Re: [PATCH v2 26/28] mm: memcontrol: refactor memcg_reparent_objcgs()

[Qi Zheng]

On 12/18/25 9:45 PM, Johannes Weiner wrote:
> On Wed, Dec 17, 2025 at 03:27:50PM +0800, Qi Zheng wrote:
> > +static void memcg_reparent_objcgs(struct mem_cgroup *src)
> > +{
> > +	struct obj_cgroup *objcg = rcu_dereference_protected(src->objcg, true);
> > +	struct mem_cgroup *dst = parent_mem_cgroup(src);
> > +
> > +	reparent_locks(src, dst);
> > +
> > +	__memcg_reparent_objcgs(src, dst);
>
> Please have __memcg_reparent_objcgs() return the dead objcg for the
> percpu_ref_kill(), instead of doing the deref twice.

OK, will do.

> And please use @child, @parent (or @memcg, @parent) throughout instead
> of @src and @dst.

OK.

> > +
> > +	reparent_unlocks(src, dst);
> >   
> >   	percpu_ref_kill(&objcg->refcnt);
>
> With that,
>
> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Thanks!