perf header: Support HYBRID_CPU_PMU_CAPS feature
authorJin Yao <yao.jin@linux.intel.com>
Fri, 14 May 2021 12:29:48 +0000 (20:29 +0800)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Mon, 17 May 2021 13:58:10 +0000 (10:58 -0300)
commite119083bab80c2550065f6c0f10ba225a894595e
treeb25b45ca6bfd0002faa22852f94d132d2f32fe1b
parentf7d74ce32fc1b9b3cbf58c015009d1f616e60c23
perf header: Support HYBRID_CPU_PMU_CAPS feature

Perf has supported the CPU_PMU_CAPS feature to display a list of CPU PMU
capabilities. But on a hybrid platform, it may have several CPU PMUs (such
as "cpu_core" and "cpu_atom"). The CPU_PMU_CAPS feature is hard to extend
to support multiple CPU PMUs well if it needs to be compatible for the case
of old perf data file + new perf tool.

So for better compatibility we now create a new feature HYBRID_CPU_PMU_CAPS
in the header.

For the perf.data generated on hybrid platform,

  root@otcpl-adl-s-2:~# perf report --header-only -I

  # cpu_core pmu capabilities: branches=32, max_precise=3, pmu_name=alderlake_hybrid
  # cpu_atom pmu capabilities: branches=32, max_precise=3, pmu_name=alderlake_hybrid
  # missing features: TRACING_DATA BRANCH_STACK GROUP_DESC AUXTRACE STAT CLOCKID DIR_FORMAT COMPRESSED CPU_PMU_CAPS CLOCK_DATA

For the perf.data generated on non-hybrid platform

  root@kbl-ppc:~# perf report --header-only -I

  # cpu pmu capabilities: branches=32, max_precise=3, pmu_name=skylake
  # missing features: TRACING_DATA BRANCH_STACK GROUP_DESC AUXTRACE STAT CLOCKID DIR_FORMAT COMPRESSED CLOCK_DATA HYBRID_TOPOLOGY HYBRID_CPU_PMU_CAPS

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210514122948.9472-3-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/Documentation/perf.data-file-format.txt
tools/perf/util/env.c
tools/perf/util/env.h
tools/perf/util/header.c
tools/perf/util/header.h