On Thu, May 25, 2023 at 1:26 PM Mike Rapoport <rppt@xxxxxxxxxx> wrote:
On Thu, May 25, 2023 at 11:04:28AM -0700, Vishal Moola wrote:
On Thu, May 25, 2023 at 2:10 AM Mike Rapoport <rppt@xxxxxxxxxx> wrote:
+
+static inline struct ptdesc *ptdesc_alloc(gfp_t gfp, unsigned int order)
+{
+ struct page *page = alloc_pages(gfp | __GFP_COMP, order);
+
+ return page_ptdesc(page);
+}
+
+static inline void ptdesc_free(struct ptdesc *pt)
+{
+ struct page *page = ptdesc_page(pt);
+
+ __free_pages(page, compound_order(page));
+}
The ptdesc_{alloc,free} API does not sound right to me. The name
ptdesc_alloc() implies the allocation of the ptdesc itself, rather than
allocation of page table page. The same goes for free.
I'm not sure I see the difference. Could you elaborate?
I read ptdesc_alloc() as "allocate a ptdesc" rather than as "allocate a
page for page table and return ptdesc pointing to that page". Seems very
confusing to me already and it will be even more confusion when we'll start
allocating actual ptdescs.
Hmm, I see what you're saying. I'm envisioning this function evolving into
one that allocates a ptdesc later. I don't see why we would need to have both a
page table page AND ptdesc at any point, but that may be a lack of knowledge
from my part.
I was thinking later, if necessary, we could make another function
(only to be used internally) to allocate page table pages.
