On Fri, May 25, 2018 at 11:05:06AM +0200, Anna-Maria Gleixner wrote:
> 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 wait_lock is no longer valid.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 <ebied...@xmission.com>
> Signed-off-by: Anna-Maria Gleixner <anna-ma...@linutronix.de>
Reviewed-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
Or let me know if you would like me to carry this patch. Either way,
just let me know!
Thanx, Paul
> ---
> 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
>
