Re: [PATCH v3 2/4] sched: Introduce migratable()

Sebastian Andrzej Siewior
2021-08-17T14:43:54Z

On 2021-08-11 21:13:52 [+0100], Valentin Schneider wrote:
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index debc960f41e3..8ba7b4a7ee69 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1715,6 +1715,16 @@ static inline bool is_percpu_thread(void)
> #endif
> }
>
> +/* Is the current task guaranteed to stay on its current CPU? */
> +static inline bool migratable(void)
> +{
> +#ifdef CONFIG_SMP
> + return preemptible() && !current->migration_disabled;
> +#else
> + return true;

shouldn't this be false in the UP case?

> +#endif
> +}
> +
> /* Per-process atomic flags. */
> #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
> #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */

Sebastian