[PATCH 02/17] drm/xe/perf/uapi: Add perf_stream_paranoid sysctl

[Dixit, Ashutosh]

On Thu, 07 Dec 2023 22:43:14 -0800, Ashutosh Dixit wrote:
>
> +static struct ctl_table perf_ctl_table[] = {
> +	{
> +	 .procname = "perf_stream_paranoid",
> +	 .data = &xe_perf_stream_paranoid,
> +	 .maxlen = sizeof(xe_perf_stream_paranoid),
> +	 .mode = 0644,
> +	 .proc_handler = proc_dointvec_minmax,
> +	 .extra1 = SYSCTL_ZERO,
> +	 .extra2 = SYSCTL_ONE,
> +	 },
> +	{}
> +};
> +
> +int xe_perf_sysctl_register(void)
> +{
> +	sysctl_header = register_sysctl("dev/xe", perf_ctl_table);
> +	return 0;
> +}

Any idea why this (and xe_oa_max_sample_rate) is create in /proc, rather
than something attached to the module?

We would want it to be per module, rather than per device, so that's one
reason. What are the options for creating per module params? One is
module_param itself. In that case this would appear in
"/sys/module/xe/parameters/perf_stream_paranoid" rather than in
"/proc/sys/dev/xe/perf_stream_paranoid".

Module params are slightly simpler to manage than /proc stuff I think. Any
other reason to prefer one over the other?

Comments?

Thanks.
--
Ashutosh