On 2025-11-06 11:46, Christian König wrote:
On 11/6/25 17:37, Kuehling, Felix wrote:
On 2025-11-06 08:43, Christian König wrote:
On 11/4/25 17:28, Philipp Stanner wrote:
On Fri, 2025-10-31 at 14:16 +0100, Christian König wrote:
Calling dma_fence_is_signaled() here is illegal!
The series was sent as a v2. But is this still an RFC?
I think when Matthew came up with the XE patches we pretty much agreed that
this is the way to go.
If not, more detailed commit messages are a desirable thing.
Good point, how about:
The enable_signaling callback is called with the same irqsave spinlock held
than dma_fence_is_signaled() tries to grab. That will 100% reliable deadlock if
that happens.
I guess we could use dma_fence_is_signaled_locked instead. That said, it only tries
to take the lock (in dma_fence_signal) if fence->ops->signal is set, which
isn't the case for these fences. That's why this has never caused a problem up till
now.
But when fence->ops->signal isn't set then why are we calling this?
There is no need to enable-signaling (and trigger a preemption), if the
eviction fence has already signaled.
Regards,
Felix
Regards,
Christian.
Regards,
Felix
Thanks,
Christian.
P.
Signed-off-by: Christian König <[email protected]>
---
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;
