From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756924Ab0LBDMo (ORCPT ); Wed, 1 Dec 2010 22:12:44 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45850 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756246Ab0LBDMn (ORCPT ); Wed, 1 Dec 2010 22:12:43 -0500 Message-ID: <4CF70FCE.7060606@redhat.com> Date: Thu, 02 Dec 2010 11:17:34 +0800 From: Cong Wang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Shredder/3.0.4 MIME-Version: 1.0 To: Greg KH CC: Greg KH , linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: Re: [Patch] debugfs: remove module_exit() References: <20101109092449.6284.90481.sendpatchset@localhost.localdomain> <20101201013547.GA19390@kroah.com> <4CF5EC28.6060402@redhat.com> <20101201155635.GA29078@suse.de> In-Reply-To: <20101201155635.GA29078@suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/01/10 23:56, Greg KH wrote: > On Wed, Dec 01, 2010 at 02:33:12PM +0800, Cong Wang wrote: >> On 12/01/10 09:35, Greg KH wrote: >>> On Tue, Nov 09, 2010 at 04:19:58AM -0500, Amerigo Wang wrote: >>>> debugfs can't be a module, so module_exit() is meaningless >>>> for it. >>>> >>>> Signed-off-by: WANG Cong >>>> >>>> --- >>>> diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c >>>> index 37a8ca7..d38c88f 100644 >>>> --- a/fs/debugfs/inode.c >>>> +++ b/fs/debugfs/inode.c >>>> @@ -13,9 +13,6 @@ >>>> * >>>> */ >>>> >>>> -/* uncomment to get debug messages from the debug filesystem, ah the irony. */ >>>> -/* #define DEBUG */ >>> >>> Why did you remove these lines? They don't pertain to this patch. >> >> These lines are obsolete. > > Even if they were (and hint, I don't think they are), they have nothing > to do with the patch you created so they don't belong here. The rule is > "one patch per logical change" and you didn't even describe that you > were removing these lines in the changelog entry, so that's two strikes > against removing these lines. > Ok, teach me where DEBUG is used in that file? >>>> - >>>> #include >>>> #include >>>> #include >>>> @@ -540,17 +537,5 @@ static int __init debugfs_init(void) >>>> >>>> return retval; >>>> } >>>> - >>>> -static void __exit debugfs_exit(void) >>>> -{ >>>> - debugfs_registered = false; >>>> - >>>> - simple_release_fs(&debugfs_mount,&debugfs_mount_count); >>>> - unregister_filesystem(&debug_fs_type); >>>> - kobject_put(debug_kobj); >>>> -} >>> >>> When the code is built into the kernel, the __exit function should go >>> away, so this isn't costing us any extra memory, right? >> >> >> Perhaps, but this can still reduce the vmlinux size, right? > > Which really doesn't matter, right? How much is it reduced? > >>> And debugfs used to be able to be built as a module, perhaps it will be >>> in the future? I don't think this patch is really needed. >>> >> >> Huh? Wasn't it a module before? > > Yes it was. > >> I think the problem is tracers use debugfs, it needs to depends on DEBUGFS=y. > > So if you disable tracing, then you could use debugfs as a module, > right? So the patch should not be applied. > No, that CONFIG is a bool, no way to make it as a module. Since you insist, I will send a patch to make it as a module. Thanks.