Re: [PATCH 2/2] mm/cgroup: delay soft limit data allocation

[Laurent Dufour]

On 22/02/2017 18:11, Michal Hocko wrote:
> On Wed 22-02-17 16:58:11, Laurent Dufour wrote:
> [...]
>>  static struct mem_cgroup_tree_per_node *
>>  soft_limit_tree_node(int nid)
>>  {
>> @@ -465,6 +497,8 @@ static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
>>  	struct mem_cgroup_tree_per_node *mctz;
>>  
>>  	mctz = soft_limit_tree_from_page(page);
>> +	if (!mctz)
>> +		return;
>>  	/*
>>  	 * Necessary to update all ancestors when hierarchy is used.
>>  	 * because their event counter is not touched.
>> @@ -502,7 +536,8 @@ static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
>>  	for_each_node(nid) {
>>  		mz = mem_cgroup_nodeinfo(memcg, nid);
>>  		mctz = soft_limit_tree_node(nid);
>> -		mem_cgroup_remove_exceeded(mz, mctz);
>> +		if (mctz)
>> +			mem_cgroup_remove_exceeded(mz, mctz);
>>  	}
>>  }
>>  
> 
> this belongs to the previous patch, right?

It may. I made the first patch fixing the panic I saw but if you prefer
this to be part of the first one, fair enough.
Tell me what you like.