[patch 014/166] mm/migrate.c: check pagelist in move_pages_and_store_status()

Andrew Morton
2020-04-07T03:04:18Z

From: Wei Yang <richardw.yang@linux.intel.com>
Subject: mm/migrate.c: check pagelist in move_pages_and_store_status()

When pagelist is empty, it is not necessary to do the move and store.
Also it consolidate the empty list check in one place.

Link: http://lkml.kernel.org/r/20200214003017.25558-4-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

mm/migrate.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

--- a/mm/migrate.c~mm-migratec-check-pagelist-in-move_pages_and_store_status
+++ a/mm/migrate.c
@@ -1518,9 +1518,6 @@ static int do_move_pages_to_node(struct
{
int err;

- if (list_empty(pagelist))
- return 0;
-
err = migrate_pages(pagelist, alloc_new_node_page, NULL, node,
MIGRATE_SYNC, MR_SYSCALL);
if (err)
@@ -1608,6 +1605,9 @@ static int move_pages_and_store_status(s
{
int err;

+ if (list_empty(pagelist))
+ return 0;
+
err = do_move_pages_to_node(mm, pagelist, node);
if (err) {
/*
@@ -1705,9 +1705,6 @@ static int do_pages_move(struct mm_struc
current_node = NUMA_NO_NODE;
}
out_flush:
- if (list_empty(&pagelist))
- return err;
-
/* Make sure we do not overwrite the existing error */
err1 = move_pages_and_store_status(mm, current_node, &pagelist,
status, start, i, nr_pages);
_