Re: [PATCH] mm: consider CMA pages in watermark check for NUMA balancing target node

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 2024/8/2 02:04, kaiyang2@cs.cmu.edu wrote:
> From: Kaiyang Zhao <kaiyang2@cs.cmu.edu>
> 
> Currently in migrate_balanced_pgdat(), ALLOC_CMA flag is not passed
> when checking watermark on the migration target node. This does not
> match the gfp in alloc_misplaced_dst_folio() which allows allocation
> from CMA.
> 
> This causes promotion failures when there are a lot of available CMA
> memory in the system.
> 
> Therefore, we change the alloc_flags passed to zone_watermark_ok() in
> migrate_balanced_pgdat().
> 
> Signed-off-by: Kaiyang Zhao <kaiyang2@cs.cmu.edu>

LGTM.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

> ---
>   mm/migrate.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 8578a930cad1..aa482c954cb0 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -2526,7 +2526,7 @@ static bool migrate_balanced_pgdat(struct pglist_data *pgdat,
>   		if (!zone_watermark_ok(zone, 0,
>   				       high_wmark_pages(zone) +
>   				       nr_migrate_pages,
> -				       ZONE_MOVABLE, 0))
> +				       ZONE_MOVABLE, ALLOC_CMA))
>   			continue;
>   		return true;
>   	}