From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755868Ab0FYNEx (ORCPT ); Fri, 25 Jun 2010 09:04:53 -0400 Received: from ozlabs.org ([203.10.76.45]:38768 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754214Ab0FYNEv (ORCPT ); Fri, 25 Jun 2010 09:04:51 -0400 To: Ingo Molnar From: Rusty Russell Message-Id: <201006252234.46031.rusty@rustcorp.com.au> Date: Fri, 25 Jun 2010 22:34:45 +0930 Subject: [PATCH 4/5] cpumask: remove struct cpumask definition when CONFIG_CPUMASK_OFFSTACK=y Cc: linux-kernel@vger.kernel.org, Arnd Bergmann , anton@samba.org, KOSAKI Motohiro , Mike Travis Cc: anton@samba.org Cc: KOSAKI Motohiro Cc: Mike Travis MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We're about to change CONFIG_CPUMASK_OFFSTACK so it only allocate nr_cpu_ids bits for all cpumasks. We need to make sure that when CONFIG_CPUMASK_OFFSTACK is set: 1) Noone uses the old bitmap ops, which use NR_CPUS bits (use cpumask_*) 2) Noone uses assignment of struct cpumask (use cpumask_copy) 3) Noone passes a struct cpumask (pass a pointer) 4) Noone declares them on the stack (use cpumask_var_t) So we finally remove the definition of struct cpumask when CONFIG_CPUMASK_OFFSTACK=y. This means that these usages will hit a compile error the moment that config option is turned on. Note that it also means you can't declare a static cpumask. You should avoid this anyway (use cpumask_var_t), but there's a deliberately-ugly workaround for special cases, using DECLARE_BITMAP() and to_cpumask(). Signed-off-by: Rusty Russell Cc: Arnd Bergmann Cc: anton@samba.org Cc: KOSAKI Motohiro Cc: Mike Travis --- include/linux/cpumask.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -10,7 +10,15 @@ #include #include +#ifdef CONFIG_CPUMASK_OFFSTACK +/* + * This is never declared, so you can't accidentally create one (see + * cpumask_var_t) or copy them by assignment (see cpumask_copy). + */ +struct cpumask; +#else typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t; +#endif /* CONFIG_CPUMASK_OFFSTACK */ /** * cpumask_bits - get the bits in a cpumask @@ -19,7 +28,14 @@ typedef struct cpumask { DECLARE_BITMAP( * You should only assume nr_cpu_ids bits of this mask are valid. This is * a macro so it's const-correct. */ +#ifdef CONFIG_CPUMASK_OFFSTACK +static inline unsigned long *cpumask_bits(const struct cpumask *mask) +{ + return (unsigned long *)mask; +} +#else #define cpumask_bits(maskp) ((maskp)->bits) +#endif #if NR_CPUS == 1 #define nr_cpu_ids 1