NAK, it is intentionally done like this to avoid starvation of processes.
In other words we assign a VMID only when there is at least one free.
Regards,
Christian.
Am 10.05.2017 um 09:31 schrieb Chunming Zhou:
> Change-Id: If24a62b9c3097c9b040225ab0e768145b7a3db1e
> Signed-off-by: Chunming Zhou <David1.Zhou at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 92 +++++++++++++++++-----------------
> 1 file changed, 47 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index bbb3587..6259608 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -492,51 +492,6 @@ int amdgpu_vm_grab_id(struct amdgpu_vm *vm, struct amdgpu_ring *ring,
> mutex_unlock(&id_mgr->lock);
> return r;
> }
> - fences = kmalloc_array(sizeof(void *), id_mgr->num_ids, GFP_KERNEL);
> - if (!fences) {
> - mutex_unlock(&id_mgr->lock);
> - return -ENOMEM;
> - }
> - /* Check if we have an idle VMID */
> - i = 0;
> - list_for_each_entry(idle, &id_mgr->ids_lru, list) {
> - fences[i] = amdgpu_sync_peek_fence(&idle->active, ring);
> - if (!fences[i])
> - break;
> - ++i;
> - }
> -
> - /* If we can't find a idle VMID to use, wait till one becomes available */
> - if (&idle->list == &id_mgr->ids_lru) {
> - u64 fence_context = adev->vm_manager.fence_context + ring->idx;
> - unsigned seqno = ++adev->vm_manager.seqno[ring->idx];
> - struct fence_array *array;
> - unsigned j;
> -
> - for (j = 0; j < i; ++j)
> - fence_get(fences[j]);
> -
> - array = fence_array_create(i, fences, fence_context,
> - seqno, true);
> - if (!array) {
> - for (j = 0; j < i; ++j)
> - fence_put(fences[j]);
> - kfree(fences);
> - r = -ENOMEM;
> - goto error;
> - }
> -
> -
> - r = amdgpu_sync_fence(ring->adev, sync, &array->base);
> - fence_put(&array->base);
> - if (r)
> - goto error;
> -
> - mutex_unlock(&id_mgr->lock);
> - return 0;
> -
> - }
> - kfree(fences);
>
> job->vm_needs_flush = false;
> /* Check if we can use a VMID already assigned to this VM */
> @@ -586,6 +541,53 @@ int amdgpu_vm_grab_id(struct amdgpu_vm *vm, struct amdgpu_ring *ring,
>
> };
>
> + fences = kmalloc_array(sizeof(void *), id_mgr->num_ids, GFP_KERNEL);
> + if (!fences) {
> + mutex_unlock(&id_mgr->lock);
> + return -ENOMEM;
> + }
> + /* Check if we have an idle VMID */
> + i = 0;
> + list_for_each_entry(idle, &id_mgr->ids_lru, list) {
> + fences[i] = amdgpu_sync_peek_fence(&idle->active, ring);
> + if (!fences[i])
> + break;
> + ++i;
> + }
> +
> + /* If we can't find a idle VMID to use, wait till one becomes available */
> + if (&idle->list == &id_mgr->ids_lru) {
> + u64 fence_context = adev->vm_manager.fence_context + ring->idx;
> + unsigned seqno = ++adev->vm_manager.seqno[ring->idx];
> + struct fence_array *array;
> + unsigned j;
> +
> + for (j = 0; j < i; ++j)
> + fence_get(fences[j]);
> +
> + array = fence_array_create(i, fences, fence_context,
> + seqno, true);
> + if (!array) {
> + for (j = 0; j < i; ++j)
> + fence_put(fences[j]);
> + kfree(fences);
> + r = -ENOMEM;
> + goto error;
> + }
> +
> +
> + r = amdgpu_sync_fence(ring->adev, sync, &array->base);
> + fence_put(&array->base);
> + if (r)
> + goto error;
> +
> + mutex_unlock(&id_mgr->lock);
> + return 0;
> +
> + }
> + kfree(fences);
> +
> +
> /* Still no ID to use? Then use the idle one found earlier */
> id = idle;
>
