The rcu_assign_pointer() ensures that the initialization of a structure is carried out before storing a pointer to that structre. It is always safe to use RCU_INIT_POINTER() to NULL a pointer, instead of rcu_assign_pointer(). This results in slightly smaller/faster code.
The following semantic patch was used: <smpl>
@@ @@
- rcu_assign_pointer + RCU_INIT_POINTER (..., NULL)
</smpl>
Signed-off-by: Muhammad Falak R Wani falakreyaz@gmail.com --- drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index d81f1f4..4500ff1 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -198,7 +198,7 @@ void amdgpu_fence_process(struct amdgpu_ring *ring)
/* There is always exactly one thread signaling this fence slot */ fence = rcu_dereference_protected(*ptr, 1); - rcu_assign_pointer(*ptr, NULL); + RCU_INIT_POINTER(*ptr, NULL);
BUG_ON(!fence);
Am 30.04.2016 um 21:00 schrieb Muhammad Falak R Wani:
The rcu_assign_pointer() ensures that the initialization of a structure is carried out before storing a pointer to that structre. It is always safe to use RCU_INIT_POINTER() to NULL a pointer, instead of rcu_assign_pointer(). This results in slightly smaller/faster code.
Thanks for the detailed explanation, I was already wondering what the difference is between the two.
The following semantic patch was used:
<smpl>
@@ @@
- rcu_assign_pointer
- RCU_INIT_POINTER (..., NULL)
</smpl>
Signed-off-by: Muhammad Falak R Wani falakreyaz@gmail.com
Reviewed-by: Christian König christian.koenig@amd.com
Regards, Christian.
drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index d81f1f4..4500ff1 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -198,7 +198,7 @@ void amdgpu_fence_process(struct amdgpu_ring *ring)
/* There is always exactly one thread signaling this fence slot */ fence = rcu_dereference_protected(*ptr, 1);
rcu_assign_pointer(*ptr, NULL);
RCU_INIT_POINTER(*ptr, NULL);BUG_ON(!fence);
On Sun, May 1, 2016 at 11:26 AM, Christian König christian.koenig@amd.com wrote:
Am 30.04.2016 um 21:00 schrieb Muhammad Falak R Wani:
The rcu_assign_pointer() ensures that the initialization of a structure is carried out before storing a pointer to that structre. It is always safe to use RCU_INIT_POINTER() to NULL a pointer, instead of rcu_assign_pointer(). This results in slightly smaller/faster code.
Thanks for the detailed explanation, I was already wondering what the difference is between the two.
The following semantic patch was used:
<smpl>
@@ @@
- rcu_assign_pointer
- RCU_INIT_POINTER (..., NULL)
</smpl>
Signed-off-by: Muhammad Falak R Wani falakreyaz@gmail.com
Reviewed-by: Christian König christian.koenig@amd.com
Applied. thanks!
Alex
Regards, Christian.
drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index d81f1f4..4500ff1 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -198,7 +198,7 @@ void amdgpu_fence_process(struct amdgpu_ring *ring) /* There is always exactly one thread signaling this fence slot */ fence = rcu_dereference_protected(*ptr, 1);
rcu_assign_pointer(*ptr, NULL);
RCU_INIT_POINTER(*ptr, NULL); BUG_ON(!fence);
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Alex Deucher -
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