On Thu, Aug 22, 2024 at 07:42:20PM +0100, Matthew Wilcox wrote:
> On Thu, Aug 22, 2024 at 11:23:04AM -0600, Yu Zhao wrote:
> > Andrew, could you patch up the line above? This is what it's supposed
> > to check:
> >
> > diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> > index 59266df56aeb..03ba9563c6db 100644
> > --- a/include/linux/gfp.h
> > +++ b/include/linux/gfp.h
> > @@ -452,7 +452,7 @@ static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
> > {
> > struct page *page;
> >
> > - if (WARN_ON(!order || !(gfp | __GFP_COMP)))
> > + if (WARN_ON(!order || !(gfp & __GFP_COMP)))
> > return NULL;
>
> I don't think we should do this at all. Just this should be enough:
>
> gfp |= __GFP_COMP;
>
> same as folio_alloc() (or now folio_alloc_noprof()).
> Do we really caree if somebody tries to allocate a gigantic page with an
> order of 0?
If this ever happens, I'd bet it's a bug.
> It's weird, but would work, so I don't see the need for the
> warning.
So the warning could catch that, but if we think it's verbose, then
please fold the following in:
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index a951de920e20..b43934d79dd9 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -452,10 +452,7 @@ static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
{
struct page *page;
- if (WARN_ON(!order || !(gfp & __GFP_COMP)))
- return NULL;
-
- page = alloc_contig_pages_noprof(1 << order, gfp, nid, node);
+ page = alloc_contig_pages_noprof(1 << order, gfp | __GFP_COMP, nid, node);
return page ? page_folio(page) : NULL;
}
