On Tue 18-02-14 17:43:38, David Rientjes wrote: > On Tue, 18 Feb 2014, Nishanth Aravamudan wrote: > > > How about the following? > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index 5de4337..1a0eced 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -1854,7 +1854,8 @@ static void __paginginit init_zone_allows_reclaim(int nid) > > int i; > > > > for_each_online_node(i) > > - if (node_distance(nid, i) <= RECLAIM_DISTANCE) > > + if (node_distance(nid, i) <= RECLAIM_DISTANCE || > > + !NODE_DATA(i)->node_present_pages) > > node_set(i, NODE_DATA(nid)->reclaim_nodes); > > else > > zone_reclaim_mode = 1; > > [ I changed the above from NODE_DATA(nid) -> NODE_DATA(i) as you caught > so we're looking at the right code. ] > > That can't be right, it would allow reclaiming from a memoryless node. I > think what you want is > > for_each_online_node(i) { > if (!node_present_pages(i)) > continue; > if (node_distance(nid, i) <= RECLAIM_DISTANCE) { > node_set(i, NODE_DATA(nid)->reclaim_nodes); > continue; > } > /* Always try to reclaim locally */ > zone_reclaim_mode = 1; > } > > but we really should be able to do for_each_node_state(i, N_MEMORY) here > and memoryless nodes should already be excluded from that mask. Agreed! Actually the code I am currently interested in is based on 3.0 kernel where zone_reclaim_mode is set in build_zonelists which relies on find_next_best_node which iterates only N_HIGH_MEMORY nodes which should have non 0 present pages. [...] -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>