On 3/19/19 5:49 PM, David Rientjes wrote:
On Wed, 20 Mar 2019, Yang Shi wrote:
When MPOL_MF_STRICT was specified and an existing page was already on a node that does not follow the policy, mbind() should return -EIO. But commit 6f4576e3687b ("mempolicy: apply page table walker on queue_pages_range()") broke the rule.
And, commit c8633798497c ("mm: mempolicy: mbind and migrate_pages support thp migration") didn't return the correct value for THP mbind() too.
If MPOL_MF_STRICT is set, ignore vma_migratable() to make sure it reaches queue_pages_to_pte_range() or queue_pages_pmd() to check if an existing page was already on a node that does not follow the policy. And, non-migratable vma may be used, return -EIO too if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL was specified.
Tested with https://github.com/metan-ucw/ltp/blob/master/testcases/kernel/syscalls/mbind...
Fixes: 6f4576e3687b ("mempolicy: apply page table walker on queue_pages_range()") Reported-by: Cyril Hrubis chrubis@suse.cz Cc: Vlastimil Babka vbabka@suse.cz Cc: stable@vger.kernel.org Suggested-by: Kirill A. Shutemov kirill@shutemov.name Signed-off-by: Yang Shi yang.shi@linux.alibaba.com Signed-off-by: Oscar Salvador osalvador@suse.de
Acked-by: David Rientjes rientjes@google.com
Thanks. I think this needs stable for 4.0+, can you confirm?
Thanks. Yes, this needs stable for 4.0+.
Yang