On 2018-12-17 16:29, Michal Hocko wrote:
On Mon 17-12-18 16:06:51, Oscar Salvador wrote:
[...]
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a6e7bfd18cde..18d41e85f672 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8038,11 +8038,12 @@ bool has_unmovable_pages(struct zone *zone,
struct page *page, int count,
* handle each tail page individually in migration.
*/
if (PageHuge(page)) {
+ struct page *head = compound_head(page);
- if (!hugepage_migration_supported(page_hstate(page)))
+ if (!hugepage_migration_supported(page_hstate(head)))
goto unmovable;
OK, this makes sense.
- iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
+ iter = round_up(iter + 1, 1<<compound_order(head)) - 1;
but this less so. You surely do not want to move by the full hugetlb
page when you got a tail page, right? You could skip too much. You have
to consider page - head into the equation.
Argh, you're quite right.
I will amend it in the next version.
