Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759424AbYCNVUj (ORCPT ); Fri, 14 Mar 2008 17:20:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756399AbYCNVUJ (ORCPT ); Fri, 14 Mar 2008 17:20:09 -0400 Received: from mail.tor.primus.ca ([216.254.136.21]:50327 "EHLO mail-02.primus.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756122AbYCNVUI (ORCPT ); Fri, 14 Mar 2008 17:20:08 -0400 From: Matthew Wilcox To: linux-kernel@vger.kernel.org, sfr@canb.auug.org.au, lenb@kernel.org, dhowells@redhat.com, peterz@infradead.org, mingo@elte.hu, harvey.harrison@gmail.com Cc: Matthew Wilcox , Matthew Wilcox Subject: [PATCH 4/6] Introduce down_killable() Date: Fri, 14 Mar 2008 16:44:51 -0400 Message-Id: <1205527493-5740-4-git-send-email-matthew@wil.cx> X-Mailer: git-send-email 1.5.4.3 In-Reply-To: <1205527493-5740-3-git-send-email-matthew@wil.cx> References: <20080314204248.GV613@parisc-linux.org> <1205527493-5740-1-git-send-email-matthew@wil.cx> <1205527493-5740-2-git-send-email-matthew@wil.cx> <1205527493-5740-3-git-send-email-matthew@wil.cx> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2908 Lines: 87 down_killable() is the functional counterpart of mutex_lock_killable. Signed-off-by: Matthew Wilcox --- include/linux/semaphore.h | 6 ++++++ kernel/semaphore.c | 22 ++++++++++++++++++++++ 2 files changed, 28 insertions(+), 0 deletions(-) diff --git a/include/linux/semaphore.h b/include/linux/semaphore.h index b3c691b..88f2a28 100644 --- a/include/linux/semaphore.h +++ b/include/linux/semaphore.h @@ -62,6 +62,12 @@ extern void down(struct semaphore *sem); extern int __must_check down_interruptible(struct semaphore *sem); /* + * As down_interruptible(), except the sleep may only be interrupted by + * signals which are fatal to this process. + */ +extern int __must_check down_killable(struct semaphore *sem); + +/* * As down(), except this function will not sleep. It will return 0 if it * acquired the semaphore and 1 if the semaphore was contended. This * function may be called from any context, including interrupt and softirq. diff --git a/kernel/semaphore.c b/kernel/semaphore.c index d5a7270..2da2aed 100644 --- a/kernel/semaphore.c +++ b/kernel/semaphore.c @@ -34,6 +34,7 @@ static noinline void __down(struct semaphore *sem); static noinline int __down_interruptible(struct semaphore *sem); +static noinline int __down_killable(struct semaphore *sem); static noinline void __up(struct semaphore *sem); void down(struct semaphore *sem) @@ -61,6 +62,20 @@ int down_interruptible(struct semaphore *sem) } EXPORT_SYMBOL(down_interruptible); +int down_killable(struct semaphore *sem) +{ + unsigned long flags; + int result = 0; + + spin_lock_irqsave(&sem->lock, flags); + if (unlikely(sem->count-- <= 0)) + result = __down_killable(sem); + spin_unlock_irqrestore(&sem->lock, flags); + + return result; +} +EXPORT_SYMBOL(down_killable); + /** * down_trylock - try to acquire the semaphore, without waiting * @sem: the semaphore to be acquired @@ -143,6 +158,8 @@ static inline int __sched __down_common(struct semaphore *sem, long state) for (;;) { if (state == TASK_INTERRUPTIBLE && signal_pending(task)) goto interrupted; + if (state == TASK_KILLABLE && fatal_signal_pending(task)) + goto interrupted; __set_task_state(task, state); spin_unlock_irq(&sem->lock); schedule(); @@ -178,6 +195,11 @@ static noinline int __sched __down_interruptible(struct semaphore *sem) return __down_common(sem, TASK_INTERRUPTIBLE); } +static noinline int __sched __down_killable(struct semaphore *sem) +{ + return __down_common(sem, TASK_KILLABLE); +} + static noinline void __sched __up(struct semaphore *sem) { if (unlikely(list_empty(&sem->wait_list))) -- 1.5.4.3 -- 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/