We can already theoretically fail to unmap (still having page_mapped()) in
case arch_unmap_one() fails, which can happen on sparc. Failures to
unmap are handled gracefully, just as if there are other references on
the target page: freezing the refcount in split_huge_page_to_list()
will fail if still mapped and we'll simply remap.
In commit 504e070dc08f ("mm: thp: replace DEBUG_VM BUG with VM_WARN when
unmap fails for split") we already converted to VM_WARN_ON_ONCE_PAGE,
let's get rid of it completely now.
This is a preparation for making try_to_migrate() fail on anonymous pages
with GUP pins, which will make this VM_WARN_ON_ONCE_PAGE trigger more
frequently.
Reported-by: Yang Shi <shy828301@xxxxxxxxx>
Reviewed-by: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
mm/huge_memory.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0b6fb409b9e4..0fe0ab3ec3fc 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2263,8 +2263,6 @@ static void unmap_page(struct page *page)
try_to_migrate(page, ttu_flags);
else
try_to_unmap(page, ttu_flags | TTU_IGNORE_MLOCK);
-
- VM_WARN_ON_ONCE_PAGE(page_mapped(page), page);
}
static void remap_page(struct page *page, unsigned int nr)
--
2.35.1
--
Thanks,
David / dhildenb
