[PATCH 2/7] drm/amdgpu: use scheduler load balancing for SDMA CS

[Zhang, Jerry (Junwei)]

On 08/01/2018 07:31 PM, Christian König wrote:
> Start to use the scheduler load balancing for userspace SDMA
> command submissions.
>

In this case, each SDMA could load all SDMA(instances) rqs, and UMD will not specify a ring id.
If so, we may abstract a set of rings for each type of IP, associated with such kind of IP instances' rq.
Accordingly libdrm needs to update as well, but it may be more user-friendly, regardless of ring id when submits command.

And will it interfere ctx->ring's settings, like sequence?
e.g. submit a command to SDMA0, but SDMA0 is busy and SDMA1 is idle,
So the command will be pushed to SDMA1 rq, but update sequence for ctx->ring[SDMA0] actually.


Regards,
Jerry

> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 25 +++++++++++++++++++++----
>   1 file changed, 21 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> index df6965761046..59046f68975a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> @@ -48,7 +48,8 @@ static int amdgpu_ctx_init(struct amdgpu_device *adev,
>   			   struct drm_file *filp,
>   			   struct amdgpu_ctx *ctx)
>   {
> -	unsigned i, j;
> +	struct drm_sched_rq *sdma_rqs[AMDGPU_MAX_RINGS];
> +	unsigned i, j, num_sdma_rqs;
>   	int r;
>
>   	if (priority < 0 || priority >= DRM_SCHED_PRIORITY_MAX)
> @@ -80,18 +81,34 @@ static int amdgpu_ctx_init(struct amdgpu_device *adev,
>   	ctx->init_priority = priority;
>   	ctx->override_priority = DRM_SCHED_PRIORITY_UNSET;
>
> -	/* create context entity for each ring */
> +	num_sdma_rqs = 0;
>   	for (i = 0; i < adev->num_rings; i++) {
>   		struct amdgpu_ring *ring = adev->rings[i];
>   		struct drm_sched_rq *rq;
>
>   		rq = &ring->sched.sched_rq[priority];
> +		if (ring->funcs->type == AMDGPU_RING_TYPE_SDMA)
> +			sdma_rqs[num_sdma_rqs++] = rq;
> +	}
> +
> +	/* create context entity for each ring */
> +	for (i = 0; i < adev->num_rings; i++) {
> +		struct amdgpu_ring *ring = adev->rings[i];
>
>   		if (ring == &adev->gfx.kiq.ring)
>   			continue;
>
> -		r = drm_sched_entity_init(&ctx->rings[i].entity,
> -					  &rq, 1, &ctx->guilty);
> +		if (ring->funcs->type == AMDGPU_RING_TYPE_SDMA) {
> +			r = drm_sched_entity_init(&ctx->rings[i].entity,
> +						  sdma_rqs, num_sdma_rqs,
> +						  &ctx->guilty);
> +		} else {
> +			struct drm_sched_rq *rq;
> +
> +			rq = &ring->sched.sched_rq[priority];
> +			r = drm_sched_entity_init(&ctx->rings[i].entity,
> +						  &rq, 1, &ctx->guilty);
> +		}
>   		if (r)
>   			goto failed;
>   	}
>