Re: [PATCH resend 1/6] delay: add poll_event_interruptible

[Bart Van Assche]

On Fri, 2018-01-26 at 17:58 +0100, Michal Suchanek wrote:
> Add convenience macro for polling an event that does not have a
> waitqueue.
> 
> Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
> ---
>  include/linux/delay.h | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/include/linux/delay.h b/include/linux/delay.h
> index b78bab4395d8..3ae9fa395628 100644
> --- a/include/linux/delay.h
> +++ b/include/linux/delay.h
> @@ -64,4 +64,16 @@ static inline void ssleep(unsigned int seconds)
>  	msleep(seconds * 1000);
>  }
>  
> +#define poll_event_interruptible(event, interval) ({ \
> +	int ret = 0; \
> +	while (!(event)) { \
> +		if (signal_pending(current)) { \
> +			ret = -ERESTARTSYS; \
> +			break; \
> +		} \
> +		msleep_interruptible(interval); \
> +	} \
> +	ret; \
> +})
> +
>  #endif /* defined(_LINUX_DELAY_H) */

Sorry but I'm not sure we should encourage other kernel developers to use
busy-waiting by adding the poll_event_interruptible() macro to a system-wide
header file. Can that macro be moved into a CDROM-specific .c or .h file?

Thanks,

Bart.