Re: [PATCH net-next v7 1/5] mm: add a signature in struct page
From: Matthew Wilcox <willy@infradead.org>
Date: 2021-06-07 13:53:05
Also in:
bpf, linux-rdma, lkml, netdev
On Sun, Jun 06, 2021 at 03:50:54AM +0200, Matteo Croce wrote:
quoted hunk ↗ jump to hunk
And change all the *_pfmemalloc functions to use page->lru.next like this?@@ -1668,10 +1668,12 @@ struct address_space *page_mapping(struct page *page);static inline bool page_is_pfmemalloc(const struct page *page) { /* - * Page index cannot be this large so this must be - * a pfmemalloc page. + * This is not a tail page; compound_head of a head page is unused + * at return from the page allocator, and will be overwritten + * by callers who do not care whether the page came from the + * reserves. */
The comment doesn't make a lot of sense if we're switching to use lru.next. How about: /* * lru.next has bit 1 set if the page is allocated from the * pfmemalloc reserves. Callers may simply overwrite it if * they do not need to preserve that information. */