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

[Jin, Yao]

Hi Jiri,

On 5/10/2021 9:11 PM, Jiri Olsa wrote:
> 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

Yes, we should say the format of data is:

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

I will update 'perf.data-file-format.txt' in v3.

Thanks
Jin Yao