On Tue, Jan 10, 2023 at 11:45:40PM +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>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
(Are you planning to send the one for pxp file?)
> ---
> Changes in v2:
> - Include coccicheck make command in the patch log message for clarity.
> Suggested by Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
>
>
> drivers/gpu/drm/i915/display/intel_fbc.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
> index 5e69d3c11d21..c508dcf415b4 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> @@ -1807,10 +1807,10 @@ static int intel_fbc_debugfs_false_color_set(void *data, u64 val)
> return 0;
> }
>
> -DEFINE_SIMPLE_ATTRIBUTE(intel_fbc_debugfs_false_color_fops,
> - intel_fbc_debugfs_false_color_get,
> - intel_fbc_debugfs_false_color_set,
> - "%llu\n");
> +DEFINE_DEBUGFS_ATTRIBUTE(intel_fbc_debugfs_false_color_fops,
> + intel_fbc_debugfs_false_color_get,
> + intel_fbc_debugfs_false_color_set,
> + "%llu\n");
>
> static void intel_fbc_debugfs_add(struct intel_fbc *fbc,
> struct dentry *parent)
> @@ -1819,8 +1819,8 @@ static void intel_fbc_debugfs_add(struct intel_fbc *fbc,
> fbc, &intel_fbc_debugfs_status_fops);
>
> if (fbc->funcs->set_false_color)
> - debugfs_create_file("i915_fbc_false_color", 0644, parent,
> - fbc, &intel_fbc_debugfs_false_color_fops);
> + debugfs_create_file_unsafe("i915_fbc_false_color", 0644, parent,
> + fbc, &intel_fbc_debugfs_false_color_fops);
> }
>
> void intel_fbc_crtc_debugfs_add(struct intel_crtc *crtc)
> --
> 2.34.1
>
>
>
