Re: [PATCH net-next v5 1/5] mm: add a signature in struct page
From: Matthew Wilcox <willy@infradead.org>
Date: 2021-05-14 01:01:38
Also in:
bpf, linux-mm, linux-rdma, lkml
On Thu, May 13, 2021 at 06:58:42PM +0200, Matteo Croce wrote:
struct { /* page_pool used by netstack */
+ /**
+ * @pp_magic: magic value to avoid recycling non
+ * page_pool allocated pages.
+ * It aliases with page->lru.nextI'm not really keen on documenting what aliases with what. pp_magic also aliases with compound_head, 'next' (for slab), and dev_pagemap. This is an O(n^2) documentation problem ... I feel like I want to document the pfmemalloc bit in mm_types.h, but I don't have a concrete suggestion yet.
quoted hunk ↗ jump to hunk
+++ b/include/net/page_pool.h@@ -63,6 +63,8 @@ */ #define PP_ALLOC_CACHE_SIZE 128 #define PP_ALLOC_CACHE_REFILL 64 +#define PP_SIGNATURE (POISON_POINTER_DELTA + 0x40)
I wonder if this wouldn't be better in linux/poison.h?