Re: [Intel-gfx] [PATCH v3] drm/i915: Don't show engine information in fdinfo with GuC submission

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

On 15/04/2022 01:25, Ashutosh Dixit wrote:
> At present i915 does not fetch busyness information from GuC, resulting in
> incorrect busyness values in fdinfo. Because engine information is coupled
> with busyness in fdinfo, skip showing client engine information in fdinfo
> with GuC submission till fetching busyness is supported in the i915 GuC
> submission backend.
> 
> v2 (Daniele):
>    Make commit title and description more precise
>    Add FIXME with brief description at code change
>    s/intel_guc_submission_is_used/intel_uc_uses_guc_submission/
> 
> v3 (Daniele):
>    Drop FIXME in comment
> 
> Bug: https://gitlab.freedesktop.org/drm/intel/-/issues/5564
> Fixes: 055634e4b62f ("drm/i915: Expose client engine utilisation via fdinfo")
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com
> Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
> Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> ---
>   drivers/gpu/drm/i915/i915_drm_client.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drm_client.c b/drivers/gpu/drm/i915/i915_drm_client.c
> index e539f6b23060..475a6f824cad 100644
> --- a/drivers/gpu/drm/i915/i915_drm_client.c
> +++ b/drivers/gpu/drm/i915/i915_drm_client.c
> @@ -145,7 +145,11 @@ void i915_drm_client_fdinfo(struct seq_file *m, struct file *f)
>   		   PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
>   	seq_printf(m, "drm-client-id:\t%u\n", client->id);
>   
> -	if (GRAPHICS_VER(i915) < 8)
> +	/*
> +	 * Temporarily skip showing client engine information with GuC submission till
> +	 * fetching engine busyness is implemented in the GuC submission backend
> +	 */
> +	if (GRAPHICS_VER(i915) < 8 || intel_uc_uses_guc_submission(&i915->gt0.uc))
>   		return;
>   
>   	for (i = 0; i < ARRAY_SIZE(uabi_class_names); i++)

Thanks for fixing this while I was away. It was a simple miss, nothing 
sinister. In terms of mention of "garbage" numbers being reported - were 
they actually garbage or simply always zero?

Regards,

Tvrtko