes we can even implement WARN_ON() using an empty string. I suspect it's not all that bad. (but gcc is still churning, so no hard data yet) > otcompletelyoh, perhaps we could generate a backtrace from within > printk() itself for when it sees messages which have KERN_ERR or some > other suitably-chosen (and probably configurable) facility level. interesting thought. Only thing is that this won't give the option to have a condition there, or to compile it out for those folks who care about squeezing the last bytes out by disabling such debug messages. > > That'll generate false positives and will reveal dubious choices, but > we can fix those up. I'm not all that worried about that; if we introduce a new flag that is it'll be explicit and fine.