Re: [PATCH rcu 1/2] torture: Add a kthread-creation callback to _torture_create_kthread()

[Joel Fernandes]

On Thu, Jul 27, 2023 at 11:22 PM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:
>
> This commit adds a kthread-creation callback to the
> _torture_create_kthread() function, which allows callers of a new
> torture_create_kthread_cb() macro to specify a function to be invoked
> after the kthread is created but before it is awakened for the first time.
>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
> Cc: John Stultz <jstultz@xxxxxxxxxx>
> Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
> Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx>

Reviewed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>

thanks,

 - Joel


> Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
> Cc: Valentin Schneider <vschneid@xxxxxxxxxx>
> Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
> Cc: kernel-team@xxxxxxxxxxx
> ---
>  include/linux/torture.h | 7 +++++--
>  kernel/torture.c        | 6 +++++-
>  2 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/torture.h b/include/linux/torture.h
> index 7038104463e4..bb466eec01e4 100644
> --- a/include/linux/torture.h
> +++ b/include/linux/torture.h
> @@ -108,12 +108,15 @@ bool torture_must_stop(void);
>  bool torture_must_stop_irq(void);
>  void torture_kthread_stopping(char *title);
>  int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
> -                            char *f, struct task_struct **tp);
> +                            char *f, struct task_struct **tp, void (*cbf)(struct task_struct *tp));
>  void _torture_stop_kthread(char *m, struct task_struct **tp);
>
>  #define torture_create_kthread(n, arg, tp) \
>         _torture_create_kthread(n, (arg), #n, "Creating " #n " task", \
> -                               "Failed to create " #n, &(tp))
> +                               "Failed to create " #n, &(tp), NULL)
> +#define torture_create_kthread_cb(n, arg, tp, cbf) \
> +       _torture_create_kthread(n, (arg), #n, "Creating " #n " task", \
> +                               "Failed to create " #n, &(tp), cbf)
>  #define torture_stop_kthread(n, tp) \
>         _torture_stop_kthread("Stopping " #n " task", &(tp))
>
> diff --git a/kernel/torture.c b/kernel/torture.c
> index 8be83fdc6be1..b88a1a86d9da 100644
> --- a/kernel/torture.c
> +++ b/kernel/torture.c
> @@ -932,7 +932,7 @@ EXPORT_SYMBOL_GPL(torture_kthread_stopping);
>   * it starts, you will need to open-code your own.
>   */
>  int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
> -                           char *f, struct task_struct **tp)
> +                           char *f, struct task_struct **tp, void (*cbf)(struct task_struct *tp))
>  {
>         int ret = 0;
>
> @@ -944,6 +944,10 @@ int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
>                 *tp = NULL;
>                 return ret;
>         }
> +
> +       if (cbf)
> +               cbf(*tp);
> +
>         wake_up_process(*tp);  // Process is sleeping, so ordering provided.
>         torture_shuffle_task_register(*tp);
>         return ret;
> --
> 2.40.1
>