Re: [PATCH memcg v4] net: set proper memcg for net_init hooks allocations

From: Roman Gushchin
Date: Sun May 01 2022 - 17:10:09 EST



> On May 1, 2022, at 6:44 AM, Vasily Averin <vvs@xxxxxxxxxx> wrote:
>
> On 4/28/22 01:47, Shakeel Butt wrote:
>>> On Wed, Apr 27, 2022 at 3:43 PM Vasily Averin <vvs@xxxxxxxxxx> wrote:
>>>
>>> On 4/27/22 18:06, Shakeel Butt wrote:
>>>> On Wed, Apr 27, 2022 at 5:22 AM Michal Koutný <mkoutny@xxxxxxxx> wrote:
>>>>>
>>>>> On Tue, Apr 26, 2022 at 10:23:32PM -0700, Shakeel Butt <shakeelb@xxxxxxxxxx> wrote:
>>>>>> [...]
>>>>>>>
>>>>>>> +static inline struct mem_cgroup *get_mem_cgroup_from_obj(void *p)
>>>>>>> +{
>>>>>>> + struct mem_cgroup *memcg;
>>>>>>> +
>>>>>>
>>>>>> Do we need memcg_kmem_enabled() check here or maybe
>>>>>> mem_cgroup_from_obj() should be doing memcg_kmem_enabled() instead of
>>>>>> mem_cgroup_disabled() as we can have "cgroup.memory=nokmem" boot
>>>>>> param.
>>>
>>> Shakeel, unfortunately I'm not ready to answer this question right now.
>>> I even did not noticed that memcg_kmem_enabled() and mem_cgroup_disabled()
>>> have a different nature.
>>> If you have no objections I'm going to keep this place as is and investigate
>>> this question later.
>>>
>>
>> Patch is good as is. Just add the documentation to the functions in
>> the next version and you can keep the ACKs.
>
> I noticed that the kernel already has a function get_mem_cgroup_from_objcg(),
> the name of which is very similar to my new function get_mem_cgroup_from_obj().
> Maybe it's better to rename my function to get_mem_cgroup_from_ptr()?

I don’t think it’s a problem: objcg is a widely used abbreviation and in my opinion is different enough from obj. I’d keep it for the consistency with the mem_cgroup_from_obj().

Thanks!