Subject: Re: [PATCH] mm: vmscan: do not throttle based on pfmemalloc reserves if node has no reclaimable zones

From: Dave Hansen <[email-masked]>
Date: Fri, 27 Mar 2015 13:17:59 -0700

On 03/27/2015 12:28 PM, Nishanth Aravamudan wrote:
> @@ -2585,7 +2585,7 @@ static bool pfmemalloc_watermark_ok(pg_data_t *pgdat)
>  
>         for (i = 0; i <= ZONE_NORMAL; i++) {
>                 zone = &pgdat->node_zones[i];
> -               if (!populated_zone(zone))
> +               if (!populated_zone(zone) || !zone_reclaimable(zone))
>                         continue;
>  
>                 pfmemalloc_reserve += min_wmark_pages(zone);

Do you really want zone_reclaimable()?  Or do you want something more
direct like "zone_reclaimable_pages(zone) == 0"?