Re: [PATCH 01/11] mm/page_isolation: prefer the node of the source page

From: Roman Gushchin
Date: Wed May 20 2020 - 20:38:40 EST


On Mon, May 18, 2020 at 10:20:47AM +0900, js1304@xxxxxxxxx wrote:
> From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
>
> For locality, it's better to migrate the page to the same node
> rather than the node of the current caller's cpu.
>
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

Acked-by: Roman Gushchin <guro@xxxxxx>

> ---
> mm/page_isolation.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/page_isolation.c b/mm/page_isolation.c
> index 2c11a38..7df89bd 100644
> --- a/mm/page_isolation.c
> +++ b/mm/page_isolation.c
> @@ -300,5 +300,7 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
>
> struct page *alloc_migrate_target(struct page *page, unsigned long private)
> {
> - return new_page_nodemask(page, numa_node_id(), &node_states[N_MEMORY]);
> + int nid = page_to_nid(page);
> +
> + return new_page_nodemask(page, nid, &node_states[N_MEMORY]);

Why not new_page_nodemask(page, page_to_nid(page), &node_states[N_MEMORY]) ?
Still fits into 80 characters.