Re: [PATCH v2 1/3] perf header: Support HYBRID_TOPOLOGY feature

[Jiri Olsa]

On Fri, May 07, 2021 at 11:52:28AM +0800, Jin Yao wrote:
> It would be useful to let user know the hybrid topology.
> Adding HYBRID_TOPOLOGY feature in header to indicate the
> core cpus and the atom cpus.
> 
> With this patch,
> 
> For the perf.data generated on hybrid platform,
> reports the hybrid cpu list.
> 
>   root@otcpl-adl-s-2:~# perf report --header-only -I
>   ...
>   # hybrid cpu system:
>   # cpu_core cpu list : 0-15
>   # cpu_atom cpu list : 16-23
> 
> For the perf.data generated on non-hybrid platform,
> reports the message that HYBRID_TOPOLOGY is missing.
> 
>   root@kbl-ppc:~# perf report --header-only -I
>   ...
>   # missing features: TRACING_DATA BRANCH_STACK GROUP_DESC AUXTRACE STAT CLOCKID DIR_FORMAT COMPRESSED CLOCK_DATA HYBRID_TOPOLOGY
> 
> Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> ---
>  .../Documentation/perf.data-file-format.txt   | 14 +++
>  tools/perf/util/cputopo.c                     | 80 +++++++++++++++++
>  tools/perf/util/cputopo.h                     | 13 +++
>  tools/perf/util/env.c                         |  6 ++
>  tools/perf/util/env.h                         |  7 ++
>  tools/perf/util/header.c                      | 87 +++++++++++++++++++
>  tools/perf/util/header.h                      |  1 +
>  tools/perf/util/pmu-hybrid.h                  | 11 +++
>  8 files changed, 219 insertions(+)
> 
> diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt
> index 9ee96640744e..d9d82ca8aeb7 100644
> --- a/tools/perf/Documentation/perf.data-file-format.txt
> +++ b/tools/perf/Documentation/perf.data-file-format.txt
> @@ -402,6 +402,20 @@ struct {
>  	u64 clockid_time_ns;
>  };
>  
> +	HEADER_HYBRID_TOPOLOGY = 30,
> +
> +Indicate the hybrid CPUs. The format of data is as below.
> +
> +struct {
> +	char *pmu_name;
> +	char *cpus;
> +};

this is missing the nr count, should be like:

struct {
	u32 nr;
	struct {
	     char *pmu_name;
	     char *cpus;
	} [nr]
}

jirka