On Tue, Jan 10, 2023 at 11:45:02PM +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>
> ---
> Changes in v2:
> - Include coccicheck make command in the patch log message for clarity.
> Suggested by Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Thank you
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
>
> drivers/gpu/drm/i915/display/intel_drrs.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_drrs.c b/drivers/gpu/drm/i915/display/intel_drrs.c
> index 5b9e44443814..84ba7379d6f8 100644
> --- a/drivers/gpu/drm/i915/display/intel_drrs.c
> +++ b/drivers/gpu/drm/i915/display/intel_drrs.c
> @@ -374,16 +374,16 @@ static int intel_drrs_debugfs_ctl_set(void *data, u64 val)
> return ret;
> }
>
> -DEFINE_SIMPLE_ATTRIBUTE(intel_drrs_debugfs_ctl_fops,
> - NULL, intel_drrs_debugfs_ctl_set, "%llu\n");
> +DEFINE_DEBUGFS_ATTRIBUTE(intel_drrs_debugfs_ctl_fops,
> + NULL, intel_drrs_debugfs_ctl_set, "%llu\n");
>
> void intel_drrs_crtc_debugfs_add(struct intel_crtc *crtc)
> {
> debugfs_create_file("i915_drrs_status", 0444, crtc->base.debugfs_entry,
> crtc, &intel_drrs_debugfs_status_fops);
>
> - debugfs_create_file("i915_drrs_ctl", 0644, crtc->base.debugfs_entry,
> - crtc, &intel_drrs_debugfs_ctl_fops);
> + debugfs_create_file_unsafe("i915_drrs_ctl", 0644, crtc->base.debugfs_entry,
> + crtc, &intel_drrs_debugfs_ctl_fops);
> }
>
> static int intel_drrs_debugfs_type_show(struct seq_file *m, void *unused)
> --
> 2.34.1
>
>
>
