Re: [PATCH 2/2] drm/xe/gsc: warn about GSC stolen memory usage on RT kernels

[Maarten Lankhorst]

Hey,

On 11/4/26 04:27, Junxiao Chang wrote:
> The GSC microcontroller requires stolen memory, which can introduce
> latency spikes and negatively impact real-time performance.
> 
> Print a warning on CONFIG_PREEMPT_RT kernels to inform the user that GSC
> is active and that RT performance can be improved by disabling the GSC
> firmware (e.g., by setting the module parameter xe.gsc_firmware_path="").
> 
> Signed-off-by: Junxiao Chang <junxiao.chang@xxxxxxxxx>
> ---
>  drivers/gpu/drm/xe/xe_gsc.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gsc.c b/drivers/gpu/drm/xe/xe_gsc.c
> index aab59dc647fbd..3d06ab6fecbe0 100644
> --- a/drivers/gpu/drm/xe/xe_gsc.c
> +++ b/drivers/gpu/drm/xe/xe_gsc.c
> @@ -427,6 +427,11 @@ int xe_gsc_init(struct xe_gsc *gsc)
>  	else if (ret)
>  		goto out;
>  
> +	if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
> +		xe_gt_warn(gt, "RT performance might be impacted by GSC stolen memory usage\n");
> +		xe_gt_warn(gt, "Consider disabling GSC (xe.gsc_firmware_path=\"\") to improve it\n");
> +	}
Is this a problem on discrete as well, or only on integrated?

Kind regards,
~Maarten Lankhorst> +
>  	ret = xe_gsc_proxy_init(gsc);
>  	if (ret && ret != -ENODEV)
>  		goto out;