Hillf Danton <[email protected]> wrote:
> > + smp_store_release(&buf->meta.head, head);
>
> Add a line of comment for the paring smp_load_acquire().
> I did not find it in 04/11.
You won't find smp_load_acquire() - it's not in the kernel, though if you look
in the sample, you'll find the corresponding barrier in userspace. Note that
there's a further implicit barrier you don't see.
I've added the comments:
/* Barrier against userspace, ordering data read before tail read */
ring_tail = READ_ONCE(buf->meta.tail);
and:
/* Barrier against userspace, ordering head update after data write. */
smp_store_release(&buf->meta.head, head);
David
