From: Richard Cochran Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Signed-off-by: Richard Cochran Reviewed-by: Sebastian Andrzej Siewior Signed-off-by: Anna-Maria Gleixner --- arch/x86/events/intel/rapl.c | 84 ++++++++++++------------------------------- include/linux/cpuhotplug.h | 2 + 2 files changed, 27 insertions(+), 59 deletions(-) --- a/arch/x86/events/intel/rapl.c +++ b/arch/x86/events/intel/rapl.c @@ -555,14 +555,14 @@ const struct attribute_group *rapl_attr_ NULL, }; -static void rapl_cpu_exit(int cpu) +static int rapl_cpu_offline(unsigned int cpu) { struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu); int target; /* Check if exiting cpu is used for collecting rapl events */ if (!cpumask_test_and_clear_cpu(cpu, &rapl_cpu_mask)) - return; + return 0; pmu->cpu = -1; /* Find a new cpu to collect rapl events */ @@ -574,9 +574,10 @@ static void rapl_cpu_exit(int cpu) pmu->cpu = target; perf_pmu_migrate_context(pmu->pmu, cpu, target); } + return 0; } -static void rapl_cpu_init(int cpu) +static int rapl_cpu_online(unsigned int cpu) { struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu); int target; @@ -587,13 +588,14 @@ static void rapl_cpu_init(int cpu) */ target = cpumask_any_and(&rapl_cpu_mask, topology_core_cpumask(cpu)); if (target < nr_cpu_ids) - return; + return 0; cpumask_set_cpu(cpu, &rapl_cpu_mask); pmu->cpu = cpu; + return 0; } -static int rapl_cpu_prepare(int cpu) +static int rapl_cpu_prepare(unsigned int cpu) { struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu); @@ -614,33 +616,6 @@ static int rapl_cpu_prepare(int cpu) return 0; } -static int rapl_cpu_notifier(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - unsigned int cpu = (long)hcpu; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_UP_PREPARE: - rapl_cpu_prepare(cpu); - break; - - case CPU_DOWN_FAILED: - case CPU_ONLINE: - rapl_cpu_init(cpu); - break; - - case CPU_DOWN_PREPARE: - rapl_cpu_exit(cpu); - break; - } - return NOTIFY_OK; -} - -static struct notifier_block rapl_cpu_nb = { - .notifier_call = rapl_cpu_notifier, - .priority = CPU_PRI_PERF + 1, -}; - static int rapl_check_hw_unit(bool apply_quirk) { u64 msr_rapl_power_unit_bits; @@ -691,24 +666,6 @@ static void __init rapl_advertise(void) } } -static int __init rapl_prepare_cpus(void) -{ - unsigned int cpu, pkg; - int ret; - - for_each_online_cpu(cpu) { - pkg = topology_logical_package_id(cpu); - if (rapl_pmus->pmus[pkg]) - continue; - - ret = rapl_cpu_prepare(cpu); - if (ret) - return ret; - rapl_cpu_init(cpu); - } - return 0; -} - static void cleanup_rapl_pmus(void) { int i; @@ -835,35 +792,44 @@ static int __init rapl_pmu_init(void) if (ret) return ret; - cpu_notifier_register_begin(); + /* + * Install callbacks. Core will call them for each online cpu. + */ - ret = rapl_prepare_cpus(); + ret = cpuhp_setup_state(CPUHP_PERF_X86_RAPL_PREP, "PERF_X86_RAPL_PREP", + rapl_cpu_prepare, NULL); if (ret) goto out; + ret = cpuhp_setup_state(CPUHP_AP_PERF_X86_RAPL_ONLINE, + "AP_PERF_X86_RAPL_ONLINE", + rapl_cpu_online, rapl_cpu_offline); + if (ret) + goto out1; + ret = perf_pmu_register(&rapl_pmus->pmu, "power", -1); if (ret) - goto out; + goto out2; - __register_cpu_notifier(&rapl_cpu_nb); - cpu_notifier_register_done(); rapl_advertise(); return 0; +out2: + cpuhp_remove_state(CPUHP_AP_PERF_X86_RAPL_ONLINE); +out1: + cpuhp_remove_state(CPUHP_PERF_X86_RAPL_PREP); out: pr_warn("Initialization failed (%d), disabled\n", ret); cleanup_rapl_pmus(); - cpu_notifier_register_done(); return ret; } module_init(rapl_pmu_init); static void __exit intel_rapl_exit(void) { - cpu_notifier_register_begin(); - __unregister_cpu_notifier(&rapl_cpu_nb); + cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_RAPL_ONLINE); + cpuhp_remove_state_nocalls(CPUHP_PERF_X86_RAPL_PREP); perf_pmu_unregister(&rapl_pmus->pmu); cleanup_rapl_pmus(); - cpu_notifier_register_done(); } module_exit(intel_rapl_exit); --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -8,6 +8,7 @@ enum cpuhp_state { CPUHP_PERF_X86_PREPARE, CPUHP_PERF_X86_UNCORE_PREP, CPUHP_PERF_X86_AMD_UNCORE_PREP, + CPUHP_PERF_X86_RAPL_PREP, CPUHP_NOTIFY_PREPARE, CPUHP_BRINGUP_CPU, CPUHP_AP_IDLE_DEAD, @@ -34,6 +35,7 @@ enum cpuhp_state { CPUHP_AP_PERF_X86_ONLINE, CPUHP_AP_PERF_X86_UNCORE_ONLINE, CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE, + CPUHP_AP_PERF_X86_RAPL_ONLINE, CPUHP_AP_NOTIFY_ONLINE, CPUHP_AP_ONLINE_DYN, CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,