Re: [PATCH 5/7] mm/page_alloc.c: Allow __GFP_NOFAIL requests deeper access to reserves

[Vlastimil Babka]

On 1/9/23 16:16, Mel Gorman wrote:
> Currently __GFP_NOFAIL allocations without any other flags can access 25%
> of the reserves but these requests imply that the system cannot make forward
> progress until the allocation succeeds. Allow __GFP_NOFAIL access to 75%
> of the min reserve.
> 
> Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

> ---
>  mm/page_alloc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 6f41b84a97ac..d2df78f5baa2 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5308,7 +5308,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
>  		 * could deplete whole memory reserves which would just make
>  		 * the situation worse
>  		 */
> -		page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac);
> +		page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_MIN_RESERVE|ALLOC_HARDER, ac);
>  		if (page)
>  			goto got_pg;
>