drm/amdgpu: set sched_hw_submission higher for KIQ (v3)

KIQ doesn't really use the GPU scheduler.  The base
drivers generally use the KIQ ring directly rather than
submitting IBs.  However, amdgpu_sched_hw_submission
(which defaults to 2) limits the number of outstanding
fences to 2.  KFD uses the KIQ for TLB flushes and the
2 fence limit hurts performance when there are several KFD
processes running.

v2: move some expressions to one line
    change KIQ sched_hw_submission to at least 16
v3: bump to 256

Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index 6c5646b..5ce6528 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -170,6 +170,16 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
                     unsigned irq_type)
 {
        int r;
+       int sched_hw_submission = amdgpu_sched_hw_submission;
+
+       /* Set the hw submission limit higher for KIQ because
+        * it's used for a number of gfx/compute tasks by both
+        * KFD and KGD which may have outstanding fences and
+        * it doesn't really use the gpu scheduler anyway;
+        * KIQ tasks get submitted directly to the ring.
+        */
+       if (ring->funcs->type == AMDGPU_RING_TYPE_KIQ)
+               sched_hw_submission = max(sched_hw_submission, 256);
 
        if (ring->adev == NULL) {
                if (adev->num_rings >= AMDGPU_MAX_RINGS)
@@ -178,8 +188,7 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
                ring->adev = adev;
                ring->idx = adev->num_rings++;
                adev->rings[ring->idx] = ring;
-               r = amdgpu_fence_driver_init_ring(ring,
-                       amdgpu_sched_hw_submission);
+               r = amdgpu_fence_driver_init_ring(ring, sched_hw_submission);
                if (r)
                        return r;
        }
@@ -218,8 +227,7 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
                return r;
        }
 
-       ring->ring_size = roundup_pow_of_two(max_dw * 4 *
-                                            amdgpu_sched_hw_submission);
+       ring->ring_size = roundup_pow_of_two(max_dw * 4 * sched_hw_submission);
 
        ring->buf_mask = (ring->ring_size / 4) - 1;
        ring->ptr_mask = ring->funcs->support_64bit_ptrs ?