Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751468AbbEYRo2 (ORCPT ); Mon, 25 May 2015 13:44:28 -0400 Received: from relay.parallels.com ([195.214.232.42]:43909 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750969AbbEYRoZ (ORCPT ); Mon, 25 May 2015 13:44:25 -0400 Message-ID: <1432575859.6866.34.camel@odin.com> Subject: [PATCH RFC 02/13] rwlock_t: Implement double_write_{,un}lock() From: Kirill Tkhai To: CC: Oleg Nesterov , Andrew Morton , Ingo Molnar , "Peter Zijlstra" , Michal Hocko , "Rik van Riel" , Ionut Alexa , Peter Hurley , Kirill Tkhai Date: Mon, 25 May 2015 20:44:19 +0300 In-Reply-To: <20150525162722.5171.15901.stgit@pro> References: <20150525162722.5171.15901.stgit@pro> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.9-1+b1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.30.16.109] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1223 Lines: 43 New helpers for locking two locks at a time. Signed-off-by: Kirill Tkhai --- include/linux/spinlock.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 3e18379..e1e3054 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -426,4 +426,23 @@ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); #define atomic_dec_and_lock(atomic, lock) \ __cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) +static inline void double_write_lock(rwlock_t *lock1, rwlock_t *lock2) +{ + if (lock1 < lock2) { + write_lock(lock1); + write_lock(lock2); + } else if (lock1 > lock2) { + write_lock(lock2); + write_lock(lock1); + } else { + write_lock(lock1); + } +} +static inline void double_write_unlock(rwlock_t *lock1, rwlock_t *lock2) +{ + if (lock2 != lock1) + write_unlock(lock2); + write_unlock(lock1); +} + #endif /* __LINUX_SPINLOCK_H */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/