The quilt patch titled
Subject: mm/huge_memory: use folio_mapcount() in zap_huge_pmd() sanity check
has been removed from the -mm tree. Its filename was
mm-huge_memory-use-folio_mapcount-in-zap_huge_pmd-sanity-check.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm/huge_memory: use folio_mapcount() in zap_huge_pmd() sanity check
Date: Tue, 9 Apr 2024 21:22:51 +0200
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary. Let's similarly check for folio_mapcount()
underflows instead of page_mapcount() underflows like we do in
zap_present_folio_ptes() now.
Instead of the VM_BUG_ON(), we should actually be doing something like
print_bad_pte(). For now, let's keep it simple and use WARN_ON_ONCE(),
performing that check independently of DEBUG_VM.
Link: https://lkml.kernel.org/r/20240409192301.907377-9-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Chris Zankel <chris@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Naoya Horiguchi <nao.horiguchi@xxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Richard Chang <richardycc@xxxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Yin Fengwei <fengwei.yin@xxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/huge_memory.c~mm-huge_memory-use-folio_mapcount-in-zap_huge_pmd-sanity-check
+++ a/mm/huge_memory.c
@@ -1791,7 +1791,7 @@ int zap_huge_pmd(struct mmu_gather *tlb,
folio = page_folio(page);
folio_remove_rmap_pmd(folio, page, vma);
- VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
+ WARN_ON_ONCE(folio_mapcount(folio) < 0);
VM_BUG_ON_PAGE(!PageHead(page), page);
} else if (thp_migration_supported()) {
swp_entry_t entry;
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
