On Tue, Feb 23, 2016 at 03:04:30PM +0000, Mel Gorman wrote: > kswapd checks all eligible zones to see if they need balancing even if it was > woken for a lower zone. This made sense when we reclaimed on a per-zone basis > because we wanted to shrink zones fairly so avoid age-inversion problems. > Ideally this is completely unnecessary when reclaiming on a per-node basis. > In theory, there may still be anomalies when all requests are for lower > zones and very old pages are preserved in higher zones but this should be > the exceptional case. > > Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Johannes Weiner <[email protected]> As I mentioned in the other subthread, this should probably be fine, although it would be good, generally, to have some sort of statistics on how much of the age-distorting reclaim is happening, and then maybe mention its existence in the changelog of this patch. Just an idea.
