From c31783eeae7b22dc3f6edde7339de6112959225d Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 21 Oct 2022 12:11:38 +0200 Subject: [PATCH] mm/pagewalk: don't trigger test_walk() in walk_page_vma() As Peter points out, the caller passes a single VMA and can just do that check itself. And in fact, no existing users rely on test_walk() getting called. So let's just remove it and make the implementation slightly more efficient. Link: https://lkml.kernel.org/r/20221021101141.84170-7-david@redhat.com Signed-off-by: David Hildenbrand Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: John Hubbard Cc: Matthew Wilcox (Oracle) Cc: Peter Xu Cc: Shuah Khan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/pagewalk.h | 2 ++ mm/pagewalk.c | 7 ------- 2 files changed, 2 insertions(+), 7 deletions(-) diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h index f3fafb7..37dc020 100644 --- a/include/linux/pagewalk.h +++ b/include/linux/pagewalk.h @@ -27,6 +27,8 @@ struct mm_walk; * "do page table walk over the current vma", returning * a negative value means "abort current page table walk * right now" and returning 1 means "skip the current vma" + * Note that this callback is not called when the caller + * passes in a single VMA as for walk_page_vma(). * @pre_vma: if set, called before starting walk on a non-null vma. * @post_vma: if set, called after a walk on a non-null vma, provided * that @pre_vma and the vma walk succeeded. diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 2ff3a5b..0a5d71a 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -526,18 +526,11 @@ int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, .vma = vma, .private = private, }; - int err; if (!walk.mm) return -EINVAL; mmap_assert_locked(walk.mm); - - err = walk_page_test(vma->vm_start, vma->vm_end, &walk); - if (err > 0) - return 0; - if (err < 0) - return err; return __walk_page_range(vma->vm_start, vma->vm_end, &walk); } -- 2.7.4