From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751750AbaHMK5g (ORCPT ); Wed, 13 Aug 2014 06:57:36 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53361 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750803AbaHMK5f (ORCPT ); Wed, 13 Aug 2014 06:57:35 -0400 Date: Wed, 13 Aug 2014 03:56:40 -0700 From: tip-bot for Bart Van Assche Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, davem@davemloft.net, paulmck@linux.vnet.ibm.com, bvanassche@acm.org, akpm@linux-foundation.org, oleg@redhat.com, tglx@linutronix.de, rientjes@google.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, davem@davemloft.net, paulmck@linux.vnet.ibm.com, bvanassche@acm.org, akpm@linux-foundation.org, tglx@linutronix.de, oleg@redhat.com, rientjes@google.com In-Reply-To: <53E4A7F8.1040700@acm.org> References: <53E4A7F8.1040700@acm.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:locking/core] locking/spinlocks: Always evaluate the second argument of spin_lock_nested() Git-Commit-ID: 4999201a59ef555f9105d2bb2459ed895627f7aa X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 4999201a59ef555f9105d2bb2459ed895627f7aa Gitweb: http://git.kernel.org/tip/4999201a59ef555f9105d2bb2459ed895627f7aa Author: Bart Van Assche AuthorDate: Fri, 8 Aug 2014 12:35:36 +0200 Committer: Ingo Molnar CommitDate: Wed, 13 Aug 2014 10:32:38 +0200 locking/spinlocks: Always evaluate the second argument of spin_lock_nested() Evaluating a macro argument only if certain configuration options have been selected is confusing and error-prone. Hence always evaluate the second argument of spin_lock_nested(). An intentional side effect of this patch is that it avoids that the following warning is reported for netif_addr_lock_nested() when building with CONFIG_DEBUG_LOCK_ALLOC=n and with W=1: include/linux/netdevice.h: In function 'netif_addr_lock_nested': include/linux/netdevice.h:2865:6: warning: variable 'subclass' set but not used [-Wunused-but-set-variable] int subclass = SINGLE_DEPTH_NESTING; ^ Signed-off-by: Bart Van Assche Signed-off-by: Peter Zijlstra Cc: David Rientjes Cc: David S. Miller Cc: Andrew Morton Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Paul E. McKenney Link: http://lkml.kernel.org/r/53E4A7F8.1040700@acm.org Signed-off-by: Ingo Molnar --- include/linux/spinlock.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 3f2867f..262ba4e 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -197,7 +197,13 @@ static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ } while (0) #else -# define raw_spin_lock_nested(lock, subclass) _raw_spin_lock(lock) +/* + * Always evaluate the 'subclass' argument to avoid that the compiler + * warns about set-but-not-used variables when building with + * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1. + */ +# define raw_spin_lock_nested(lock, subclass) \ + _raw_spin_lock(((void)(subclass), (lock))) # define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock) #endif