diff mbox series

[RFC,06/13] mm/rmap: pass rmap flags to hugepage_add_anon_rmap()

Message ID 20220224122614.94921-7-david@redhat.com (mailing list archive)
State New
Headers show
Series mm: COW fixes part 2: reliable GUP pins of anonymous pages | expand

Commit Message

David Hildenbrand Feb. 24, 2022, 12:26 p.m. UTC 
Let's prepare for passing RMAP_EXCLUSIVE, similarly as we do for
page_add_anon_rmap() now. RMAP_COMPOUND is implicit for hugetlb
pages and ignored.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 include/linux/rmap.h | 2 +-
 mm/migrate.c         | 2 +-
 mm/rmap.c            | 8 +++++---
 3 files changed, 7 insertions(+), 5 deletions(-)

Comments

Linus Torvalds Feb. 24, 2022, 5:37 p.m. UTC | #1 
On Thu, Feb 24, 2022 at 4:30 AM David Hildenbrand <david@redhat.com> wrote:
>
> -                               hugepage_add_anon_rmap(new, vma, pvmw.address);
> +                               hugepage_add_anon_rmap(new, vma, pvmw.address, 0);

This now has the same "what does 0 mean?" issue.

(And grepping for RMAP_, I notice that we have a namespace clash, with
xfs and kvm also using "RMAP_xyz" for their own things. Oh wel, at
least they don't look like they'd ever mix).

            Linus
diff mbox series

Patch

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index f230e86b4587..593a4566420f 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -174,7 +174,7 @@  void page_add_file_rmap(struct page *, bool);
 void page_remove_rmap(struct page *, bool);
 
 void hugepage_add_anon_rmap(struct page *, struct vm_area_struct *,
-			    unsigned long);
+			    unsigned long, int);
 void hugepage_add_new_anon_rmap(struct page *, struct vm_area_struct *,
 				unsigned long);
 
diff --git a/mm/migrate.c b/mm/migrate.c
index d4d72a15224c..709cb11d5b81 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -238,7 +238,7 @@  static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
 			pte = pte_mkhuge(pte);
 			pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
 			if (PageAnon(new))
-				hugepage_add_anon_rmap(new, vma, pvmw.address);
+				hugepage_add_anon_rmap(new, vma, pvmw.address, 0);
 			else
 				page_dup_file_rmap(new, true);
 			set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
diff --git a/mm/rmap.c b/mm/rmap.c
index 902ebf99d147..bafdb7f70cec 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -2409,9 +2409,11 @@  void rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc)
  * The following two functions are for anonymous (private mapped) hugepages.
  * Unlike common anonymous pages, anonymous hugepages have no accounting code
  * and no lru code, because we handle hugepages differently from common pages.
+ *
+ * RMAP_COMPOUND is ignored.
  */
-void hugepage_add_anon_rmap(struct page *page,
-			    struct vm_area_struct *vma, unsigned long address)
+void hugepage_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
+			    unsigned long address, int flags)
 {
 	struct anon_vma *anon_vma = vma->anon_vma;
 	int first;
@@ -2421,7 +2423,7 @@  void hugepage_add_anon_rmap(struct page *page,
 	/* address might be in next vma when migration races vma_adjust */
 	first = atomic_inc_and_test(compound_mapcount_ptr(page));
 	if (first)
-		__page_set_anon_rmap(page, vma, address, 0);
+		__page_set_anon_rmap(page, vma, address, flags & RMAP_EXCLUSIVE);
 }
 
 void hugepage_add_new_anon_rmap(struct page *page,