From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932141AbaEKGCq (ORCPT ); Sun, 11 May 2014 02:02:46 -0400 Received: from ns.horizon.com ([71.41.210.147]:40317 "HELO ns.horizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1757913AbaEKGCp (ORCPT ); Sun, 11 May 2014 02:02:45 -0400 Date: 11 May 2014 02:02:39 -0400 Message-ID: <20140511060239.22063.qmail@ns.horizon.com> From: "George Spelvin" To: linux@horizon.com, tj@kernel.org Subject: Re: [PATCH 1/2] Add lib/glob.c Cc: akpm@linux-foundation.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, torvalds@linux-foundation.org In-Reply-To: <20140510122138.GA4721@mtj.dyndns.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 10 May 2014 08:21:38 -0400, Tejun Heo wrote: > On Fri, May 09, 2014 at 11:13:56PM -0400, George Spelvin wrote: >> +config GLOB >> + tristate >> +# (Prompt disabled to reduce kbuild clutter until someone needs it.) >> +# prompt "glob_match() function" >> + help >> + This option provides a glob_match function for performing simple >> + text pattern matching. It is primarily used by the ATA code >> + to blacklist particular drive models, but other device drivers >> + may need similar functionality. >> + >> + All in-kernel drivers that require this function automatically >> + select this option. Say N unless you are compiling an out-of >> + tree driver which tells you it depend on it. > Just adding glob.o to lib-y should be enough. It will be excluded > from linking if unused. But, I just confirmed, it will also be excluded from linking if CONFIG_ATA=m. See for example commit b4d3ba3346f0 where some helpers had to be moved from lib-y to obj-y to fix module load errors. (Thanks to Randy Dunlap for this example.) >> +#else >> + >> +#include >> +#include >> + >> +MODULE_DESCRIPTION("glob(7) matching"); >> +MODULE_LICENSE("Dual MIT/GPL"); > Do we make library routines separate modules usually? There are basically three options I can see: 1) Make it non-configurable and always include the code in the kernel using oby-y, and just accept the wasted space if CONFIG_ATA=n 2) Make it a boolean option, so CONFIG_ATA=m will force CONFIG_GLOB=y and it will be included in the static kernel but unused until the module is loaded. 3) Make it a tristate option, which compiles into the kernel if CONFIG_ATA=y (the common case), and is its own module if CONFIG_ATA=m. An awful lot of the files in lib/ take this approach. Do you have a preference? Option 3 is the current status. (Revised patch will come when I have the self-test converted.)