Re: Subject: [PATCH] [PATCH] time: tick-sched: use bool for tick_stopped

[yuankuiz]

On 2018-04-10 04:00 PM, Rafael J. Wysocki wrote:
> On Tue, Apr 10, 2018 at 9:33 AM,  <yuankuiz@xxxxxxxxxxxxxx> wrote:
> > From: John Zhao <yuankuiz@xxxxxxxxxxxxxx>
> >
> > Variable tick_stopped returned by tick_nohz_tick_stopped
> > can have only true / forse values. Since the return type
> > of the tick_nohz_tick_stopped is also bool, variable
> > tick_stopped nice to have data type as bool in place of int.
> > Moreover, the executed instructions cost could be minimal
> > without potiential data type conversion.
> >
> > Signed-off-by: John Zhao <yuankuiz@xxxxxxxxxxxxxx>
> > ---
> >  kernel/time/tick-sched.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h
> > index 6de959a..4d34309 100644
> > --- a/kernel/time/tick-sched.h
> > +++ b/kernel/time/tick-sched.h
> > @@ -48,8 +48,8 @@ struct tick_sched {
> >         unsigned long                   check_clocks;
> >         enum tick_nohz_mode             nohz_mode;
> >
> > +       bool                            tick_stopped    : 1;
> >         unsigned int                    inidle          : 1;
> > -       unsigned int                    tick_stopped    : 1;
> >         unsigned int                    idle_active     : 1;
> >         unsigned int                    do_timer_last   : 1;
> >         unsigned int                    got_idle_tick   : 1;
>
> I don't think this is a good idea at all.
>
> Please see https://lkml.org/lkml/2017/11/21/384 for example.
[ZJ] Thanks for this sharing. Looks like, this patch fall into the case 
of "Maybe".

> Thanks!