On 2026/4/27 22:45, Breno Leitao wrote:
On Mon, Apr 27, 2026 at 08:33:30PM +0800, Lance Yang wrote:
On Fri, Apr 24, 2026 at 05:23:59AM -0700, Breno Leitao wrote:
When get_hwpoison_page() returns a negative value, distinguish
reserved pages from other failure cases by reporting MF_MSG_KERNEL
instead of MF_MSG_GET_HWPOISON. Reserved pages belong to the kernel
and should be classified accordingly for proper handling.
Acked-by: Miaohe Lin <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
---
mm/memory-failure.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ee42d43613097..7b67e43dafbd1 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2432,7 +2432,16 @@ int memory_failure(unsigned long pfn, int flags)
}
goto unlock_mutex;
} else if (res < 0) {
- res = action_result(pfn, MF_MSG_GET_HWPOISON, MF_IGNORED);
+ /*
+ * PageReserved is stable here: reserved pages have
+ * PG_reserved set at boot or by drivers and are never
+ * freed through the page allocator.
+ */
Not necessarily. PG_reserved is not a permanent lifetime property for
every page that has carried it.
page-flags.h says early reserved pages may later have PG_reserved
cleared and then be given to the page allocator :)
At least some drivers also clear PG_reserved when releasing pages they
marked reserved.
Would it be clearer to say that pages with PG_reserved set are not
currently managed by the page allocator, rather than saying reserved
pages are never freed through the page allocator?
Would a comment like the following look better?
/*
* Pages with PG_reserved set are not currently managed by the
* page allocator (memblock-reserved memory, driver reservations,
* etc.), so classify them as kernel-owned for reporting.
*/
if (PageReserved(p))
res = action_result(pfn, MF_MSG_KERNEL, MF_IGNORED);
Works for me, thanks.
