Re: [PATCH 01/18] drivers core: Add I/O ASID allocator

[Christoph Hellwig]

On Tue, Apr 09, 2019 at 01:00:49PM +0300, Andriy Shevchenko wrote:
> I think it makes sense to add a helper macro to rcupdate.h
> (and we have several cases in kernel that can utilize it)
> 
> #define kfree_non_null_rcu(ptr, rcu_head)		\
> 	do {						\
> 		if (ptr)				\
> 			kfree_rcu(ptr, rcu_head);	\
> 	} while (0)
> 
> as a more common pattern for resource deallocators.

I think that should move straight into kfree_rcu.  In general
we expect *free* to deal with NULL pointers transparently, so we
should do so here as well.