From: Xiaoming Ni <nixiaoming@huawei.com>
To: <linux-kernel@vger.kernel.org>, <peterz@infradead.org>,
<mingo@redhat.com>, <will@kernel.org>, <longman@redhat.com>,
<boqun.feng@gmail.com>
Cc: <nixiaoming@huawei.com>, <wangle6@huawei.com>,
<xiaoqian9@huawei.com>, <shaolexi@huawei.com>
Subject: [PATCH] semaphore: Add might_sleep() to down_*() family
Date: Mon, 9 Aug 2021 10:12:15 +0800 [thread overview]
Message-ID: <20210809021215.19991-1-nixiaoming@huawei.com> (raw)
Semaphore is sleeping lock. Add might_sleep() to down*() family
(with exception of down_trylock()) to detect atomic context sleep.
Previously discussed with Peter Zijlstra, see link:
https://lore.kernel.org/lkml/20210806082320.GD22037@worktop.programming.kicks-ass.net
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
---
kernel/locking/semaphore.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/locking/semaphore.c b/kernel/locking/semaphore.c
index 9aa855a96c4a..9ee381e4d2a4 100644
--- a/kernel/locking/semaphore.c
+++ b/kernel/locking/semaphore.c
@@ -54,6 +54,7 @@ void down(struct semaphore *sem)
{
unsigned long flags;
+ might_sleep();
raw_spin_lock_irqsave(&sem->lock, flags);
if (likely(sem->count > 0))
sem->count--;
@@ -77,6 +78,7 @@ int down_interruptible(struct semaphore *sem)
unsigned long flags;
int result = 0;
+ might_sleep();
raw_spin_lock_irqsave(&sem->lock, flags);
if (likely(sem->count > 0))
sem->count--;
@@ -103,6 +105,7 @@ int down_killable(struct semaphore *sem)
unsigned long flags;
int result = 0;
+ might_sleep();
raw_spin_lock_irqsave(&sem->lock, flags);
if (likely(sem->count > 0))
sem->count--;
@@ -157,6 +160,7 @@ int down_timeout(struct semaphore *sem, long timeout)
unsigned long flags;
int result = 0;
+ might_sleep();
raw_spin_lock_irqsave(&sem->lock, flags);
if (likely(sem->count > 0))
sem->count--;
--
2.27.0
next reply other threads:[~2021-08-09 2:12 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-09 2:12 Xiaoming Ni [this message]
2021-08-09 3:01 ` [PATCH] semaphore: Add might_sleep() to down_*() family Waiman Long
2021-08-09 3:51 ` Xiaoming Ni
2021-08-09 12:52 ` Waiman Long
2021-08-09 14:33 ` Xiaoming Ni
2021-08-13 17:27 ` Thomas Gleixner
2021-08-13 18:47 ` Waiman Long
2021-08-13 14:43 ` Will Deacon
2021-08-23 9:39 ` [tip: locking/core] locking/semaphore: " tip-bot2 for Xiaoming Ni
2021-08-31 11:13 ` [PATCH] semaphore: " Guenter Roeck
2021-08-31 11:39 ` Hanjun Guo
2021-08-31 12:20 ` Thomas Gleixner
2021-08-31 11:40 ` Peter Zijlstra
2021-08-31 12:13 ` Thomas Gleixner
2021-08-31 12:34 ` Will Deacon
2021-08-31 17:42 ` Guenter Roeck
2021-09-01 8:37 ` [tip: smp/urgent] drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION() tip-bot2 for Thomas Gleixner
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