Re: [PATCH 1/3] drm/radeon: fix VMID use tracking

["Christian König" <deathsimple@vodafone.de>]

Am 23.01.2014 18:46, schrieb Alex Deucher:
> On Thu, Jan 23, 2014 at 8:24 AM, Christian König
> <deathsimple@vodafone.de> wrote:
>> From: Christian König <christian.koenig@amd.com>
>>
>> Otherwise we allocate a new VMID on nearly every submit.
> I wonder if this fix would allow us to fix up this:
> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=466476dfdcafbb4286ffa232a3a792731b9dc852

It's probably a step into the right direction, but not necessary the 
complete solution.

For now I would say we should keep the extra flushing as it is.

Christian.

> Alex
>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> ---
>>   drivers/gpu/drm/radeon/radeon.h      | 2 ++
>>   drivers/gpu/drm/radeon/radeon_gart.c | 8 +++++++-
>>   2 files changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
>> index c5519ca..4a8ac1c 100644
>> --- a/drivers/gpu/drm/radeon/radeon.h
>> +++ b/drivers/gpu/drm/radeon/radeon.h
>> @@ -867,6 +867,8 @@ struct radeon_vm {
>>          struct radeon_fence             *fence;
>>          /* last flush or NULL if we still need to flush */
>>          struct radeon_fence             *last_flush;
>> +       /* last use of vmid */
>> +       struct radeon_fence             *last_id_use;
>>   };
>>
>>   struct radeon_vm_manager {
>> diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
>> index 96e4400..0e9143b 100644
>> --- a/drivers/gpu/drm/radeon/radeon_gart.c
>> +++ b/drivers/gpu/drm/radeon/radeon_gart.c
>> @@ -713,7 +713,7 @@ struct radeon_fence *radeon_vm_grab_id(struct radeon_device *rdev,
>>          unsigned i;
>>
>>          /* check if the id is still valid */
>> -       if (vm->fence && vm->fence == rdev->vm_manager.active[vm->id])
>> +       if (vm->last_id_use && vm->last_id_use == rdev->vm_manager.active[vm->id])
>>                  return NULL;
>>
>>          /* we definately need to flush */
>> @@ -769,6 +769,9 @@ void radeon_vm_fence(struct radeon_device *rdev,
>>
>>          radeon_fence_unref(&vm->fence);
>>          vm->fence = radeon_fence_ref(fence);
>> +
>> +       radeon_fence_unref(&vm->last_id_use);
>> +       vm->last_id_use = radeon_fence_ref(fence);
>>   }
>>
>>   /**
>> @@ -1303,6 +1306,8 @@ void radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
>>   {
>>          vm->id = 0;
>>          vm->fence = NULL;
>> +       vm->last_flush = NULL;
>> +       vm->last_id_use = NULL;
>>          mutex_init(&vm->mutex);
>>          INIT_LIST_HEAD(&vm->list);
>>          INIT_LIST_HEAD(&vm->va);
>> @@ -1341,5 +1346,6 @@ void radeon_vm_fini(struct radeon_device *rdev, struct radeon_vm *vm)
>>          }
>>          radeon_fence_unref(&vm->fence);
>>          radeon_fence_unref(&vm->last_flush);
>> +       radeon_fence_unref(&vm->last_id_use);
>>          mutex_unlock(&vm->mutex);
>>   }
>> --
>> 1.8.1.2
>>