[PATCH 4.4 42/60] Fixes: Commit cdbf92675fad ("mm: numa: avoid waiting on freed migrated pages")

From: Greg Kroah-Hartman
Date: Thu Sep 13 2018 - 09:34:53 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------


From: Chas Williams <chas3@xxxxxxx>

Commit cdbf92675fad ("mm: numa: avoid waiting on freed migrated pages")
was an incomplete backport of the upstream commit. It is necessary to
always reset page_nid before attempting any early exit.

The original commit conflicted due to lack of commit 82b0f8c39a38
("mm: join struct fault_env and vm_fault") in 4.9 so it wasn't a clean
application, and the change must have just gotten lost in the noise.

Signed-off-by: Chas Williams <chas3@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1393,12 +1393,12 @@ int do_huge_pmd_numa_page(struct mm_stru

/* Migration could have started since the pmd_trans_migrating check */
if (!page_locked) {
+ page_nid = -1;
if (!get_page_unless_zero(page))
goto out_unlock;
spin_unlock(ptl);
wait_on_page_locked(page);
put_page(page);
- page_nid = -1;
goto out;
}