Re: [PATCH 5/8] mm/migrate.c: check pagelist in move_pages_and_store_status()

Michal Hocko
2020-01-20T09:52:20Z

On Sun 19-01-20 11:06:33, Wei Yang wrote:
> When pagelist is empty, it is not necessary to do the move and store.
> Also it consolidate the empty list check in one place.

OK looks good to me.

> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
> mm/migrate.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index dec147d3a4dd..46a5697b7fc6 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1499,9 +1499,6 @@ static int do_move_pages_to_node(struct mm_struct *mm,
> {
> int err;
>
> - if (list_empty(pagelist))
> - return 0;
> -
> err = migrate_pages(pagelist, alloc_new_node_page, NULL, node,
> MIGRATE_SYNC, MR_SYSCALL);
> if (err)
> @@ -1589,6 +1586,9 @@ static int move_pages_and_store_status(struct mm_struct *mm, int node,
> {
> int err;
>
> + if (list_empty(pagelist))
> + return 0;
> +
> err = do_move_pages_to_node(mm, pagelist, node);
> if (err)
> return err;
> @@ -1679,9 +1679,6 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
> 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 - start);
> --
> 2.17.1
>

--
Michal Hocko
SUSE Labs