[Patch v2] drm/amdkfd: update SIMD distribution algo for GFXIP 9.4.2 onwards

[Felix Kuehling]

On 2024-02-07 23:14, Rajneesh Bhardwaj wrote:
> In certain cooperative group dispatch scenarios the default SPI resource
> allocation may cause reduced per-CU workgroup occupancy. Set
> COMPUTE_RESOURCE_LIMITS.FORCE_SIMD_DIST=1 to mitigate soft hang
> scenarions.
>
> Suggested-by: Joseph Greathouse <Joseph.Greathouse at amd.com>
> Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
> ---
> * Found a bug in the previous reviewed version
>    https://lists.freedesktop.org/archives/amd-gfx/2024-February/104101.html
>    since the q->is_gws is unset for keeping the count.
> * updated pqm_set_gws to pass minfo holding gws state for the active
>    queues and use that to apply the FORCE_SIMD_DIST_MASK.
>
>   drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c        | 4 ++++
>   drivers/gpu/drm/amd/amdkfd/kfd_priv.h                  | 1 +
>   drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c | 4 +++-
>   3 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c
> index 42d881809dc7..0b71db4c96b5 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c
> @@ -303,6 +303,10 @@ static void update_mqd(struct mqd_manager *mm, void *mqd,
>   		update_cu_mask(mm, mqd, minfo, 0);
>   	set_priority(m, q);
>   
> +	if (minfo && KFD_GC_VERSION(mm->dev) >= IP_VERSION(9, 4, 2))
> +		m->compute_resource_limits = minfo->gws ?
> +			COMPUTE_RESOURCE_LIMITS__FORCE_SIMD_DIST_MASK : 0;
> +

This looks OK because we don't set anything else in 
m->compute_resource_limits. If that ever changes, we have to be more 
careful here to not wipe out other fields in that register.


>   	q->is_active = QUEUE_IS_ACTIVE(*q);
>   }
>   
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> index 677281c0793e..f4b327a2d4a8 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> @@ -542,6 +542,7 @@ struct mqd_update_info {
>   		} cu_mask;
>   	};
>   	enum mqd_update_flag update_flag;
> +	bool gws;

Instead of adding a new bool, can we add a flag to mqd_update_flag?

Looks good to me otherwise.

Regards,
   Felix


>   };
>   
>   /**
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
> index 43eff221eae5..5416a110ced9 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
> @@ -95,6 +95,7 @@ void kfd_process_dequeue_from_device(struct kfd_process_device *pdd)
>   int pqm_set_gws(struct process_queue_manager *pqm, unsigned int qid,
>   			void *gws)
>   {
> +	struct mqd_update_info minfo = {0};
>   	struct kfd_node *dev = NULL;
>   	struct process_queue_node *pqn;
>   	struct kfd_process_device *pdd;
> @@ -146,9 +147,10 @@ int pqm_set_gws(struct process_queue_manager *pqm, unsigned int qid,
>   	}
>   
>   	pdd->qpd.num_gws = gws ? dev->adev->gds.gws_size : 0;
> +	minfo.gws = !!gws;
>   
>   	return pqn->q->device->dqm->ops.update_queue(pqn->q->device->dqm,
> -							pqn->q, NULL);
> +							pqn->q, &minfo);
>   }
>   
>   void kfd_process_dequeue_from_all_devices(struct kfd_process *p)