Re: [PATCH] sched/wait: Remove unused bit_wait_io_timeout

[Tim Chen]

On Wed, 2024-10-02 at 00:40 +0100, linux@xxxxxxxxxxx wrote:
> From: "Dr. David Alan Gilbert" <linux@xxxxxxxxxxx>
> 
> bit_wait_io_timeout has been unused since 2016's
> commit 62906027091f ("mm: add PageWaiters indicating tasks are waiting for a page bit")
> 
> Remove it.

Double check the code.  Indeed bit_wait_io_timeout() was no longer used since v4.10
and can be removed.

Reviewed-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>

> 
> Signed-off-by: Dr. David Alan Gilbert <linux@xxxxxxxxxxx>
> ---
>  include/linux/wait_bit.h |  1 -
>  kernel/sched/wait_bit.c  | 14 --------------
>  2 files changed, 15 deletions(-)
> 
> diff --git a/include/linux/wait_bit.h b/include/linux/wait_bit.h
> index 7725b7579b78..d9c23377dc75 100644
> --- a/include/linux/wait_bit.h
> +++ b/include/linux/wait_bit.h
> @@ -49,7 +49,6 @@ int wake_bit_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync
>  extern int bit_wait(struct wait_bit_key *key, int mode);
>  extern int bit_wait_io(struct wait_bit_key *key, int mode);
>  extern int bit_wait_timeout(struct wait_bit_key *key, int mode);
> -extern int bit_wait_io_timeout(struct wait_bit_key *key, int mode);
>  
>  /**
>   * wait_on_bit - wait for a bit to be cleared
> diff --git a/kernel/sched/wait_bit.c b/kernel/sched/wait_bit.c
> index 134d7112ef71..c6aab3db70bf 100644
> --- a/kernel/sched/wait_bit.c
> +++ b/kernel/sched/wait_bit.c
> @@ -228,20 +228,6 @@ __sched int bit_wait_timeout(struct wait_bit_key *word, int mode)
>  }
>  EXPORT_SYMBOL_GPL(bit_wait_timeout);
>  
> -__sched int bit_wait_io_timeout(struct wait_bit_key *word, int mode)
> -{
> -	unsigned long now = READ_ONCE(jiffies);
> -
> -	if (time_after_eq(now, word->timeout))
> -		return -EAGAIN;
> -	io_schedule_timeout(word->timeout - now);
> -	if (signal_pending_state(mode, current))
> -		return -EINTR;
> -
> -	return 0;
> -}
> -EXPORT_SYMBOL_GPL(bit_wait_io_timeout);
> -
>  void __init wait_bit_init(void)
>  {
>  	int i;