On Wed, Dec 08, 2010 at 05:08:38PM -0800, Simon Kirby wrote: > On Wed, Dec 08, 2010 at 07:49:03PM -0500, Rik van Riel wrote: > > > On 12/08/2010 07:36 PM, Simon Kirby wrote: > > > >> Mel Gorman posted a similar patch to yours, but the logic is instead to > >> consider order>0 balancing sufficient when there are other balanced zones > >> totalling at least 25% of pages on this node. This would probably fix > >> your case as well. > > > > Mel's patch addresses something very different and is unlikely > > to fix the problem this patch addresses. > > Ok, I see they're quite separate. > > Johannes' patch solves the problem of trying to balance a tiny Normal > zone which happens to be full of unclaimable slab pages by giving up in > this hopeless case, regardless of order. > > Mel's patch solves the problem of fighting allocations causing an > order>0 imbalance in the small Normal zone which happens to be full of > reclaimable pages by giving up in this not-worth-bothering case. > > The key difference is that Johannes' patch has no condition on order, so > Mel's patch probably would help (though not for intended reasons) in the > order != 0 case, and probably not in the order=0 case. > I would be interested in hearing if the patch in that series that alters how sleeping_prematurely() treats zone->all_unreclaimable makes a difference though. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>