Re: [PATCH v2 2/8] i915: simplify subdirectory registration with register_sysctl()

From: Jani Nikula <jani.nikula@linux.intel.com>
To: Luis Chamberlain <mcgrof@kernel.org>,
	akpm@linux-foundation.org, keescook@chromium.org,
	yzaikin@google.com, nixiaoming@huawei.com, ebiederm@xmission.com,
	clemens@ladisch.de, arnd@arndb.de, gregkh@linuxfoundation.org,
	joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com,
	tvrtko.ursulin@linux.intel.com, airlied@linux.ie,
	daniel@ffwll.chairlied, benh@kernel.crashing.org,
	mark@fasheh.com, jlbec@evilplan.org, joseph.qi@linux.alibaba.com,
	jack@suse.cz, amir73il@gmail.com, phil@philpotter.co.uk,
	viro@zeniv.linux.org.uk, julia.lawall@inria.fr
Cc: ocfs2-devel@oss.oracle.com, linuxppc-dev@lists.ozlabs.org,
	intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Luis Chamberlain <mcgrof@kernel.org>
Subject: Re: [PATCH v2 2/8] i915: simplify subdirectory registration with register_sysctl()
Date: Thu, 25 Nov 2021 11:41:30 +0200	[thread overview]
Message-ID: <87fsrklghh.fsf@intel.com> (raw)
In-Reply-To: <20211123202422.819032-3-mcgrof@kernel.org>

On Tue, 23 Nov 2021, Luis Chamberlain <mcgrof@kernel.org> wrote:
> There is no need to user boiler plate code to specify a set of base
> directories we're going to stuff sysctls under. Simplify this by using
> register_sysctl() and specifying the directory path directly.

\o/

Acked-by: Jani Nikula <jani.nikula@intel.com>

>
> // pycocci sysctl-subdir-register-sysctl-simplify.cocci PATH
>
> @c1@
> expression E1;
> identifier subdir, sysctls;
> @@
>
> static struct ctl_table subdir[] = {
> 	{
> 		.procname = E1,
> 		.maxlen = 0,
> 		.mode = 0555,
> 		.child = sysctls,
> 	},
> 	{ }
> };
>
> @c2@
> identifier c1.subdir;
>
> expression E2;
> identifier base;
> @@
>
> static struct ctl_table base[] = {
> 	{
> 		.procname = E2,
> 		.maxlen = 0,
> 		.mode = 0555,
> 		.child = subdir,
> 	},
> 	{ }
> };
>
> @c3@
> identifier c2.base;
> identifier header;
> @@
>
> header = register_sysctl_table(base);
>
> @r1 depends on c1 && c2 && c3@
> expression c1.E1;
> identifier c1.subdir, c1.sysctls;
> @@
>
> -static struct ctl_table subdir[] = {
> -	{
> -		.procname = E1,
> -		.maxlen = 0,
> -		.mode = 0555,
> -		.child = sysctls,
> -	},
> -	{ }
> -};
>
> @r2 depends on c1 && c2 && c3@
> identifier c1.subdir;
>
> expression c2.E2;
> identifier c2.base;
> @@
> -static struct ctl_table base[] = {
> -	{
> -		.procname = E2,
> -		.maxlen = 0,
> -		.mode = 0555,
> -		.child = subdir,
> -	},
> -	{ }
> -};
>
> @initialize:python@
> @@
>
> def make_my_fresh_expression(s1, s2):
>   return '"' + s1.strip('"') + "/" + s2.strip('"') + '"'
>
> @r3 depends on c1 && c2 && c3@
> expression c1.E1;
> identifier c1.sysctls;
> expression c2.E2;
> identifier c2.base;
> identifier c3.header;
> fresh identifier E3 = script:python(E2, E1) { make_my_fresh_expression(E2, E1) };
> @@
>
> header =
> -register_sysctl_table(base);
> +register_sysctl(E3, sysctls);
>
> Generated-by: Coccinelle SmPL
> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
> ---
>  drivers/gpu/drm/i915/i915_perf.c | 22 +---------------------
>  1 file changed, 1 insertion(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index 2f01b8c0284c..5979e3258647 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -4273,26 +4273,6 @@ static struct ctl_table oa_table[] = {
>  	{}
>  };
>  
> -static struct ctl_table i915_root[] = {
> -	{
> -	 .procname = "i915",
> -	 .maxlen = 0,
> -	 .mode = 0555,
> -	 .child = oa_table,
> -	 },
> -	{}
> -};
> -
> -static struct ctl_table dev_root[] = {
> -	{
> -	 .procname = "dev",
> -	 .maxlen = 0,
> -	 .mode = 0555,
> -	 .child = i915_root,
> -	 },
> -	{}
> -};
> -
>  static void oa_init_supported_formats(struct i915_perf *perf)
>  {
>  	struct drm_i915_private *i915 = perf->i915;
> @@ -4488,7 +4468,7 @@ static int destroy_config(int id, void *p, void *data)
>  
>  int i915_perf_sysctl_register(void)
>  {
> -	sysctl_header = register_sysctl_table(dev_root);
> +	sysctl_header = register_sysctl("dev/i915", oa_table);
>  	return 0;
>  }

-- 
Jani Nikula, Intel Open Source Graphics Center