On Tue, 5 Mar 2024 at 20:37, Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
>
> +static struct page *dump_page_copy(struct page *src, struct page *dst)
> +{
> + return NULL;
> +}
No, it needs to be "return src;" not NULL.
That
#define dump_page_copy(src, dst) ((dst), (src))
was supposed to be a "use 'dst', return 'src'" macro, and is correct
as that. The problem - as you noticed - is that it causes that "left
side of comma expression has no effect" warning.
(Technically it *does* have an effect - exactly the "argument is used"
one - but the compiler warning does make sense).
Actually, the simplest thing to do is probably just
#define dump_page_free(x) ((void)(x))
#define dump_page_copy(src, dst) (src)
where the "use" of the 'dump_page' argument is that dump_page_free()
void cast, and dump_page_copy() simply doesn't need to use it at all.
Christian?
Linus
