Re: WARNING in memory_failure() at include/linux/huge_mm.h:635 triggered

[Zi Yan <ziy@nvidia.com>]

On 4 Feb 2026, at 16:37, David Hildenbrand (arm) wrote:

> On 2/4/26 22:08, Zi Yan wrote:
>> On 4 Feb 2026, at 14:18, David Hildenbrand (arm) wrote:
>>
>>> On 2/4/26 18:41, Zi Yan wrote:
>>>>
>>>>
>>>> More details:
>>>> later at sg_vma_fault(), the driver just handles a page fault by supplying
>>>> a subpage from a pre-allocated compound page[3]. We then get a large folio
>>>> without !CONFIG_TRANSPARENT_HUGEPAGE.
>>>
>>> We can identify such non-folio (but compound) things by looking at PG_large_rmappable IIRC.
>>
>> OK, back to the issue. The patch below should fix the issue?
>>
>> Hi 是参差,
>>
>> Can you test it?
>>

<snip>
> I think you have to test for folio_test_large() before testing folio_test_large_rmappable().

Oh, forgot that. Thanks.


From 8dda4bba9964890462eca3ef3cce57bb4fab8313 Mon Sep 17 00:00:00 2001
From: Zi Yan <ziy@nvidia.com>
Date: Wed, 4 Feb 2026 16:04:19 -0500
Subject: [PATCH] mm/memory_failure: reject unsupported non-folio compound page

Signed-off-by: Zi Yan <ziy@nvidia.com>
---
 mm/memory-failure.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 825c706ac576..137c67fda57e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2440,9 +2440,13 @@ int memory_failure(unsigned long pfn, int flags)

 	folio = page_folio(p);

-	/* filter pages that are protected from hwpoison test by users */
+	/*
+	 * filter pages that are protected from hwpoison test by users
+	 * or unsupported non folio compound pages
+	 */
 	folio_lock(folio);
-	if (hwpoison_filter(p)) {
+	if (hwpoison_filter(p) ||
+	    (folio_test_large(folio) && !folio_test_large_rmappable(folio))) {
 		ClearPageHWPoison(p);
 		folio_unlock(folio);
 		folio_put(folio);
-- 
2.51.0



Best Regards,
Yan, Zi