On Thu, 03 Oct 2019 09:39:17 +0100
David Howells <dhowells@xxxxxxxxxx> wrote:
> paulmck@xxxxxxxxxx wrote:
>
> > +#define rcu_replace(rcu_ptr, ptr, c) \
> > +({ \
> > + typeof(ptr) __tmp = rcu_dereference_protected((rcu_ptr), (c)); \
> > + rcu_assign_pointer((rcu_ptr), (ptr)); \
> > + __tmp; \
> > +})
>
> Does it make sense to actually use xchg() if that's supported by the arch?
>
Hmm, is there really any arch that doesn't support xchg()? It would be
very hard to do any kind of atomic operations without it.
cmpxchg() is the one that I understand is optional by the arch.
-- Steve
