From a75966d76de46cb6af37921fa71bc99659fd946f Mon Sep 17 00:00:00 2001 From: Anna-Maria Gleixner Date: Mon, 2 Aug 2021 21:46:24 +0800 Subject: rcu: Update documentation of rcu_read_unlock() [ Upstream commit ec84b27f9b3b569f9235413d1945a2006b97b0aa ] 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Make wait_lock irq safe") the explanation in rcu_read_unlock() documentation about irq unsafe rtmutex wait_lock is no longer valid.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 Signed-off-by: Anna-Maria Gleixner Signed-off-by: Thomas Gleixner Reviewed-by: Paul E. McKenney Acked-by: "Eric W. Biederman" Cc: bigeasy@linutronix.de Link: https://lkml.kernel.org/r/20180525090507.22248-2-anna-maria@linutronix.de Signed-off-by: Zhen Lei Acked-by: Joe Korty Signed-off-by: Greg Kroah-Hartman --- include/linux/rcupdate.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 0a93e9d1708e..3072e9c93ae6 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -880,9 +880,7 @@ static __always_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 -- cgit v1.2.3