From: Anna-Maria Gleixner anna-maria@linutronix.de
[ 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Make wait_lock irq safe") the explanation in rcu_read_unlock() documentation about irq unsafe rtmutex wait_lock is no longer valid.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 ebiederm@xmission.com Signed-off-by: Anna-Maria Gleixner anna-maria@linutronix.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Paul E. McKenney paulmck@linux.vnet.ibm.com Acked-by: "Eric W. Biederman" ebiederm@xmission.com Cc: bigeasy@linutronix.de Link: https://lkml.kernel.org/r/20180525090507.22248-2-anna-maria@linutronix.de Signed-off-by: Zhen Lei thunder.leizhen@huawei.com --- 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 0a93e9d1708e29e..3072e9c93ae6be2 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