Re: [Patch v2 1/4] mm/migrate.c: not necessary to check start and i

From: David Hildenbrand
Date: Tue Jan 28 2020 - 05:04:34 EST


On 22.01.20 02:16, Wei Yang wrote:
> Till here, i must no less than start. And if i equals to start,
> store_status() would always return 0.

I'd suggest

"
mm/migrate.c: no need to check for i > start in do_pages_move()

At this point, we always have i >= start. If i == start, store_status()
will return 0. So we can drop the check for i > start.
"

Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>

>
> Remove some unnecessary check to make it easy to read and prepare for
> further cleanup.
>
> Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
> Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
> mm/migrate.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 430fdccc733e..4c2a21856717 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1661,11 +1661,9 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
> err = do_move_pages_to_node(mm, &pagelist, current_node);
> if (err)
> goto out;
> - if (i > start) {
> - err = store_status(status, start, current_node, i - start);
> - if (err)
> - goto out;
> - }
> + err = store_status(status, start, current_node, i - start);
> + if (err)
> + goto out;
> current_node = NUMA_NO_NODE;
> }
> out_flush:
>


--
Thanks,

David / dhildenb