Messages in this thread Patch in this message | | | From | Jin Yao <> | Subject | [PATCH v2 1/4] perf pmu: Skip invalid hybrid pmu | Date | Thu, 8 Jul 2021 09:36:58 +0800 |
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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> --- tools/perf/util/pmu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 88c8ecdc60b0..cb20a9f69a04 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -927,6 +927,13 @@ 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 @@ -955,7 +962,7 @@ 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); -- 2.17.1
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