Re: [PATCH v2 3/3] mm/memcg: introduce mem_cgroup_early_init

[Huan Yang <link@vivo.com>]

Hi Shakeel

在 2025/4/25 07:00, Shakeel Butt 写道:
> On Thu, Apr 24, 2025 at 09:00:01AM -0700, Shakeel Butt wrote:
>> On Thu, Apr 24, 2025 at 08:09:29PM +0800, Huan Yang wrote:
>>> When cgroup_init() creates root_mem_cgroup through css_online callback,
>>> some critical resources might not be fully initialized, forcing later
>>> operations to perform conditional checks for resource availability.
>>>
>>> This patch introduces mem_cgroup_early_init() to address the init order,
>>> it invoke before cgroup_init, so, compare mem_cgroup_init which invoked
>>> by initcall, mem_cgroup_early_init can use to prepare some key resources
>>> before root_mem_cgroup alloc.
>>>
>>> Signed-off-by: Huan Yang <link@vivo.com>
>>> Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
>> Please move this patch as the first patch of the series and also remove
>> the "early" from the function name as it has a different meaning in the
>> context of cgroup init. Something like either memcg_init() or
>> memcg_kmem_caches_init().
> BTW I think just putting this kmem cache creation in mem_cgroup_init()
> and explicitly calling it before cgroup_init() would be fine. In that
> case there would be a single memcg init function.

Maybe someone also need init something after cgroup init done?

Currently no, but for furture may need?

So, memcg_init then cgroup_init then initcall->mem_cgroup_init.

Thanks,

Huan