On 5/29/25 20:54, Mina Almasry wrote: ...>> #endif /* _LINUX_MM_H */
diff --git a/include/net/netmem.h b/include/net/netmem.h index f05a8b008d00..9e4ed3530788 100644 --- a/include/net/netmem.h +++ b/include/net/netmem.h @@ -53,6 +53,20 @@ NETMEM_DESC_ASSERT_OFFSET(pp_ref_count, pp_ref_count); */ static_assert(sizeof(struct netmem_desc) <= offsetof(struct page, _refcount)); +#ifdef CONFIG_PAGE_POOL +static inline bool page_pool_page_is_pp(struct page *page) +{ + struct netmem_desc *desc = (__force struct netmem_desc *)page; +Is it expected that page can be cast to netmem_desc freely? I know it works now since netmem_desc and page have the same layout, but how is it going to continue to work when page is shrunk and no longer has 'pp_magic' inside of it? Is that series going to fixup all the places where casts are done?
It's expected the struct page will have a type field once it's shrunk.
Is it also allowed that we can static cast netmem_desc to page? Consider creating netmem_desc_page helper like ptdesc_page. I'm not sure the __force is needed too.
-- Pavel Begunkov
