Re: [PATCH 1/4] panthor: Use all available GPU cores

[Liviu Dudau <liviu.dudau@arm.com>]

On Thu, Oct 15, 2026 at 02:05:46PM +0100, Daniel Stone wrote:
> There's no reason to limit ourselves to one arbitrarily-chosen core.
> 
> Signed-off-by: Daniel Stone <daniels@collabora.com>

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

Best regards,
Liviu

> ---
>  lib/igt_panthor.c | 29 +++++++----------------------
>  lib/igt_panthor.h |  1 -
>  2 files changed, 7 insertions(+), 23 deletions(-)
> 
> diff --git a/lib/igt_panthor.c b/lib/igt_panthor.c
> index 11d8ec342..cd6b6b7fd 100644
> --- a/lib/igt_panthor.c
> +++ b/lib/igt_panthor.c
> @@ -2,6 +2,7 @@
>  // SPDX-FileCopyrightText: Copyright (C) 2025 Collabora Ltd.
>  
>  #include "drmtest.h"
> +#include "igt_aux.h"
>  #include "igt_panthor.h"
>  #include "ioctl_wrappers.h"
>  #include "panthor_drm.h"
> @@ -69,22 +70,6 @@ void igt_panthor_group_submit(int fd, struct drm_panthor_group_submit *group_sub
>  		do_ioctl(fd, DRM_IOCTL_PANTHOR_GROUP_SUBMIT, group_submit);
>  }
>  
> -/**
> - * igt_panthor_get_first_core:
> - * @cores_present: bitmask of available cores
> - *
> - * Get a mask with only the first available core bit set.
> - *
> - * Returns: core mask with first available core, or 0 if no cores available
> - */
> -uint64_t igt_panthor_get_first_core(uint64_t cores_present)
> -{
> -	if (cores_present == 0)
> -		return 0;
> -
> -	return 1ULL << (ffs(cores_present) - 1);
> -}
> -
>  /**
>   * igt_panthor_group_create_simple:
>   * @fd: device file descriptor
> @@ -109,13 +94,13 @@ uint32_t igt_panthor_group_create_simple(int fd, uint32_t vm_id, int err)
>  	queues = (struct drm_panthor_obj_array)DRM_PANTHOR_OBJ_ARRAY(1, &queue);
>  
>  	group_create.queues = queues;
> -	group_create.max_compute_cores = 1;
> -	group_create.max_fragment_cores = 1;
> -	group_create.max_tiler_cores = 1;
> +	group_create.max_compute_cores = igt_hweight(gpu_info.shader_present);
> +	group_create.max_fragment_cores = igt_hweight(gpu_info.shader_present);
> +	group_create.max_tiler_cores = igt_hweight(gpu_info.tiler_present);
>  	group_create.priority = PANTHOR_GROUP_PRIORITY_MEDIUM;
> -	group_create.compute_core_mask = igt_panthor_get_first_core(gpu_info.shader_present);
> -	group_create.fragment_core_mask = igt_panthor_get_first_core(gpu_info.shader_present);
> -	group_create.tiler_core_mask = igt_panthor_get_first_core(gpu_info.tiler_present);
> +	group_create.compute_core_mask = gpu_info.shader_present;
> +	group_create.fragment_core_mask = gpu_info.shader_present;
> +	group_create.tiler_core_mask = gpu_info.tiler_present;
>  	group_create.vm_id = vm_id;
>  
>  	igt_panthor_group_create(fd, &group_create, err);
> diff --git a/lib/igt_panthor.h b/lib/igt_panthor.h
> index ba4a9bf1e..63c4f2bf4 100644
> --- a/lib/igt_panthor.h
> +++ b/lib/igt_panthor.h
> @@ -36,7 +36,6 @@ void igt_panthor_group_submit_simple(int fd, uint32_t group_handle,
>  				     uint32_t queue_index, uint64_t stream_addr,
>  				     uint32_t stream_size, uint32_t syncobj_handle,
>  				     int err);
> -uint64_t igt_panthor_get_first_core(uint64_t cores_present);
>  
>  static inline void igt_panthor_vm_bind(int fd, uint32_t vm_id, uint32_t bo_handle,
>  				       uint64_t va, uint64_t size, uint32_t flags, int err)
> -- 
> 2.47.3
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯