Re: [PATCH 06/27] mm, vmscan: Make kswapd reclaim in terms of nodes

From: Mel Gorman
Date: Tue Jun 14 2016 - 10:53:09 EST


On Sun, Jun 12, 2016 at 05:33:24PM +0800, Hillf Danton wrote:
> > - /*
> > - * We put equal pressure on every zone, unless one zone has way too
> > - * many pages free already. The "too many pages" is defined as the
> > - * high wmark plus a "gap" where the gap is either the low
> > - * watermark or 1% of the zone, whichever is smaller.
> > - */
> > - balance_gap = min(low_wmark_pages(zone), DIV_ROUND_UP(
> > - zone->managed_pages, KSWAPD_ZONE_BALANCE_GAP_RATIO));
> > + nr_to_reclaim += max(high_wmark_pages(zone), SWAP_CLUSTER_MAX);
> > + }
>
> Missing sc->nr_to_reclaim = nr_to_reclaim; ?
>

Yes. It may explain why I saw lower than expected kswapd in more
detailed tests recently. Thanks.

--
Mel Gorman
SUSE Labs