From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2BD6C4CECD for ; Mon, 16 Sep 2019 13:40:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3C3D214AF for ; Mon, 16 Sep 2019 13:40:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387623AbfIPNkB (ORCPT ); Mon, 16 Sep 2019 09:40:01 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:56886 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732992AbfIPNkB (ORCPT ); Mon, 16 Sep 2019 09:40:01 -0400 Received: from [IPv6:2804:431:c7f4:d32a:d711:794d:1c68:5ed3] (unknown [IPv6:2804:431:c7f4:d32a:d711:794d:1c68:5ed3]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: tonyk) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 1688828D3B4; Mon, 16 Sep 2019 14:39:57 +0100 (BST) Subject: Re: [PATCH v2 4/4] coding-style: add explanation about pr_fmt macro To: Jonathan Corbet Cc: linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, axboe@kernel.dk, kernel@collabora.com, krisman@collabora.com References: <20190913220300.422869-1-andrealmeid@collabora.com> <20190913220300.422869-5-andrealmeid@collabora.com> <20190914015018.4fa90f28@lwn.net> From: =?UTF-8?Q?Andr=c3=a9_Almeida?= Message-ID: Date: Mon, 16 Sep 2019 10:38:50 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.0 MIME-Version: 1.0 In-Reply-To: <20190914015018.4fa90f28@lwn.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/14/19 4:50 AM, Jonathan Corbet wrote: > On Fri, 13 Sep 2019 19:03:00 -0300 > André Almeida wrote: > >> The pr_fmt macro is useful to format log messages printed by pr_XXXX() >> functions. Add text to explain the purpose of it, how to use and an >> example. > > So I've finally had a chance to take a real look at this... > >> diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst >> index f4a2198187f9..1a33a933fbd3 100644 >> --- a/Documentation/process/coding-style.rst >> +++ b/Documentation/process/coding-style.rst >> @@ -819,7 +819,15 @@ which you should use to make sure messages are matched to the right device >> and driver, and are tagged with the right level: dev_err(), dev_warn(), >> dev_info(), and so forth. For messages that aren't associated with a >> particular device, defines pr_notice(), pr_info(), >> -pr_warn(), pr_err(), etc. >> +pr_warn(), pr_err(), etc. It's possible to format pr_XXX() messages using the >> +macro pr_fmt() to prevent rewriting the style of messages. It should be >> +defined before ``#include ``, to avoid compiler warning about >> +redefinitions, or just use ``#undef pr_fmt``. This is particularly useful for >> +adding the name of the module at the beginning of the message, for instance: >> + >> +.. code-block:: c >> + >> + #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > > Honestly, I think that this is out of scope for a document on coding > style. That document is already far too long for most people to read, I > don't think we should load it down with more stuff that isn't directly > style related. > > That said, the information can be useful. I wanted to say that it should > go with the documentation of the pr_* macros but ... well ... um ... we > don't seem to have a whole lot of that. Figures. > > I suspect this is more than you wanted to sign up for, but...IMO, the right > thing to do is to fill printk.h with a nice set of kerneldoc comments > describing how this stuff should be used, then to pull that information > into the core-api manual, somewhere near our extensive discussion of printk > formats. It's amazing that we lack docs for something so basic. > Thanks for the feedback jon. For now, I'll drop this patch for this series. In a future patch I'll move this text for Documentation/core-api/printk-formats.rst and will also add kernel-doc comments to pr_XXXX() functions. > Thanks, > > jon >