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From: Anna-Maria Gleixner <anna-maria@linutronix.de>
To: linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, bigeasy@linutronix.de,
	paulmck@linux.vnet.ibm.com, ebiederm@xmission.com,
	Anna-Maria Gleixner <anna-maria@linutronix.de>
Subject: [PATCH v2 1/2] rcu: Update documentation of rcu_read_unlock()
Date: Fri, 25 May 2018 11:05:06 +0200	[thread overview]
Message-ID: <20180525090507.22248-2-anna-maria@linutronix.de> (raw)
In-Reply-To: <20180525090507.22248-1-anna-maria@linutronix.de>

Since commit b4abf91047cf ("rtmutex: Make wait_lock irq safe") the
explanation in rcu_read_unlock() documentation about irq unsafe rtmutex
wait_lock is no longer valid.

Remove it to prevent kernel developers reading the documentation to rely on
it.

Suggested-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
---
 include/linux/rcupdate.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 36360d07f25b..64644fda3b22 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -653,9 +653,7 @@ static inline void rcu_read_lock(void)
  * Unfortunately, this function acquires the scheduler's runqueue and
  * priority-inheritance spinlocks.  This means that deadlock could result
  * if the caller of rcu_read_unlock() already holds one of these locks or
- * any lock that is ever acquired while holding them; or any lock which
- * can be taken from interrupt context because rcu_boost()->rt_mutex_lock()
- * does not disable irqs while taking ->wait_lock.
+ * any lock that is ever acquired while holding them.
  *
  * That said, RCU readers are never priority boosted unless they were
  * preempted.  Therefore, one way to avoid deadlock is to make sure
-- 
2.15.1

  reply	other threads:[~2018-05-25  9:05 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-25  9:05 [PATCH v2 0/2] rtmutex wait_lock is irq safe Anna-Maria Gleixner
2018-05-25  9:05 ` Anna-Maria Gleixner [this message]
2018-05-25 14:19   ` [PATCH v2 1/2] rcu: Update documentation of rcu_read_unlock() Paul E. McKenney
2018-05-28  9:49     ` Anna-Maria Gleixner
2018-06-10  4:18   ` [tip:core/urgent] " tip-bot for Anna-Maria Gleixner
2018-05-25  9:05 ` [PATCH v2 2/2] signal: Remove no longer required irqsave/restore Anna-Maria Gleixner
2018-06-10  4:19   ` [tip:core/urgent] " tip-bot for Anna-Maria Gleixner
2018-05-25 20:02 ` [PATCH v2 0/2] rtmutex wait_lock is irq safe Eric W. Biederman

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