From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754919AbaIVVv1 (ORCPT ); Mon, 22 Sep 2014 17:51:27 -0400 Received: from mga11.intel.com ([192.55.52.93]:50666 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753000AbaIVVvZ (ORCPT ); Mon, 22 Sep 2014 17:51:25 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,574,1406617200"; d="asc'?scan'208";a="479276808" From: "Rustad, Mark D" To: Peter Zijlstra CC: "sparse@chrisli.org" , "linux-kernel@vger.kernel.org" , "richard.weinberger@gmail.com" , "linux-sparse@vger.kernel.org" , "mingo@redhat.com" , "Kirsher, Jeffrey T" , "computersforpeace@gmail.com" Subject: Re: [PATCH] sched: Remove nested extern Thread-Topic: [PATCH] sched: Remove nested extern Thread-Index: AQHP1o5n4j/Km9jR6U6Rx5Rq0DoBGpwN93YAgAAIi4CAAAlVgIAADxwAgAAGBoCAAAhHgA== Date: Mon, 22 Sep 2014 21:50:44 +0000 Message-ID: <9C9DCC69-1F75-4241-A022-FFB9B6A11AC5@intel.com> References: <20140922175511.62229.98784.stgit@mdrustad-wks.jf.intel.com> <20140922190128.GA2805@worktop.programming.kicks-ass.net> <20140922200527.GA3128@worktop.programming.kicks-ass.net> <20140922212105.GD3128@worktop.programming.kicks-ass.net> In-Reply-To: <20140922212105.GD3128@worktop.programming.kicks-ass.net> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: yes X-MS-TNEF-Correlator: x-originating-ip: [134.134.176.145] Content-Type: multipart/signed; boundary="Apple-Mail=_18D117C2-F9E5-459C-A416-EC76765E82F7"; protocol="application/pgp-signature"; micalg=pgp-sha1 MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Apple-Mail=_18D117C2-F9E5-459C-A416-EC76765E82F7 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii On Sep 22, 2014, at 2:21 PM, Peter Zijlstra = wrote: > On Mon, Sep 22, 2014 at 08:59:32PM +0000, Rustad, Mark D wrote: >> Because I have found that enabling many warnings helps identify = problems >> in code and it has been my standard practice since about 1999 to do = so. >> The compiler warnings are really just another form of static = analysis, >> and I use it routinely on every compile. Here is how routinely: I = have >> W=3D1 in my environment, W=3D12 is just too painful. I would change = that >> default to W=3D12 if it wasn't insane to do so. >=20 > Many warnings are just plain insane and stupid. They're not helping > anybody. There's a very good reason many are disabled. I'm sure you = can > find some entertaining discussions on the topic if you search the LKML > archives. That is what I used to think. -Wshadow for example. What's the problem? = It is perfectly valid C. Well, I recently sent a patch that changed some function parameters that used the name jiffies, which of course shadowed the well-known global. If a macro were ever called in those functions whose expansion ever tried to access jiffies, well it wouldn't do what was expected. Not a bug now, but a trap for the future. I only found = that because I either resolved or silenced enough warnings to see something = interesting. Over the years I think I have resolved real bugs revealed by probably = nearly every one of the additional warning messages. They do have value, but = that value is typically lost if the norm is a flood of messages. Apple would = not have had their SSL problem if they had had -Wunreachable-code enabled = and noticed the message. --=20 Mark Rustad, Networking Division, Intel Corporation --Apple-Mail=_18D117C2-F9E5-459C-A416-EC76765E82F7 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="signature.asc" Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Comment: GPGTools - http://gpgtools.org iQIcBAEBAgAGBQJUIJm0AAoJEDwO/+eO4+5u1P8QAKfPs62HndTh+iCaza7BwvwH 6grUaidMoTs2DHPAM1/krZGB0s+TVKqvmlp3YL2QN+JX9qFxLmDyuSILQedJ1kO0 1mw/XTrLiS3g9ZFdM70R3yIPOc2FyiidbE4h5tjqw8GSa8MXpXu52Zv7YKpXDeAe R3FV5AzWV6Gcq1NGwtKqG1tx79ebkXclDd5KIPQ4N291S+iv7+VDMH1dN5RpShmJ +d+OieprfIdF+d2vLMQHfrYALyzsmvGzLGDpK6NV7N4V6CHTCNJwagogyM7ZT9kW YQ9KBkZOiWtGseY2pShoFXMmfJjfbwhECkKNWbajMk9gCM9RYeqlkJm8z3QHReZA jtU0WrBtmBqZEA/TDv8/fKK3SyE2FRSx97kw/5CAgiKp5B15/UE9tU0wAxt5Aqnn VpQ9B3EBQY93T9eOA67svqvDpK7BEFXDKeYtl1u3/Gc5PNGT10/Smx3y9utykGZl rbctZVZga3Jr8nVE4Qt4cdmFvWRdwoFAaEjQOuzIpMKcaP2/G2s8YUbE2E6jpQXA vbsXMkHllcmkYq3hQ+4TQG9DsulcVQHUeYv2NK8F9Q6u6NN6992l/ypAJnxfNJ34 O+XA7vMFr/13elkdIdID5dwJeyBcHnsaRJr2fem74PEUv6fFZQYPZhF+dgWPwKVx b8AP1mz0xoTqF0NmjPep =scE2 -----END PGP SIGNATURE----- --Apple-Mail=_18D117C2-F9E5-459C-A416-EC76765E82F7--