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

[Rafael J. Wysocki]

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.

Thanks!