The pmd_devmap() check in check_pmd_state() is redundant because the
only user of pmd_devmap were device dax and fs dax. However all callers
of check_pmd_state() first call thp_vma_allowable_order() to check if
the vma should be scanned. Except when called from a page fault this
always returns 0 for dax vma's, hence we would never expect to see a
pmd_devmap entry.
Signed-off-by: Alistair Popple <apop...@nvidia.com>
Acked-by: David Hildenbrand <da...@redhat.com>
Reviewed-by: Jason Gunthorpe <j...@nvidia.com>
---
Changes from v2:
- Update commit message to better reflect why the check was redundant
---
mm/khugepaged.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 15203ea..d45d08b 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -945,8 +945,6 @@ static inline int check_pmd_state(pmd_t *pmd)
return SCAN_PMD_NULL;
if (pmd_trans_huge(pmde))
return SCAN_PMD_MAPPED;
- if (pmd_devmap(pmde))
- return SCAN_PMD_NULL;
if (pmd_bad(pmde))
return SCAN_PMD_NULL;
return SCAN_SUCCEED;
--
git-series 0.9.1
