Re: [PATCH v8 3/6] mm/memory-failure: report MF_MSG_KERNEL for unrecoverable kernel pages

[Miaohe Lin]

On 2026/5/27 22:06, Breno Leitao wrote:
> The previous patch teaches get_any_page() to return -ENOTRECOVERABLE
> for stable unhandlable kernel pages (PG_reserved, slab, page tables,
> large-kmalloc).  memory_failure() still folds every negative return
> into MF_MSG_GET_HWPOISON, so callers that want to react to the
> unrecoverable cases (a panic option, smarter logging) cannot tell
> them apart from transient page-allocator races.
> 
> Turn the post-call branch into a switch over the get_hwpoison_page()
> return code: map -ENOTRECOVERABLE to MF_MSG_KERNEL and any other
> negative return to MF_MSG_GET_HWPOISON.  case 0 keeps the existing
> free-buddy / kernel-high-order handling and case 1 falls through to
> the rest of memory_failure() unchanged.
> 
> The MF_MSG_KERNEL label and tracepoint string are kept as
> "reserved kernel page" to avoid breaking userspace tools that match
> on those literals; the enum value still adequately tags the failure
> even though it now also covers slab, page tables and large-kmalloc
> pages.
> 
> Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
> Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>

Acked-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>

Thanks.
.