From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751484AbcGMWZt (ORCPT ); Wed, 13 Jul 2016 18:25:49 -0400 Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:46575 "EHLO s-opensource.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751433AbcGMWZk (ORCPT ); Wed, 13 Jul 2016 18:25:40 -0400 Message-ID: <5786BFDA.9030703@osg.samsung.com> Date: Wed, 13 Jul 2016 23:25:30 +0100 From: Luis de Bethencourt User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.8.0 MIME-Version: 1.0 To: Andrew Morton CC: linux-kernel@vger.kernel.org, rusty@rustcorp.com.au, hidehiro.kawai.ez@hitachi.com, bp@suse.de, mina86@mina86.com, linux@rasmusvillemoes.dk, joe@perches.com Subject: Re: [RFC PATCH] dynamic_debug: only add header when used References: <1468429793-16917-1-git-send-email-luisbg@osg.samsung.com> <20160713133254.70078c50b1af9edb8b577499@linux-foundation.org> In-Reply-To: <20160713133254.70078c50b1af9edb8b577499@linux-foundation.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/07/16 21:32, Andrew Morton wrote: > On Wed, 13 Jul 2016 18:09:53 +0100 Luis de Bethencourt wrote: > >> kernel.h header doesn't directly use dynamic debug, instead we can include >> it in module.c (which used it via kernel.h). printk.h only uses it if >> CONFIG_DYNAMIC_DEBUG is on, changing the inclusion to only happen in that >> case. >> >> Signed-off-by: Luis de Bethencourt >> --- >> Hi, >> >> While studying the problem that surfaced when adding #include >> in include/linux/string.h to have access to the MAX_SIZE macro [0]. I noticed >> that dynamic_debug.h is included in kernel.h even though it isn't necessary. >> Which in the case of adding kernel.h to string.h would mean a circular >> dependency. >> >> Not entirely sure if there is a reason for this beyond making dynamic debug >> available to module.c. Which is why I am sending this patch as an RFC. > > It would be good if we can do this. > > What is it in kernel.h that requires dynamic_debug.h? I tried your > patch along with > > --- a/kernel/module.c~dynamic_debug-only-add-header-when-used-fix > +++ a/kernel/module.c > @@ -60,7 +60,6 @@ > #include > #include > #include > -#include > #include > #include "module-internal.h" > > and module.o builds OK. > Hi Andrew, Replying to why dynamic_debug.h is needed in module.c, which I didn't explain before since I wanted to double-check. kernel/module.c only needs dynamic_debug.h when CONFIG_DYNAMIC_DEBUG is not set. Which is probably why you could build it in your side. If you deactivate that config you get an error in the two uses of ddebug_remove_module and one for ddebug_dyndbg_module_param_cb(). For example: ------------------------------------------------------ kernel/module.c: In function ‘free_module’: kernel/module.c:2080:2: error: implicit declaration of function ‘ddebug_remove_module’ [-Werror=implicit-function-declaration] ddebug_remove_module(mod->name); ------------------------------------------------------ By the way, since you added my patch in your -mm tree I resent with you listed as Signed-off-by, I hope that is OK. Let me know if it isn't for the future. Thanks :) Luis