Re: [PATCH v2 3/5] driver/perf: Add identifier sysfs file for Yitian 710 DDR

[John Garry <john.g.garry@oracle.com>]

On 24/04/2023 10:44, Jing Zhang wrote:
> To allow userspace to identify the specific implementation of the device,
> add an "identifier" sysfs file.
> 
> The perf tool can match the Yitian 710 DDR metric through the identifier.
> 
> Signed-off-by: Jing Zhang<renyu.zj@linux.alibaba.com>
> ---
>   drivers/perf/alibaba_uncore_drw_pmu.c | 27 +++++++++++++++++++++++++++
>   1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/perf/alibaba_uncore_drw_pmu.c b/drivers/perf/alibaba_uncore_drw_pmu.c
> index a7689fe..fe075fd 100644
> --- a/drivers/perf/alibaba_uncore_drw_pmu.c
> +++ b/drivers/perf/alibaba_uncore_drw_pmu.c
> @@ -236,10 +236,37 @@ static ssize_t ali_drw_pmu_cpumask_show(struct device *dev,
>   	.attrs = ali_drw_pmu_cpumask_attrs,
>   };
>   
> +static ssize_t ali_drw_pmu_identifier_show(struct device *dev,
> +					struct device_attribute *attr,
> +					char *page)
> +{
> +	return sysfs_emit(page, "%s\n", "ali_drw_pmu");
> +}

Would there be anything more unique per implementation version? Having a 
constant like this means that all implementations will have same events 
from userspace PoV.

Thanks,
John