Messages in this thread | | | Date | Mon, 28 May 2018 11:49:06 +0200 (CEST) | From | Anna-Maria Gleixner <> | Subject | Re: [PATCH v2 1/2] rcu: Update documentation of rcu_read_unlock() |
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On Fri, 25 May 2018, Paul E. McKenney wrote:
> 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 wait_lock is no longer valid.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 <ebiederm@xmission.com> > > Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> > > Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > > Or let me know if you would like me to carry this patch. Either way, > just let me know! >
Thanks! Thomas told be he will take both.
Anna-Maria
> > > --- > > 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 > > > >
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