On Wed 13-02-19 14:11:31, Peter Zijlstra wrote:

On Wed, Feb 13, 2019 at 12:50:14PM +0100, Michal Hocko wrote:

quoted

On Wed 13-02-19 11:32:31, Peter Zijlstra wrote:

quoted

On Wed, Feb 13, 2019 at 10:43:15AM +0100, Michal Hocko wrote:

quoted

@@ -5259,6 +5261,11 @@ static void build_zonelists(pg_data_t *pgdat)
 
 	build_zonelists_in_node_order(pgdat, node_order, nr_nodes);
 	build_thisnode_zonelists(pgdat);
+
+	pr_info("node[%d] zonelist: ", pgdat->node_id);
+	for_each_zone_zonelist(zone, z, &pgdat->node_zonelists[ZONELIST_FALLBACK], MAX_NR_ZONES-1)
+		pr_cont("%d:%s ", zone_to_nid(zone), zone->name);
+	pr_cont("\n");
 }

Have you ran this by the SGI and other stupid large machine vendors?

I do not have such a large machine handy. The biggest I have has
handfull (say dozen) of NUMA nodes.

quoted

Traditionally they tend to want to remove such things instead of adding
them.

I do not insist on this patch but I find it handy. If there is an
opposition I will not miss it much.

Well, I don't have machines like that either and don't mind the patch.
Just raising the issue; I've had the big iron boys complain about
similar things (typically printing something for every CPU, which gets
out of hand much faster than zones, but still).

Maybe we can try to push this through and revert if somebody complains
about an excessive output.

-- 
Michal Hocko
SUSE Labs