Re: [PATCH v2] mm: Allocate shrinker_map on appropriate NUMA node

Michal Hocko
2020-01-31T15:47:40Z

On Fri 31-01-20 18:00:51, Kirill Tkhai wrote:
[...]
> @@ -333,8 +333,9 @@ static int memcg_expand_one_shrinker_map(struct mem_cgroup *memcg,
> /* Not yet online memcg */
> if (!old)
> return 0;
> -
> - new = kvmalloc(sizeof(*new) + size, GFP_KERNEL);
> + /* See comment in alloc_mem_cgroup_per_node_info()*/
> + tmp = node_state(nid, N_NORMAL_MEMORY) ? nid : NUMA_NO_NODE;
> + new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, tmp);
> if (!new)
> return -ENOMEM;

I do not think this is a good pattern to copy. Why cannot you simply use
kvmalloc_node with the given node? The allocator should fallback to the
closest node if the given one doesn't have any memory.
--
Michal Hocko
SUSE Labs