[PATCH v2 05/14] mm: khugepaged: __collapse_huge_page_swapin() use pte_offset_map_ro_nolock()
From: Qi Zheng <hidden>
Date: 2024-08-22 07:14:17
Also in:
linux-arm-kernel, linux-mm, lkml
Subsystem:
memory management, memory management - thp (transparent huge page), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Linus Torvalds
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(). Signed-off-by: Qi Zheng <redacted> --- mm/khugepaged.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 4a83c40d90538..53bfa7f4b7f82 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c@@ -1011,7 +1011,11 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm, }; 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;
--
2.20.1