Re: [PATCH 11/20] drm/amdgpu: fix KFD eviction fence enable_signaling path

["Kuehling, Felix" <felix.kuehling@amd.com>]

On 2025-11-13 09:37, Christian König wrote:
>>>> There is no need to enable-signaling (and trigger a preemption), if the eviction fence has already signaled.
>>> But when the evicted fence has already been signaled then enable_signaling is not called in the first place:
>>>
>>>           if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
>>>                   return false;
>>>
>>>           if (!was_set && fence->ops->enable_signaling) {
>>>                   trace_dma_fence_enable_signal(fence);
>>>
>>>                   if (!fence->ops->enable_signaling(fence)) {
>>> ...
>>>
>>> So the extra check is actually completely superfluous as far as I can see.
>> Thanks. I agree.
> Can I take that as reviewed-by you for this patch?

Yes.

Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>


>
> Thanks,
> Christian.
>
>> Regards,
>>    Felix
>>
>>
>>> Regards,
>>> Christian.
>>>
>>>> Regards,
>>>>     Felix
>>>>
>>>>
>>>>> Regards,
>>>>> Christian.
>>>>>
>>>>>> Regards,
>>>>>>      Felix
>>>>>>
>>>>>>
>>>>>>> Thanks,
>>>>>>> Christian.
>>>>>>>
>>>>>>>> P.
>>>>>>>>
>>>>>>>>> Signed-off-by: Christian König <christian.koenig@amd.com>
>>>>>>>>> ---
>>>>>>>>>      drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c | 6 ------
>>>>>>>>>      1 file changed, 6 deletions(-)
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
>>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
>>>>>>>>> index 1ef758ac5076..09c919f72b6c 100644
>>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
>>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
>>>>>>>>> @@ -120,12 +120,6 @@ static bool amdkfd_fence_enable_signaling(struct
>>>>>>>>> dma_fence *f)
>>>>>>>>>      {
>>>>>>>>>          struct amdgpu_amdkfd_fence *fence =
>>>>>>>>> to_amdgpu_amdkfd_fence(f);
>>>>>>>>>      -    if (!fence)
>>>>>>>>> -        return false;
>>>>>>>>> -
>>>>>>>>> -    if (dma_fence_is_signaled(f))
>>>>>>>>> -        return true;
>>>>>>>>> -
>>>>>>>>>          if (!fence->svm_bo) {
>>>>>>>>>              if
>>>>>>>>> (!kgd2kfd_schedule_evict_and_restore_process(fence->mm, f))
>>>>>>>>>                  return true;