Re: [PATCH 21/27] mm, vmscan: Only wakeup kswapd once per node for the requested classzone

[Vlastimil Babka]

On 06/21/2016 04:16 PM, Mel Gorman wrote:
> kswapd is woken when zones are below the low watermark but the wakeup
> decision is not taking the classzone into account.  Now that reclaim is
> node-based, it is only required to wake kswapd once per node and only if
> all zones are unbalanced for the requested classzone.
>
> Note that one node might be checked multiple times if the zonelist is ordered
> by node because there is no cheap way of tracking what nodes have already
> been visited. For zone-ordering, each node should be checked only once.
>
> Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>