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

[Shakeel Butt]

On Fri, Apr 25, 2025 at 09:11:01AM +0800, Huan Yang wrote:
> 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@xxxxxxxx>
> > > > Suggested-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
> > > 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?

If that is needed in future then that can be done in future. I would say
simply call mem_cgroup_init() before cgroup_init() for now.