+ mm-memory_hotplug-remove-explicit-build_all_zonelists-from-try_online_node.patch added to -mm tree

+ mm-memory_hotplug-remove-explicit-build_all_zonelists-from-try_online_node.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm, memory_hotplug: remove explicit build_all_zonelists from try_online_node
has been added to the -mm tree.  Its filename is
     mm-memory_hotplug-remove-explicit-build_all_zonelists-from-try_online_node.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-memory_hotplug-remove-explicit-build_all_zonelists-from-try_online_node.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-memory_hotplug-remove-explicit-build_all_zonelists-from-try_online_node.patch

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------------------------------------------------------
From: Michal Hocko <mhocko@suse.com>
Subject: mm, memory_hotplug: remove explicit build_all_zonelists from try_online_node

try_online_node calls hotadd_new_pgdat which already calls
build_all_zonelists.  So the additional call is redundant.  Even though
hotadd_new_pgdat will only initialize zonelists of the new node this is
the right thing to do because such a node doesn't have any memory so other
zonelists would ignore all the zones from this node anyway.

Link: http://lkml.kernel.org/r/20170721143915.14161-6-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memory_hotplug.c |    7 -------
 1 file changed, 7 deletions(-)

diff -puN mm/memory_hotplug.c~mm-memory_hotplug-remove-explicit-build_all_zonelists-from-try_online_node mm/memory_hotplug.c
--- a/mm/memory_hotplug.c~mm-memory_hotplug-remove-explicit-build_all_zonelists-from-try_online_node
+++ a/mm/memory_hotplug.c
@@ -1085,13 +1085,6 @@ int try_online_node(int nid)
 	node_set_online(nid);
 	ret = register_one_node(nid);
 	BUG_ON(ret);
-
-	if (pgdat->node_zonelists->_zonerefs->zone == NULL) {
-		mutex_lock(&zonelists_mutex);
-		build_all_zonelists(NULL);
-		mutex_unlock(&zonelists_mutex);
-	}