The quilt patch titled
Subject: mm: khugepaged: __collapse_huge_page_swapin() use pte_offset_map_ro_nolock()
has been removed from the -mm tree. Its filename was
mm-khugepaged-__collapse_huge_page_swapin-use-pte_offset_map_ro_nolock.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: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Subject: mm: khugepaged: __collapse_huge_page_swapin() use pte_offset_map_ro_nolock()
Date: Thu, 26 Sep 2024 14:46:17 +0800
In __collapse_huge_page_swapin(), we just use the ptl for pte_same() check
in do_swap_page(). In other places, we directly use
pte_offset_map_lock(), so convert it to using pte_offset_map_ro_nolock().
Link: https://lkml.kernel.org/r/dc97a6c3cb9ea80cab30c5626eeea79959d93258.1727332572.git.zhengqi.arch@xxxxxxxxxxxxx
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/khugepaged.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/mm/khugepaged.c~mm-khugepaged-__collapse_huge_page_swapin-use-pte_offset_map_ro_nolock
+++ a/mm/khugepaged.c
@@ -1014,7 +1014,11 @@ static int __collapse_huge_page_swapin(s
};
if (!pte++) {
- pte = pte_offset_map_nolock(mm, pmd, address, &ptl);
+ /*
+ * Here the ptl is only used to check pte_same() in
+ * do_swap_page(), so readonly version is enough.
+ */
+ pte = pte_offset_map_ro_nolock(mm, pmd, address, &ptl);
if (!pte) {
mmap_read_unlock(mm);
result = SCAN_PMD_NULL;
_
Patches currently in -mm which might be from zhengqi.arch@xxxxxxxxxxxxx are
