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

[David Hildenbrand <david@redhat.com>]

On 31.01.20 13:09, Kirill Tkhai wrote:
> Despite shrinker_map may be touched from any cpu
> (e.g., a bit there may be set by a task running
> everywhere); kswapd is always bound to specific
> node. So, we will allocate shrinker_map from
> related NUMA node to respect its NUMA locality.
> Also, this follows generic way we use for allocation
> memcg's per-node data.
> 
> Two hunks node_state() patterns are borrowed from
> alloc_mem_cgroup_per_node_info().
> 
> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
> ---
>  mm/memcontrol.c |   13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 6f6dc8712e39..8ccc8ceb1b17 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -323,7 +323,7 @@ static int memcg_expand_one_shrinker_map(struct mem_cgroup *memcg,
>  					 int size, int old_size)
>  {
>  	struct memcg_shrinker_map *new, *old;
> -	int nid;
> +	int nid, tmp;
>  
>  	lockdep_assert_held(&memcg_shrinker_map_mutex);
>  
> @@ -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 : - 1;
> +		new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, tmp);
>  		if (!new)
>  			return -ENOMEM;
>  
> @@ -370,7 +371,7 @@ static void memcg_free_shrinker_maps(struct mem_cgroup *memcg)
>  static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg)
>  {
>  	struct memcg_shrinker_map *map;
> -	int nid, size, ret = 0;
> +	int nid, size, tmp, ret = 0;
>  
>  	if (mem_cgroup_is_root(memcg))
>  		return 0;
> @@ -378,7 +379,9 @@ static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg)
>  	mutex_lock(&memcg_shrinker_map_mutex);
>  	size = memcg_shrinker_map_size;
>  	for_each_node(nid) {
> -		map = kvzalloc(sizeof(*map) + size, GFP_KERNEL);
> +		/* See comment in alloc_mem_cgroup_per_node_info()*/
> +		tmp = node_state(nid, N_NORMAL_MEMORY) ? nid : - 1;
> +		map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, tmp);
>  		if (!map) {
>  			memcg_free_shrinker_maps(memcg);
>  			ret = -ENOMEM;
> 

I think it is preferred to use NUMA_NO_NODE instead of -1.


-- 
Thanks,

David / dhildenb