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

From: Vlastimil Babka
Date: Thu Sep 22 2016 - 08:51:57 EST


On 09/21/2016 07:13 PM, Michal Hocko wrote:
> 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.

Good point, patch-fix below.

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

Thanks!

>> + }
>> return false;
>> }
>> #else
>

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