Re: [PATCH v3 02/21] memcg: make mm_match_cgroup() hirarchical

[Konstantin Khlebnikov]

KAMEZAWA Hiroyuki wrote:
> On Thu, 23 Feb 2012 17:51:46 +0400
> Konstantin Khlebnikov<khlebnikov@xxxxxxxxxx>  wrote:
>
> > Check mm-owner cgroup membership hierarchically.
> >
> > Signed-off-by: Konstantin Khlebnikov<khlebnikov@xxxxxxxxxx>
>
>
> Ack. but ... see below.
>
> > ---
> >   include/linux/memcontrol.h |   11 ++---------
> >   mm/memcontrol.c            |   20 ++++++++++++++++++++
> >   2 files changed, 22 insertions(+), 9 deletions(-)
> >
> > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> > index 8c4d74f..4822d53 100644
> > --- a/include/linux/memcontrol.h
> > +++ b/include/linux/memcontrol.h
> > @@ -87,15 +87,8 @@ extern struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm);
> >   extern struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg);
> >   extern struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont);
> >
> > -static inline
> > -int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
> > -{
> > -	struct mem_cgroup *memcg;
> > -	rcu_read_lock();
> > -	memcg = mem_cgroup_from_task(rcu_dereference((mm)->owner));
> > -	rcu_read_unlock();
> > -	return cgroup == memcg;
> > -}
> > +extern int mm_match_cgroup(const struct mm_struct *mm,
> > +			   const struct mem_cgroup *cgroup);
> >
> >   extern struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg);
> >
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index b8039d2..77f5d48 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -821,6 +821,26 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
> >   				struct mem_cgroup, css);
> >   }
> >
> > +/**
> > + * mm_match_cgroup - cgroup hierarchy mm membership test
> > + * @mm		mm_struct to test
> > + * @cgroup	target cgroup
> > + *
> > + * Returns true if mm belong this cgroup or any its child in hierarchy
>
> belongs to ?
>
> > + */
> > +int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
> > +{
>
> Please use "memcg" for representing "memory cgroup" (other function's arguments uses "memcg")
>
> > +	struct mem_cgroup *memcg;
>
> So, rename this as *cur_memcg or some.
>
> > +
> > +	rcu_read_lock();
> > +	memcg = mem_cgroup_from_task(rcu_dereference((mm)->owner));
> > +	while (memcg != cgroup&&  memcg&&  memcg->use_hierarchy)
> > +		memcg = parent_mem_cgroup(memcg);
>
> IIUC, parent_mem_cgroup() checks mem->res.parent. mem->res.parent is set only when
> parent->use_hierarchy == true. Then,
>
> 	while (memcg != cgroup)
> 		memcg = parent_mem_cgroup(memcg);
>
> will be enough.

Here will be mem_cgroup_same_or_subtree(), see reply from Johannes Weiner.

> Thanks,
> -Kame

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/