Re: [PATCH 2/4] mm, compaction: more reliably increase direct compaction priority

From: Michal Hocko
Date: Wed Sep 21 2016 - 13:13:59 EST


On Tue 06-09-16 15:52:56, Vlastimil Babka wrote:
[...]
> @@ -3204,6 +3199,15 @@ should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
> if (compaction_retries <= max_retries)
> return true;
>
> + /*
> + * Make sure there is at least one attempt at the highest priority
> + * if we exhausted all retries at the lower priorities
> + */
> +check_priority:
> + if (*compact_priority > MIN_COMPACT_PRIORITY) {
> + (*compact_priority)--;
> + return true;

Don't we want to reset compaction_retries here? Otherwise we can consume
all retries on the lower priorities.

Other than that it looks good to me. With that you can add
Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> + }
> return false;
> }
> #else
--
Michal Hocko
SUSE Labs