On 1/14/20 6:09 AM, Li Xinhai wrote:
Add cc to
Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
, who has been worked on this part
On 2020-01-14 at 17:16 Li Xinhai wrote:
Checking MPOL_MF_STRICT is ignored for HUGETLB vma according to mbind man
page:
Notes
MPOL_MF_STRICT is ignored on huge page mappings.
If MPOL_MF_STRICT is specified alone without any MOVE flag, we should
indicate, from test_walk, that walking this vma should be skipped even if
there are misplaced pages.
Signed-off-by: Li Xinhai <lixinhai.lxh@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
mm/mempolicy.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 067cf7d..c117b5f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -656,6 +656,13 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end,
return 1;
}
+ /* MPOL_MF_STRICT is ignored for huge page, skip checking
+ * misplaced pages
+ */
+ if ((flags & MPOL_MF_VALID) == MPOL_MF_STRICT &&
+ is_vm_hugetlb_page(vma))
+ return 1;
It makes some sense to me. We do save some effort by not
acquiring/releasing ptl and walking page tables.
Reviewed-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
/* queue pages from current vma */
if (flags & MPOL_MF_VALID)
return 0;
--
1.8.3.1
>
