From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [RFC PATCH -next] Fix printk_once build errors due to __read_mostly Date: Wed, 30 Oct 2013 13:48:39 -0700 Message-ID: <20131030134839.8bdf70cc68d1bf0beb1fb63a@linux-foundation.org> References: <1383128301-20231-1-git-send-email-james.hogan@imgtec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48008 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751797Ab3J3Usk (ORCPT ); Wed, 30 Oct 2013 16:48:40 -0400 In-Reply-To: <1383128301-20231-1-git-send-email-james.hogan@imgtec.com> Sender: linux-next-owner@vger.kernel.org List-ID: To: James Hogan Cc: Joe Perches , linux-kernel@vger.kernel.org, linux-next@vger.kernel.org, linux-metag@vger.kernel.org On Wed, 30 Oct 2013 10:18:21 +0000 James Hogan wrote: > Commit 3e39c1ab04ba (printk: mark printk_once test variable > __read_mostly) added __read_mostly to the __print_once bool in the > printk_once() macro, but __read_mostly is defined in > which isn't included from . This results in build errors > like this: > > arch/metag/mm/l2cache.c: In function 'meta_l2c_setup': > arch/metag/mm/l2cache.c:56: error: '__read_mostly' undeclared > > This is fixed by adding an include of from > since I don't think printk_once() users should need to > include for it to work. > > Note that this actually adds a recursive include, since > includes , which includes . The actual > dependencies are all in macros so it doesn't actually seem to result in > any build failures, but it's clearly less than ideal. Yitch. > Signed-off-by: James Hogan > Cc: Joe Perches > Cc: Andrew Morton > Cc: linux-metag@vger.kernel.org > --- > This build failure was caught in today's linux-next. > > I'm not too keen on this due to the recursive include. Is it better to > just workaround the problem by including from the .c > file that fails to build, or should the original patch be removed > instead? Well, these patches make the kernel worse. We should make it better, not worse. One approach would be to add a new printk_once.h, which includes printk.h and cache.h. I can't immediately think of a nice solution so I guess for now I'll drop printk-mark-printk_once-test-variable-__read_mostly.patch.