Re: [PATCH] tasklet: Remove tasklet_kill_immediate

[Paul E. McKenney]

On Sat, Mar 06, 2021 at 01:36:58PM -0800, Davidlohr Bueso wrote:
> Ever since RCU was converted to softirq, it has no users.
> 
> Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>

That was a long time ago...

Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxx>

> ---
>  include/linux/interrupt.h |  1 -
>  kernel/softirq.c          | 32 --------------------------------
>  2 files changed, 33 deletions(-)
> 
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 967e25767153..36a2ac6baf9a 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -712,7 +712,6 @@ static inline void tasklet_enable(struct tasklet_struct *t)
>  }
>  
>  extern void tasklet_kill(struct tasklet_struct *t);
> -extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
>  extern void tasklet_init(struct tasklet_struct *t,
>  			 void (*func)(unsigned long), unsigned long data);
>  extern void tasklet_setup(struct tasklet_struct *t,
> diff --git a/kernel/softirq.c b/kernel/softirq.c
> index 9908ec4a9bfe..8b44ab9a2f69 100644
> --- a/kernel/softirq.c
> +++ b/kernel/softirq.c
> @@ -658,38 +658,6 @@ static void run_ksoftirqd(unsigned int cpu)
>  }
>  
>  #ifdef CONFIG_HOTPLUG_CPU
> -/*
> - * tasklet_kill_immediate is called to remove a tasklet which can already be
> - * scheduled for execution on @cpu.
> - *
> - * Unlike tasklet_kill, this function removes the tasklet
> - * _immediately_, even if the tasklet is in TASKLET_STATE_SCHED state.
> - *
> - * When this function is called, @cpu must be in the CPU_DEAD state.
> - */
> -void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu)
> -{
> -	struct tasklet_struct **i;
> -
> -	BUG_ON(cpu_online(cpu));
> -	BUG_ON(test_bit(TASKLET_STATE_RUN, &t->state));
> -
> -	if (!test_bit(TASKLET_STATE_SCHED, &t->state))
> -		return;
> -
> -	/* CPU is dead, so no lock needed. */
> -	for (i = &per_cpu(tasklet_vec, cpu).head; *i; i = &(*i)->next) {
> -		if (*i == t) {
> -			*i = t->next;
> -			/* If this was the tail element, move the tail ptr */
> -			if (*i == NULL)
> -				per_cpu(tasklet_vec, cpu).tail = i;
> -			return;
> -		}
> -	}
> -	BUG();
> -}
> -
>  static int takeover_tasklets(unsigned int cpu)
>  {
>  	/* CPU is dead, so no lock needed. */
> -- 
> 2.26.2
>