On Thu, 21 Dec 2023 12:58:13 -0500
Steven Rostedt <rost...@goodmis.org> wrote:
> On Thu, 21 Dec 2023 17:35:22 +0000
> Vincent Donnefort <vdonnef...@google.com> wrote:
>
> > @@ -5999,6 +6078,307 @@ int ring_buffer_subbuf_order_set(struct
> > trace_buffer *buffer, int order)
> > }
> > EXPORT_SYMBOL_GPL(ring_buffer_subbuf_order_set);
> >
>
> The kernel developers have agreed to allow loop variables to be declared in
> loops. This will simplify these macros:
>
>
>
> > +#define subbuf_page(off, start) \
> > + virt_to_page((void *)(start + (off << PAGE_SHIFT)))
> > +
> > +#define foreach_subbuf_page(off, sub_order, start, page) \
> > + for (off = 0, page = subbuf_page(0, start); \
> > + off < (1 << sub_order); \
> > + off++, page = subbuf_page(off, start))
>
> #define foreach_subbuf_page(sub_order, start, page) \
> for (int __off = 0, page = subbuf_page(0, (start)); \
> __off < (1 << (sub_order)); \
> __off++, page = subbuf_page(__off, (start)))
So it seems that you can't declare "int __off" with page there, but we
could have:
#define foreach_subbuf_page(sub_order, start, page) \
page = subbuf_page(0, (start)); \
for (int __off = 0; __off < (1 << (sub_order)); \
__off++, page = subbuf_page(__off, (start)))
And that would work.
-- Steve
