Re: [RFC,v2,9/9] hyper_dmabuf: threaded interrupt in Xen-backend

[Oleksandr Andrushchenko]

On 02/14/2018 03:50 AM, Dongwon Kim wrote:
> Use threaded interrupt intead of regular one because most part of ISR
> is time-critical and possibly sleeps
>
> Signed-off-by: Dongwon Kim <dongwon.kim@xxxxxxxxx>
> ---
>   .../hyper_dmabuf/backends/xen/hyper_dmabuf_xen_comm.c | 19 +++++++++++--------
>   1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/dma-buf/hyper_dmabuf/backends/xen/hyper_dmabuf_xen_comm.c b/drivers/dma-buf/hyper_dmabuf/backends/xen/hyper_dmabuf_xen_comm.c
> index 30bc4b6304ac..65af5ddfb2d7 100644
> --- a/drivers/dma-buf/hyper_dmabuf/backends/xen/hyper_dmabuf_xen_comm.c
> +++ b/drivers/dma-buf/hyper_dmabuf/backends/xen/hyper_dmabuf_xen_comm.c
> @@ -332,11 +332,14 @@ int xen_be_init_tx_rbuf(int domid)
>   	}
>   
>   	/* setting up interrupt */
> -	ret = bind_evtchn_to_irqhandler(alloc_unbound.port,
> -					front_ring_isr, 0,
> -					NULL, (void *) ring_info);
> +	ring_info->irq = bind_evtchn_to_irq(alloc_unbound.port);
>   
> -	if (ret < 0) {
> +	ret = request_threaded_irq(ring_info->irq,
> +				   NULL,
> +				   front_ring_isr,
> +				   IRQF_ONESHOT, NULL, ring_info);
> +
Why don't you go with threaded IRQ from the beginning and change it
in the patch #9?
> +	if (ret != 0) {
>   		dev_err(hy_drv_priv->dev,
>   			"Failed to setup event channel\n");
>   		close.port = alloc_unbound.port;
> @@ -348,7 +351,6 @@ int xen_be_init_tx_rbuf(int domid)
>   	}
>   
>   	ring_info->rdomain = domid;
> -	ring_info->irq = ret;
>   	ring_info->port = alloc_unbound.port;
>   
>   	mutex_init(&ring_info->lock);
> @@ -535,9 +537,10 @@ int xen_be_init_rx_rbuf(int domid)
>   	if (!xen_comm_find_tx_ring(domid))
>   		ret = xen_be_init_tx_rbuf(domid);
>   
> -	ret = request_irq(ring_info->irq,
> -			  back_ring_isr, 0,
> -			  NULL, (void *)ring_info);
> +	ret = request_threaded_irq(ring_info->irq,
> +				   NULL,
> +				   back_ring_isr, IRQF_ONESHOT,
> +				   NULL, (void *)ring_info);
>   
Ditto
>   	return ret;
>