Re: [PATCH 6/7] sock, cgroup: add sock->sk_cgroup

[Tejun Heo <tj@kernel.org>]

Hello, Daniel.

On Fri, Nov 20, 2015 at 12:04:05PM +0100, Daniel Wagner wrote:
> >  static inline u16 sock_cgroup_prioidx(struct sock_cgroup_data *skcd)
> >  {
> > -	return skcd->prioidx;
> > +	return (skcd->is_data & 1) ? skcd->prioidx : 1;
> >  }
> >  
> >  static inline u32 sock_cgroup_classid(struct sock_cgroup_data *skcd)
> >  {
> > -	return skcd->classid;
> > +	return (skcd->is_data & 1) ? skcd->classid : 0;
> >  }
> 
> 
> I still try to understand what the code does, hence this stupid question:
> 
> Why is sock_cgroup_prioidx() returning 1 if is not data and
> sock_cgroup_classid() a 0?

I prolly should have added comments there.  prioidx carries the cgroup
ID on the hierarchy net_prio is attached to, so if nothing is
configured, the default value would be the ID of the root cgroup which
is always 1.  For net_cls, the unconfigured default value is zero.
Will refresh the patch with comments.

Thanks.

-- 
tejun