[169/227] memcg: do not tweak node in alloc_mem_cgroup_per_node_info

Commit Message

Andrew Morton March 22, 2022, 9:47 p.m. UTC

From: Wei Yang <[e-mail]>
Subject: memcg: do not tweak node in alloc_mem_cgroup_per_node_info

alloc_mem_cgroup_per_node_info is allocated for each possible node and
this used to be a problem because !node_online nodes didn't have
appropriate data structure allocated.  This has changed by "mm: handle
uninitialized numa nodes gracefully" so we can drop the special casing
here.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Wei Yang <[e-mail]>
Signed-off-by: Michal Hocko <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Cc: Alexey Makhalov <[e-mail]>
Cc: Dennis Zhou <[e-mail]>
Cc: Eric Dumazet <[e-mail]>
Cc: Tejun Heo <[e-mail]>
Cc: Christoph Lameter <[e-mail]>
Cc: Nico Pache <[e-mail]>
Cc: Wei Yang <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: Oscar Salvador <[e-mail]>
Cc: Rafael Aquini <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/memcontrol.c |   14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

Patch

--- a/mm/memcontrol.c~memcg-do-not-tweak-node-in-alloc_mem_cgroup_per_node_info
+++ a/mm/memcontrol.c
@@ -5020,18 +5020,8 @@  struct mem_cgroup *mem_cgroup_from_id(un
 static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
 {
 	struct mem_cgroup_per_node *pn;
-	int tmp = node;
-	/*
-	 * This routine is called against possible nodes.
-	 * But it's BUG to call kmalloc() against offline node.
-	 *
-	 * TODO: this routine can waste much memory for nodes which will
-	 *       never be onlined. It's better to use memory hotplug callback
-	 *       function.
-	 */
-	if (!node_state(node, N_NORMAL_MEMORY))
-		tmp = -1;
-	pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
+
+	pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, node);
 	if (!pn)
 		return 1;