From 64b586d1922384710de2ce3c8c67e7ea0b6ffb57 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Wed, 7 Jul 2021 13:06:17 -0700 Subject: [PATCH] mm/rmap: fix comments left over from recent changes Parallel developments in mm/rmap.c have left behind some out-of-date comments: try_to_migrate_one() also accepts TTU_SYNC (already commented in try_to_migrate() itself), and try_to_migrate() returns nothing at all. TTU_SPLIT_FREEZE has just been deleted, so reword the comment about it in mm/huge_memory.c; and TTU_IGNORE_ACCESS was removed in 5.11, so delete the "recently referenced" comment from try_to_unmap_one() (once upon a time the comment was near the removed codeblock, but they drifted apart). Signed-off-by: Hugh Dickins Reviewed-by: Shakeel Butt Reviewed-by: Alistair Popple Link: https://lore.kernel.org/lkml/563ce5b2-7a44-5b4d-1dfd-59a0e65932a9@google.com/ Cc: Andrew Morton Cc: Jason Gunthorpe Cc: Ralph Campbell Cc: Christoph Hellwig Cc: Yang Shi Cc: Kirill A. Shutemov Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 2 +- mm/rmap.c | 7 +------ 2 files changed, 2 insertions(+), 7 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 8b731d5..afff3ac 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2331,7 +2331,7 @@ static void remap_page(struct page *page, unsigned int nr) { int i; - /* If TTU_SPLIT_FREEZE is ever extended to file, remove this check */ + /* If unmap_page() uses try_to_migrate() on file, remove this check */ if (!PageAnon(page)) return; if (PageTransHuge(page)) { diff --git a/mm/rmap.c b/mm/rmap.c index 37c2467..746013e 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1439,8 +1439,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, while (page_vma_mapped_walk(&pvmw)) { /* * If the page is mlock()d, we cannot swap it out. - * If it's recently referenced (perhaps page_referenced - * skipped over this mm) then we should reactivate it. */ if (!(flags & TTU_IGNORE_MLOCK)) { if (vma->vm_flags & VM_LOCKED) { @@ -1687,8 +1685,7 @@ void try_to_unmap(struct page *page, enum ttu_flags flags) * @arg: enum ttu_flags will be passed to this argument. * * If TTU_SPLIT_HUGE_PMD is specified any PMD mappings will be split into PTEs - * containing migration entries. This and TTU_RMAP_LOCKED are the only supported - * flags. + * containing migration entries. */ static bool try_to_migrate_one(struct page *page, struct vm_area_struct *vma, unsigned long address, void *arg) @@ -1928,8 +1925,6 @@ static bool try_to_migrate_one(struct page *page, struct vm_area_struct *vma, * * Tries to remove all the page table entries which are mapping this page and * replace them with special swap entries. Caller must hold the page lock. - * - * If is successful, return true. Otherwise, false. */ void try_to_migrate(struct page *page, enum ttu_flags flags) { -- 2.7.4