From: Miaohe Lin linmiaohe@huawei.com
stable inclusion from linux-4.19.191 commit fdacfd77695f8c279bc7334cd1bea50c28bf4729
--------------------------------
[ Upstream commit 74e579bf231a337ab3786d59e64bc94f45ca7b3f ]
In writable and !referenced case, the result value should be SCAN_LACK_REFERENCED_PAGE for trace_mm_collapse_huge_page_isolate() instead of default 0 (SCAN_FAIL) here.
Link: https://lkml.kernel.org/r/20210306032947.35921-5-linmiaohe@huawei.com Fixes: 7d2eba0557c1 ("mm: add tracepoint for scanning pages") Signed-off-by: Miaohe Lin linmiaohe@huawei.com Acked-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Cc: Dan Carpenter dan.carpenter@oracle.com Cc: Ebru Akagunduz ebru.akagunduz@gmail.com Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Rik van Riel riel@redhat.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- mm/khugepaged.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index ad386978d7e05..55f171ed2d08a 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -616,17 +616,17 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, mmu_notifier_test_young(vma->vm_mm, address)) referenced++; } - if (likely(writable)) { - if (likely(referenced)) { - result = SCAN_SUCCEED; - trace_mm_collapse_huge_page_isolate(page, none_or_zero, - referenced, writable, result); - return 1; - } - } else { + + if (unlikely(!writable)) { result = SCAN_PAGE_RO; + } else if (unlikely(!referenced)) { + result = SCAN_LACK_REFERENCED_PAGE; + } else { + result = SCAN_SUCCEED; + trace_mm_collapse_huge_page_isolate(page, none_or_zero, + referenced, writable, result); + return 1; } - out: release_pte_pages(pte, _pte); trace_mm_collapse_huge_page_isolate(page, none_or_zero,