From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ww0-f49.google.com ([74.125.82.49]) by canuck.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1Q4qXp-0003zd-Be for linux-mtd@lists.infradead.org; Wed, 30 Mar 2011 08:14:26 +0000 Received: by wwb39 with SMTP id 39so831208wwb.18 for ; Wed, 30 Mar 2011 01:14:23 -0700 (PDT) Subject: Re: [PATCH v2] ubifs: fix kconfig dependency warning From: Artem Bityutskiy To: Randy Dunlap In-Reply-To: <20110329084855.0de29fff.randy.dunlap@oracle.com> References: <20110328134016.deb5d0c8.randy.dunlap@oracle.com> <1301382178.2816.69.camel@localhost> <4D91F432.2070406@oracle.com> <1301411055.21445.13.camel@localhost> <20110329084855.0de29fff.randy.dunlap@oracle.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 30 Mar 2011 11:12:09 +0300 Message-ID: <1301472729.2755.19.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-mtd@lists.infradead.org, lkml , Adrian Hunter Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2011-03-29 at 08:48 -0700, Randy Dunlap wrote: > On Tue, 29 Mar 2011 18:04:15 +0300 Artem Bityutskiy wrote: > > > On Tue, 2011-03-29 at 08:01 -0700, Randy Dunlap wrote: > > > On 03/29/11 00:02, Artem Bityutskiy wrote: > > > > On Mon, 2011-03-28 at 13:40 -0700, Randy Dunlap wrote: > > > >> From: Randy Dunlap > > > >> > > > >> Fix another kconfig dependency warning, this time in ubifs. > > > >> > > > >> warning: (UBIFS_FS_DEBUG && LOCKDEP && LATENCYTOP) selects KALLSYMS_ALL which has unmet direct dependencies (DEBUG_KERNEL && KALLSYMS) > > > >> > > > >> Without this patch, we can have: > > > >> # CONFIG_KALLSYMS is not set > > > >> CONFIG_KALLSYMS_ALL=y > > > >> which is useless (does nothing unless KALLSYMS is enabled). > > > >> > > > >> However, ubifs builds successfully with or without this patch, > > > >> and it builds with this line completely deleted, > > > >> so what was this 'select' for? Just developer convenience? > > > > > > > > Well, here is the idea. You can compile UBIFS with debugging and without > > > > debugging. Without debugging the resulting ubifs.ko is much smaller, so > > > > some embedded people prefer it this way. > > > > > > > > If you select debugging support, then we'll compile it a lot of > > > > assertions, self-checks, test-modes, extra error messages with detailed > > > > dumps. And we want to see stackdumps when errors or problems happen, > > > > this is why we select KALLSYMS_ALL. > > > > > > > > So I guess instead we should do: > > > > > > > > select KALLSYMS > > > > select KALLSYMS_ALL > > > > > > Yes, that should do it. Thanks for the explanation. > > > > Will you submit a patch? Alternatively, I can make it myself. What is > > your preference? > > Here's an updated patch. But since KALLSYMS_ALL depends on DEBUG_KERNEL, > the lines above aren't quite sufficient and I don't care to select > DEBUG_KERNEL. What is the real difference between KALLSYMS_ALL and KALLSYMS? It looks like for stack dumps KALLSYMS is enough. The Kconfig help text is not very helpful. And when I look at the help text of CONFIG_KALLSYMS_EXTRA_PASS I get feeling that this area needs some clean-up work. Anyway, any idea why we wouldn't just kill KALLSYMS_ALL by merging it with KALLSYMS? -- Best Regards, Artem Bityutskiy (Артём Битюцкий)