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authorYang Shi <shy828301@gmail.com>2022-05-19 14:08:49 -0700
committerakpm <akpm@linux-foundation.org>2022-05-19 14:08:49 -0700
commit52b52bf15b67213c631dc8bee2a1854dd8811110 (patch)
tree5df888bf499d41160cdbf96592836ed973ca3080 /mm/khugepaged.c
parentcb648754a1d0dbac7cbcfe8d42cb27fa6063547d (diff)
downloadlinux-52b52bf15b67213c631dc8bee2a1854dd8811110.tar.bz2
mm: khugepaged: skip DAX vma
The DAX vma may be seen by khugepaged when the mm has other khugepaged suitable vmas. So khugepaged may try to collapse THP for DAX vma, but it will fail due to page sanity check, for example, page is not on LRU. So it is not harmful, but it is definitely pointless to run khugepaged against DAX vma, so skip it in early check. Link: https://lkml.kernel.org/r/20220510203222.24246-4-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Song Liu <song@kernel.org> Acked-by: Vlastmil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Song Liu <songliubraving@fb.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/khugepaged.c')
-rw-r--r--mm/khugepaged.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index e53b4826c7bd..647efd46b369 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -447,6 +447,10 @@ static bool hugepage_vma_check(struct vm_area_struct *vma,
if (vm_flags & VM_NO_KHUGEPAGED)
return false;
+ /* Don't run khugepaged against DAX vma */
+ if (vma_is_dax(vma))
+ return false;
+
if (vma->vm_file && !IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) -
vma->vm_pgoff, HPAGE_PMD_NR))
return false;