We don't have native support of THP migration, so we have to split huge page into small pages in order to migrate it to different node. This includes PTE-mapped huge pages. I made mistake in refcounting patchset: we don't actually split PTE-mapped huge page in queue_pages_pte_range(), if we step on head page. The result is that the head page is queued for migration, but none of tail pages: putting head page on queue takes pin on the page and any subsequent attempts of split_huge_pages() would fail and we skip queuing tail pages. unmap_and_move_huge_page() will eventually split the huge pages, but only one of 512 pages would get migrated. Let's fix the situation. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Fixes: b57a81e3e29c ("migrate_pages: try to split pages on queuing") --- mm/mempolicy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 8c5fd08c253c..8cbc74387df3 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -532,7 +532,7 @@ retry: nid = page_to_nid(page); if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT)) continue; - if (PageTail(page) && PageAnon(page)) { + if (PageTransCompound(page) && PageAnon(page)) { get_page(page); pte_unmap_unlock(pte, ptl); lock_page(page); -- 2.7.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>