Re: [PATCH RFC v2 1/7] mm: memory_failure: Clarify the MF_DELAYED definition

Jiaqi Yan
2026-03-22T21:35:15Z

On Thu, Mar 19, 2026 at 4:30 PM Lisa Wang <wyihan@google.com> wrote:
>
> This patch clarifies the definition of MF_DELAYED to represent cases
> where a folio's removal is initiated but not immediately completed
> (e.g., due to remaining metadata references).
>
> Signed-off-by: Lisa Wang <wyihan@google.com>
> ---
> mm/memory-failure.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index ee42d4361309..4f143334d5a1 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -862,9 +862,10 @@ static int kill_accessing_process(struct task_struct *p, unsigned long pfn,
> * by the m-f() handler immediately.
> *
> * MF_DELAYED - The m-f() handler marks the page as PG_hwpoisoned'ed.

nit: would it be worth correcting PG_hwpoisoned to PG_hwpoison'ed? as
there is really no "PG_hwpoisoned" page flag.

> - * The page is unmapped, and is removed from the LRU or file mapping.
> - * An attempt to access the page again will trigger page fault and the
> - * PF handler will kill the process.
> + * It means the page was partially isolated (e.g. removed from file mapping

nit: what about "unmapped"?

> + * or the LRU) but full cleanup is deferred (e.g. the metadata for the
> + * memory, as in struct page/folio, is still referenced). Any further
> + * access to the page will result in the process being killed.
> *
> * MF_RECOVERED - The m-f() handler marks the page as PG_hwpoisoned'ed.
> * The page has been completely isolated, that is, unmapped, taken out of
>
> --
> 2.53.0.959.g497ff81fa9-goog
>

Reviewed-by: Jiaqi Yan <jiaqiyan@google.com>