On Wed, Jan 11, 2023 at 12:00:12AM +0530, Deepak R Varma wrote:
> Using DEFINE_SIMPLE_ATTRIBUTE macro with the debugfs_create_file()
> function adds the overhead of introducing a proxy file operation
> functions to wrap the original read/write inside file removal protection
> functions. This adds significant overhead in terms of introducing and
> managing the proxy factory file operations structure and function
> wrapping at runtime.
> As a replacement, a combination of DEFINE_DEBUGFS_ATTRIBUTE macro paired
> with debugfs_create_file_unsafe() is suggested to be used instead. The
> DEFINE_DEBUGFS_ATTRIBUTE utilises debugfs_file_get() and
> debugfs_file_put() wrappers to protect the original read and write
> function calls for the debug attributes. There is no need for any
> runtime proxy file operations to be managed by the debugfs core.
> Following coccicheck make command helped identify this change:
>
> make coccicheck M=drivers/gpu/drm/i915/ MODE=patch COCCI=./scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci
>
> Signed-off-by: Deepak R Varma <drv@xxxxxxxxx>
I believe these 2 gvt cases could be done in one patch.
But anyways,
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
for both patches... and will leave these 2 patches for gvt folks
to apply. Unless they ack and I apply in the drm-intel along with the other ones.
> ---
> drivers/gpu/drm/i915/gvt/debugfs.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/debugfs.c b/drivers/gpu/drm/i915/gvt/debugfs.c
> index 03f081c3d9a4..baccbf1761b7 100644
> --- a/drivers/gpu/drm/i915/gvt/debugfs.c
> +++ b/drivers/gpu/drm/i915/gvt/debugfs.c
> @@ -165,7 +165,7 @@ static int vgpu_status_get(void *data, u64 *val)
> return 0;
> }
>
> -DEFINE_SIMPLE_ATTRIBUTE(vgpu_status_fops, vgpu_status_get, NULL, "0x%llx\n");
> +DEFINE_DEBUGFS_ATTRIBUTE(vgpu_status_fops, vgpu_status_get, NULL, "0x%llx\n");
>
> /**
> * intel_gvt_debugfs_add_vgpu - register debugfs entries for a vGPU
> @@ -182,8 +182,8 @@ void intel_gvt_debugfs_add_vgpu(struct intel_vgpu *vgpu)
> &vgpu_mmio_diff_fops);
> debugfs_create_file_unsafe("scan_nonprivbb", 0644, vgpu->debugfs, vgpu,
> &vgpu_scan_nonprivbb_fops);
> - debugfs_create_file("status", 0644, vgpu->debugfs, vgpu,
> - &vgpu_status_fops);
> + debugfs_create_file_unsafe("status", 0644, vgpu->debugfs, vgpu,
> + &vgpu_status_fops);
> }
>
> /**
> --
> 2.34.1
>
>
>
