lkml.org 
[lkml]   [2023]   [Aug]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] mm/page_alloc: remove unneeded current_order check
On Tue, 8 Aug 2023 10:05:55 +0800
Miaohe Lin <linmiaohe@huawei.com> wrote:

> current_order is guaranteed to '>=' min_order while min_order always '>='
> order. So current_order must be '>=' order.
>
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> ---
> mm/page_alloc.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 96b7c1a7d1f2..d37ec87515d0 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2072,8 +2072,7 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
> * allocation falls back into a different pageblock than this
> * one, it won't cause permanent fragmentation.
> */
> - if (!can_steal && start_migratetype == MIGRATE_MOVABLE
> - && current_order > order)
> + if (!can_steal && start_migratetype == MIGRATE_MOVABLE)
> goto find_smallest;

Hi,
if my analysis is correct, min_order can be initialized to the value of
order before the loop begins.

In that case, in the last loop iteration, current_order will be
equal to min_order and also to order. The condition 'current_order >
order' will evaluate to false, and the 'if' block should not be
executed?

Hugo.

\
 
 \ /
  Last update: 2023-08-08 19:31    [W:0.111 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site