2019-09-05 05:54:35

by zhong jiang

Subject: [PATCH v2] drm/amdgpu: Remove two redundant null pointer checks

The functions "debugfs_remove" and "kfree" tolerate the passing
of null pointers. Hence it is unnecessary to check such arguments
around the calls. Thus remove the extra condition check at two places.

Signed-off-by: zhong jiang <[email protected]>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 5652cc7..cb94627 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1077,8 +1077,7 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val)

ttm_bo_unlock_delayed_workqueue(&adev->mman.bdev, resched);

- if (fences)
- kfree(fences);
+ kfree(fences);

return 0;
}
@@ -1103,8 +1102,7 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev)

void amdgpu_debugfs_preempt_cleanup(struct amdgpu_device *adev)
{
- if (adev->debugfs_preempt)
- debugfs_remove(adev->debugfs_preempt);
+ debugfs_remove(adev->debugfs_preempt);
}

#else
--
1.7.12.4

2019-09-05 05:57:03

by Zhou, David(ChunMing)

Subject: Re: [PATCH v2] drm/amdgpu: Remove two redundant null pointer checks

On 2019/9/5 下午1:49, zhong jiang wrote:
> The functions "debugfs_remove" and "kfree" tolerate the passing
> of null pointers. Hence it is unnecessary to check such arguments
> around the calls. Thus remove the extra condition check at two places.
>
> Signed-off-by: zhong jiang <[email protected]>

Reviewed-by: Chunming Zhou <[email protected]>


> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> index 5652cc7..cb94627 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> @@ -1077,8 +1077,7 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val)
>
> ttm_bo_unlock_delayed_workqueue(&adev->mman.bdev, resched);
>
> - if (fences)
> - kfree(fences);
> + kfree(fences);
>
> return 0;
> }
> @@ -1103,8 +1102,7 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev)
>
> void amdgpu_debugfs_preempt_cleanup(struct amdgpu_device *adev)
> {
> - if (adev->debugfs_preempt)
> - debugfs_remove(adev->debugfs_preempt);
> + debugfs_remove(adev->debugfs_preempt);
> }
>
> #else

2019-09-05 08:57:45

by Markus Elfring

Subject: Re: [v2] drm/amdgpu: Remove two redundant null pointer checks

> The functions "debugfs_remove" and "kfree" tolerate the passing
> of null pointers. Hence it is unnecessary to check such arguments
> around the calls. Thus remove the extra condition check at two places.

Will a tag like “Generated-by: scripts/coccinelle/free/ifnullfree.cocci” be relevant here?

How do you think about to compare this change approach with another patch variant?

drm/amdgpu: Delete an unnecessary check before two function calls
https://lkml.org/lkml/2019/9/4/401
https://lore.kernel.org/patchwork/patch/1123689/
https://lore.kernel.org/r/[email protected]/

Regards,
Markus