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perf pmu: Skip invalid hybrid pmu

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On hybrid platform, such as Alderlake, if atom CPUs are offlined,
the kernel still exports the sysfs path '/sys/devices/cpu_atom/' for
'cpu_atom' pmu but the file '/sys/devices/cpu_atom/cpus' is empty,
which indicates this is an invalid pmu.

Need to check and skip the invalid hybrid pmu.

Before:

  # perf list
  ...
  branch-instructions OR cpu_atom/branch-instructions/ [Kernel PMU event]
  branch-instructions OR cpu_core/branch-instructions/ [Kernel PMU event]
  branch-misses OR cpu_atom/branch-misses/           [Kernel PMU event]
  branch-misses OR cpu_core/branch-misses/           [Kernel PMU event]
  bus-cycles OR cpu_atom/bus-cycles/                 [Kernel PMU event]
  bus-cycles OR cpu_core/bus-cycles/                 [Kernel PMU event]
  ...

The cpu_atom events are still displayed even if atom CPUs are offlined.

After:

  # perf list
  ...
  branch-instructions OR cpu_core/branch-instructions/ [Kernel PMU event]
  branch-misses OR cpu_core/branch-misses/           [Kernel PMU event]
  bus-cycles OR cpu_core/bus-cycles/                 [Kernel PMU event]
  ...

Now only cpu_core events are displayed.

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/20210708013701.20347-2-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jin Yao 2021-07-08 09:36:58 +08:00 committed by Arnaldo Carvalho de Melo
parent 40226a3d96
commit 49afa7f6c7
1 changed files with 8 additions and 1 deletions
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9
tools/perf/util/pmu.c
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@ -950,6 +950,13 @@ static struct perf_pmu *pmu_lookup(const char *name)
LIST_HEAD(format);
LIST_HEAD(aliases);
__u32 type;
bool is_hybrid = perf_pmu__hybrid_mounted(name);
/*
* Check pmu name for hybrid and the pmu may be invalid in sysfs
*/
if (!strncmp(name, "cpu_", 4) && !is_hybrid)
return NULL;
/*
* The pmu data we store & need consists of the pmu
@ -978,7 +985,7 @@ static struct perf_pmu *pmu_lookup(const char *name)
pmu->is_uncore = pmu_is_uncore(name);
if (pmu->is_uncore)
pmu->id = pmu_id(name);
pmu->is_hybrid = perf_pmu__hybrid_mounted(name);
pmu->is_hybrid = is_hybrid;
pmu->max_precise = pmu_max_precise(name);
pmu_add_cpu_aliases(&aliases, pmu);
pmu_add_sys_aliases(&aliases, pmu);