Re: [PATCH 3/4] soc: apple: rtkit: Use high prio work queue

[Alyssa Rosenzweig <alyssa@rosenzweig.io>]

Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>

Le Sat , Feb 22, 2025 at 04:56:48PM +0000, Sven Peter via B4 Relay a écrit :
> From: Janne Grunau <j@jannau.net>
> 
> rtkit messages as communication with the DCP firmware for framebuffer
> swaps or input events are time critical so use WQ_HIGHPRI to prevent
> user space CPU load to increase latency.
> With kwin_wayland 6's explicit sync mode user space load was able to
> delay the IOMFB rtkit communication enough to miss vsync for surface
> swaps. Minimal test scenario is constantly resizing a glxgears
> Xwayland window.
> 
> Signed-off-by: Janne Grunau <j@jannau.net>
> Signed-off-by: Sven Peter <sven@svenpeter.dev>
> ---
>  drivers/soc/apple/rtkit.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/apple/rtkit.c b/drivers/soc/apple/rtkit.c
> index 35734ae8c9ce..b7f4654c3341 100644
> --- a/drivers/soc/apple/rtkit.c
> +++ b/drivers/soc/apple/rtkit.c
> @@ -695,7 +695,7 @@ struct apple_rtkit *apple_rtkit_init(struct device *dev, void *cookie,
>  	rtk->mbox->rx = apple_rtkit_rx;
>  	rtk->mbox->cookie = rtk;
>  
> -	rtk->wq = alloc_ordered_workqueue("rtkit-%s", WQ_MEM_RECLAIM,
> +	rtk->wq = alloc_ordered_workqueue("rtkit-%s", WQ_HIGHPRI | WQ_MEM_RECLAIM,
>  					  dev_name(rtk->dev));
>  	if (!rtk->wq) {
>  		ret = -ENOMEM;
> 
> -- 
> 2.34.1
> 
>