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Make wait_lock irq safe") the explanation in rcu_read_unlock() documentation about irq unsafe rtmutex wait_lock is no longer valid.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
next prev parent 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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