Re: [PATCH] mm/page_poison: move PAGE_POISON to page_poison.c
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2018-02-09 16:23:53
Possibly related (same subject, not in this thread)
- 2018-02-26 · Re: [PATCH] mm/page_poison: move PAGE_POISON to page_poison.c · Wei Wang <hidden>
- 2018-02-13 · Re: [PATCH] mm/page_poison: move PAGE_POISON to page_poison.c · Michal Hocko <mhocko@kernel.org>
- 2018-02-09 · [PATCH] mm/page_poison: move PAGE_POISON to page_poison.c · Wei Wang <hidden>
On Fri, Feb 09, 2018 at 04:08:14PM +0800, Wei Wang wrote:
quoted hunk
The PAGE_POISON macro is used in page_poison.c only, so avoid exporting it. Also remove the "mm/debug-pagealloc.c" related comment, which is obsolete. Signed-off-by: Wei Wang <redacted> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michael S. Tsirkin <mst@redhat.com> --- include/linux/poison.h | 7 ------- mm/page_poison.c | 6 ++++++ 2 files changed, 6 insertions(+), 7 deletions(-)diff --git a/include/linux/poison.h b/include/linux/poison.h index 15927eb..348bf67 100644 --- a/include/linux/poison.h +++ b/include/linux/poison.h@@ -30,13 +30,6 @@ */ #define TIMER_ENTRY_STATIC ((void *) 0x300 + POISON_POINTER_DELTA) -/********** mm/debug-pagealloc.c **********/ -#ifdef CONFIG_PAGE_POISONING_ZERO -#define PAGE_POISON 0x00 -#else -#define PAGE_POISON 0xaa -#endif - /********** mm/page_alloc.c ************/ #define TAIL_MAPPING ((void *) 0x400 + POISON_POINTER_DELTA)
My question is, why are these macros kept in a single header. Is it so it's easy to figure out source of a crash by looking at the data and locating it in the file? If so we should keep it in the header, but fix the comment. If no there are more macros to move out, like flex array ones.
quoted hunk
diff --git a/mm/page_poison.c b/mm/page_poison.c index e83fd44..8aaf076 100644 --- a/mm/page_poison.c +++ b/mm/page_poison.c@@ -7,6 +7,12 @@ #include <linux/poison.h> #include <linux/ratelimit.h> +#ifdef CONFIG_PAGE_POISONING_ZERO +#define PAGE_POISON 0x00 +#else +#define PAGE_POISON 0xaa +#endif + static bool want_page_poisoning __read_mostly; static int early_page_poison_param(char *buf)-- 2.7.4