Re: [PATCH net-next v7 1/5] mm: add a signature in struct page
From: Matthew Wilcox <willy@infradead.org>
Date: 2021-06-04 19:08:31
Also in:
bpf, linux-rdma, lkml, netdev
On Fri, Jun 04, 2021 at 08:33:45PM +0200, Matteo Croce wrote:
quoted hunk ↗ jump to hunk
@@ -130,7 +137,10 @@ struct page { }; }; struct { /* Tail pages of compound page */ - unsigned long compound_head; /* Bit zero is set */ + /* Bit zero is set + * Bit one if pfmemalloc page + */ + unsigned long compound_head;
I would drop this hunk. Bit 1 is not used for this purpose in tail
pages; it's used for that purpose in head and base pages.
I suppose we could do something like ...
static inline void set_page_pfmemalloc(struct page *page)
{
- page->index = -1UL;
+ page->lru.next = (void *)2;
}
if it's causing confusion.