Am 14.03.25 um 05:09 schrieb SRINIVASAN SHANMUGAM:
>
> On 3/7/2025 7:18 PM, Christian König wrote:
>> We keep the gang submission fence around in adev, make sure that it
>> stays alive.
>>
>> v2: fix memory leak on retry
>>
>> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 10 +++++++++-
>> 1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index 198d29faa754..337543ec615c 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -6889,18 +6889,26 @@ struct dma_fence *amdgpu_device_switch_gang(struct amdgpu_device *adev,
>> {
>> struct dma_fence *old = NULL;
>> + dma_fence_get(gang);
>> do {
>> dma_fence_put(old);
>> old = amdgpu_device_get_gang(adev);
>> if (old == gang)
>> break;
>> - if (!dma_fence_is_signaled(old))
>> + if (!dma_fence_is_signaled(old)) {
>
> Here, should we need to check ?
The gang is initialized to a dummy fence on bootup. So even when there is never any gang submission the old value is never NULL.
Regards,
Christian.
>
> // Check if old fence isn't signaled
> if (old && !dma_fence_is_signaled(old)) {
>
>> + dma_fence_put(gang);
>> return old;
>> + }
>> } while (cmpxchg((struct dma_fence __force **)&adev->gang_submit,
>> old, gang) != old);
>> + /*
>> + * Drop it once for the exchanged reference in adev and once for the
>> + * thread local reference acquired in amdgpu_device_get_gang().
>> + */
>> + dma_fence_put(old);
>
> if (old)
> dma_fence_put(old); // Ensure to release old reference only if it is valid?
>
>
>> dma_fence_put(old);
>> return NULL;
>> }
