Commit 9c608dbe authored Feb 11, 2015 by Johannes Weiner Committed by Linus Torvalds Feb 11, 2015

mm: memcontrol: simplify soft limit tree init code



- No need to test the node for N_MEMORY.  node_online() is enough for
  node fallback to work in slab, use NUMA_NO_NODE for everything else.

- Remove the BUG_ON() for allocation failure.  A NULL pointer crash is
  just as descriptive, and the absent return value check is obvious.

- Move local variables to the inner-most blocks.

- Point to the tree structure after its initialized, not before, it's
  just more logical that way.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 94737a85

mm/memcontrol.c

+8 −9

Original line number	Diff line number	Diff line
		@@ -4509,24 +4509,23 @@ EXPORT_SYMBOL(parent_mem_cgroup);

		static void __init mem_cgroup_soft_limit_tree_init(void)
		{
		struct mem_cgroup_tree_per_node *rtpn;
		struct mem_cgroup_tree_per_zone *rtpz;
		int tmp, node, zone;
		int node;

		for_each_node(node) {
		tmp = node;
		if (!node_state(node, N_NORMAL_MEMORY))
		tmp = -1;
		rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
		BUG_ON(!rtpn);
		struct mem_cgroup_tree_per_node *rtpn;
		int zone;

		soft_limit_tree.rb_tree_per_node[node] = rtpn;
		rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL,
		node_online(node) ? node : NUMA_NO_NODE);

		for (zone = 0; zone < MAX_NR_ZONES; zone++) {
		struct mem_cgroup_tree_per_zone *rtpz;

		rtpz = &rtpn->rb_tree_per_zone[zone];
		rtpz->rb_root = RB_ROOT;
		spin_lock_init(&rtpz->lock);
		}
		soft_limit_tree.rb_tree_per_node[node] = rtpn;
		}
		}

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