From 49afa7f6c714ab3f5cb2a4c835f7f9dddc0bb2c1 Mon Sep 17 00:00:00 2001 From: Jin Yao <yao.jin@linux.intel.com> Date: Thu, 8 Jul 2021 09:36:58 +0800 Subject: [PATCH] perf pmu: Skip invalid hybrid pmu 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> --- 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 44b90d638ad5f..a1bd7007a8b4d 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -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); -- 2.39.5