[igt-dev] [Intel-gfx] [PATCH i-g-t] intel_gpu_top: Don't show client header if no kernel support

[Petri Latvala]

On Fri, May 27, 2022 at 08:53:04AM +0100, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> On kernels without support for the feature we should skip showing the
> clients header to avoid confusing users.
> 
> Simply briefly open a render node to the selected device during init and
> look if the relevant fields are present in the fdinfo data.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Issue: https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/issues/120
> ---
>  tools/intel_gpu_top.c | 22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c
> index 1984c10dca29..26986a822bb7 100644
> --- a/tools/intel_gpu_top.c
> +++ b/tools/intel_gpu_top.c
> @@ -2389,6 +2389,23 @@ static void process_stdin(unsigned int timeout_us)
>  		process_normal_stdin();
>  }
>  
> +static bool has_drm_fdinfo(const struct igt_device_card *card)
> +{
> +	struct drm_client_fdinfo info;
> +	unsigned int cnt;
> +	int fd;
> +
> +	fd = open(card->render, O_RDWR);
> +	if (fd < 0)
> +		return false;
> +
> +	cnt = igt_parse_drm_fdinfo(fd, &info);
> +
> +	close(fd);
> +
> +	return cnt > 0;
> +}
> +
>  static void show_help_screen(void)
>  {
>  	printf(
> @@ -2545,8 +2562,9 @@ int main(int argc, char **argv)
>  
>  	ret = EXIT_SUCCESS;
>  
> -	clients = init_clients(card.pci_slot_name[0] ?
> -			       card.pci_slot_name : IGPU_PCI);
> +	if (has_drm_fdinfo(&card))
> +		clients = init_clients(card.pci_slot_name[0] ?
> +				       card.pci_slot_name : IGPU_PCI);

Checked all usage of 'clients' below this, and everything handles NULL
properly.

That said, nothing seems to free() it, am I reading that correctly?

Anyway, that can be left for another patch, this change is
Reviewed-by: Petri Latvala <petri.latvala at intel.com>


>  	init_engine_classes(engines);
>  	if (clients) {
>  		clients->num_classes = engines->num_classes;
> -- 
> 2.32.0
>