Re: Question on (locking: Make spinlock_t and rwlock_t a RCU section on RT)

[Sebastian Andrzej Siewior]

On 2021-07-26 07:43:33 [+0000], Zhang, Qiang wrote:
> Operation of sleep is not allowed in RCU read critical area,  If
> after acquiring a rt-spinlock , try to acquire another one
> rt-spinlock,  This may cause sleep, and trigger RCU warning.  
> 
> Is there a problem with my analysis or something I missed?

This warning is suppressed on RT. Same as on CONFIG_PREEMPT when a task
gets preempted while in a rcu_read_lock() section.

> Thanks
> Qiang

Sebastian