Re: [PATCH v3 1/4] sched: cgroup SCHED_IDLE support

[Josh Don <joshdon@google.com>]

Hi Tao,

On Fri, Aug 20, 2021 at 1:38 AM Tao Zhou <tao.zhou@linux.dev> wrote:
[snip]
> >  #ifdef CONFIG_SMP
> >  extern void set_task_rq_fair(struct sched_entity *se,
> >                            struct cfs_rq *prev, struct cfs_rq *next);
> > @@ -601,6 +606,9 @@ struct cfs_rq {
> >       struct list_head        leaf_cfs_rq_list;
> >       struct task_group       *tg;    /* group that "owns" this runqueue */
> >
> > +     /* Locally cached copy of our task_group's idle value */
> > +     int                     idle;
> > +
> >  #ifdef CONFIG_CFS_BANDWIDTH
> >       int                     runtime_enabled;
> >       s64                     runtime_remaining;
> > --
> > 2.33.0.rc2.250.ged5fa647cd-goog
> >
>
> Cfs_rq and tg define @idle with int type.
> In sched_group_set_idle(..., long idle), @idle is long type.
> Use int instead.
>
> But, you filter idle value:
>
>     if (idle < 0 || idle > 1)
>         return -EINVAL;
>
> So, no effect here.. Just @idle can use 4 bytes.
>
>
>
> Thanks,
> Tao

The use of 'long'  there is because the input from the cgroup
interface is a 64 bit value.

- Josh