Re: [PATCH -mm] Hook up group scheduler with control groups

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 28 Sep 2007 01:05:12 +0530
Dhaval Giani <dhaval@linux.vnet.ibm.com> wrote:

> On Thu, Sep 27, 2007 at 12:00:33PM -0700, Randy Dunlap wrote:
> > On Thu, 27 Sep 2007 23:34:15 +0530 Dhaval Giani wrote:
> > > 
> > > 
> > > +config RESOURCE_COUNTERS
> > > +	bool "Resource counters"
> > > +	help
> > > +	  This option enables controller independent resource accounting
> > 
> > Above line is tab + 2 spaces (i.e., correct).
> > 
> > > +          infrastructure that works with cgroups.
> > 
> > Above line indent is 10 spaces (i.e., not correct).
> > 
> 
> Ah! Thanks for the explanation. Corrected patch follows.
> 
> Signed-off-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
> Signed-off-by : Dhaval Giani <dhaval@linux.vnet.ibm.com>
> 
> ...
>

> @@ -219,6 +225,9 @@ static inline struct task_grp *task_grp(
>  
>  #ifdef CONFIG_FAIR_USER_SCHED
>  	tg = p->user->tg;
> +#elif CONFIG_FAIR_CGROUP_SCHED
> +	tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
> +				struct task_grp, css);
>  #else
>  	tg  = &init_task_grp;
>  #endif

that's a bit funny-looking.  Are CONFIG_FAIR_CGROUP_SCHED and
CONFIG_FAIR_USER_SCHED mutually exclusive?  Doesn't seem that way.  if
they're both defined then CONFIG_FAIR_USER_SCHED "wins".

Anyway, please confirm that this is correct?

I'll switch that to `#elif defined(CONFIG_FAIR_CGROUP_SCHED)'.  We can get
gcc warnings with `#if CONFIG_FOO', and people should be using `#ifdef
CONFIG_FOO', so I assume the same applies to #elif.