Re: [PATCH v5 4/7] drm/amdgpu: give ttm entities access to all the sdma scheds

["Christian König" <christian.koenig@amd.com>]

On 4/3/26 10:35, Pierre-Eric Pelloux-Prayer wrote:
> With this change we now have as many clear and move entities as we
> have sdma engines (limited to TTM_NUM_MOVE_FENCES).
> 
> To enable load-balancing this patch gives access to all sdma
> schedulers to all entities.
> 
> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
> Reviewed-by: Christian König <christian.koenig@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 83f6d00dc3a0..648ad344e89c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -2349,8 +2349,6 @@ void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>  		return;
>  
>  	if (enable) {
> -		struct drm_gpu_scheduler *sched;
> -
>  		if (!adev->mman.num_buffer_funcs_scheds) {
>  			dev_warn(adev->dev, "Not enabling DMA transfers for in kernel use");
>  			return;
> @@ -2358,11 +2356,10 @@ void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>  
>  		num_clear_entities = MIN(adev->mman.num_buffer_funcs_scheds, TTM_NUM_MOVE_FENCES);
>  		num_move_entities = MIN(adev->mman.num_buffer_funcs_scheds, TTM_NUM_MOVE_FENCES);
> -		sched = adev->mman.buffer_funcs_scheds[0];
>  		r = amdgpu_ttm_buffer_entity_init(&adev->mman.gtt_mgr,
>  						  &adev->mman.default_entity,
>  						  DRM_SCHED_PRIORITY_KERNEL,
> -						  &sched, 1, 0);
> +						  adev->mman.buffer_funcs_scheds, 1, 0);

Why still giving num_schedulers as 1 here???

>  		if (r < 0) {
>  			dev_err(adev->dev,
>  				"Failed setting up TTM entity (%d)\n", r);
> @@ -2380,8 +2377,11 @@ void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>  
>  		for (i = 0; i < num_clear_entities; i++) {
>  			r = amdgpu_ttm_buffer_entity_init(
> -				&adev->mman.gtt_mgr, &adev->mman.clear_entities[i],
> -				DRM_SCHED_PRIORITY_NORMAL, &sched, 1, 1);
> +				&adev->mman.gtt_mgr,
> +				&adev->mman.clear_entities[i],
> +				DRM_SCHED_PRIORITY_NORMAL,

That should be DRM_SCHED_PRIORITY_KERNEL, same below.

Regards,
Christian.

> +				adev->mman.buffer_funcs_scheds,
> +				adev->mman.num_buffer_funcs_scheds, 1);
>  
>  			if (r < 0) {
>  				for (j = 0; j < i; j++)
> @@ -2400,7 +2400,9 @@ void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>  			r = amdgpu_ttm_buffer_entity_init(
>  				&adev->mman.gtt_mgr,
>  				&adev->mman.move_entities[i],
> -				DRM_SCHED_PRIORITY_NORMAL, &sched, 1, 2);
> +				DRM_SCHED_PRIORITY_NORMAL,
> +				adev->mman.buffer_funcs_scheds,
> +				adev->mman.num_buffer_funcs_scheds, 2);
>  
>  			if (r < 0) {
>  				for (j = 0; j < i; j++)