Re: [PATCH 6/6] memcg: do not tweak node in alloc_mem_cgroup_per_node_info

[David Hildenbrand]

On 27.01.22 09:53, Michal Hocko wrote:
> From: Wei Yang <richard.weiyang@xxxxxxxxx>
> 
> alloc_mem_cgroup_per_node_info is allocated for each possible node and
> this used to be a problem because not !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.
> 
> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
> Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
>  mm/memcontrol.c | 14 ++------------
>  1 file changed, 2 insertions(+), 12 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 09d342c7cbd0..8b3f9eef4c65 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -5067,18 +5067,8 @@ struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
>  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;
>  

Acked-by: David Hildenbrand <david@xxxxxxxxxx>

-- 
Thanks,

David / dhildenb