[PATCH 8/8] drm/amdgpu: cache the fence to wait for a VMID

[Chunming Zhou]

On 2018年01月31日 23:47, Christian König wrote:
> Beneficial when a lot of processes are waiting for VMIDs.
Yeah, we can save re-creating fence array when vmid is used up.

Reviewed-by: Chunming Zhou <david1.zhou at amd.com>

>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c  | 7 +++++--
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 3 +++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 1 +
>   3 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
> index fff575fd55c0..b4526f98f0c0 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
> @@ -205,6 +205,9 @@ static int amdgpu_vmid_grab_idle(struct amdgpu_vm *vm,
>   	unsigned i;
>   	int r;
>   
> +	if (ring->vmid_wait && !dma_fence_is_signaled(ring->vmid_wait))
> +		return amdgpu_sync_fence(adev, sync, ring->vmid_wait, false);
> +
>   	fences = kmalloc_array(sizeof(void *), id_mgr->num_ids, GFP_KERNEL);
>   	if (!fences)
>   		return -ENOMEM;
> @@ -239,9 +242,9 @@ static int amdgpu_vmid_grab_idle(struct amdgpu_vm *vm,
>   		}
>   
>   		r = amdgpu_sync_fence(adev, sync, &array->base, false);
> -		dma_fence_put(&array->base);
> +		dma_fence_put(ring->vmid_wait);
> +		ring->vmid_wait = &array->base;
>   		return r;
> -
>   	}
>   	kfree(fences);
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> index 13044e66dcaf..e223b0f6417b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> @@ -360,6 +360,9 @@ void amdgpu_ring_fini(struct amdgpu_ring *ring)
>   
>   	amdgpu_debugfs_ring_fini(ring);
>   
> +	dma_fence_put(ring->vmid_wait);
> +	ring->vmid_wait = NULL;
> +
>   	ring->adev->rings[ring->idx] = NULL;
>   }
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> index 867f53332305..075976855651 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -196,6 +196,7 @@ struct amdgpu_ring {
>   	u64			cond_exe_gpu_addr;
>   	volatile u32		*cond_exe_cpu_addr;
>   	unsigned		vm_inv_eng;
> +	struct dma_fence	*vmid_wait;
>   	bool			has_compute_vm_bug;
>   
>   	atomic_t		num_jobs[DRM_SCHED_PRIORITY_MAX];