From 77c34ef1c3194bfac65883af75baf7dec9fa0d77 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 13 Jul 2016 17:16:18 +0000 Subject: [PATCH] perf/x86/intel/cstate: Convert Intel CSTATE to hotplug state machine Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Anna-Maria Gleixner Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Dave Hansen Cc: Jiri Olsa Cc: Kan Liang Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: kbuild test robot Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153334.184061086@linutronix.de Signed-off-by: Ingo Molnar --- arch/x86/events/intel/cstate.c | 53 ++++++++++------------------------ include/linux/cpuhotplug.h | 2 ++ 2 files changed, 18 insertions(+), 37 deletions(-) diff --git a/arch/x86/events/intel/cstate.c b/arch/x86/events/intel/cstate.c index 9ba4e4136a15..d6d7be0b3495 100644 --- a/arch/x86/events/intel/cstate.c +++ b/arch/x86/events/intel/cstate.c @@ -365,7 +365,7 @@ static int cstate_pmu_event_add(struct perf_event *event, int mode) * Check if exiting cpu is the designated reader. If so migrate the * events when there is a valid target available */ -static void cstate_cpu_exit(int cpu) +static int cstate_cpu_exit(unsigned int cpu) { unsigned int target; @@ -390,9 +390,10 @@ static void cstate_cpu_exit(int cpu) perf_pmu_migrate_context(&cstate_pkg_pmu, cpu, target); } } + return 0; } -static void cstate_cpu_init(int cpu) +static int cstate_cpu_init(unsigned int cpu) { unsigned int target; @@ -414,31 +415,10 @@ static void cstate_cpu_init(int cpu) topology_core_cpumask(cpu)); if (has_cstate_pkg && target >= nr_cpu_ids) cpumask_set_cpu(cpu, &cstate_pkg_cpu_mask); + + return 0; } -static int cstate_cpu_notifier(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - unsigned int cpu = (long)hcpu; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_STARTING: - cstate_cpu_init(cpu); - break; - case CPU_DOWN_PREPARE: - cstate_cpu_exit(cpu); - break; - default: - break; - } - return NOTIFY_OK; -} - -static struct notifier_block cstate_cpu_nb = { - .notifier_call = cstate_cpu_notifier, - .priority = CPU_PRI_PERF + 1, -}; - static struct pmu cstate_core_pmu = { .attr_groups = core_attr_groups, .name = "cstate_core", @@ -599,18 +579,20 @@ static inline void cstate_cleanup(void) static int __init cstate_init(void) { - int cpu, err; + int err; - cpu_notifier_register_begin(); - for_each_online_cpu(cpu) - cstate_cpu_init(cpu); + cpuhp_setup_state(CPUHP_AP_PERF_X86_CSTATE_STARTING, + "AP_PERF_X86_CSTATE_STARTING", cstate_cpu_init, + NULL); + cpuhp_setup_state(CPUHP_AP_PERF_X86_CSTATE_ONLINE, + "AP_PERF_X86_CSTATE_ONLINE", NULL, cstate_cpu_exit); if (has_cstate_core) { err = perf_pmu_register(&cstate_core_pmu, cstate_core_pmu.name, -1); if (err) { has_cstate_core = false; pr_info("Failed to register cstate core pmu\n"); - goto out; + return err; } } @@ -620,12 +602,10 @@ static int __init cstate_init(void) has_cstate_pkg = false; pr_info("Failed to register cstate pkg pmu\n"); cstate_cleanup(); - goto out; + return err; } } - __register_cpu_notifier(&cstate_cpu_nb); -out: - cpu_notifier_register_done(); + return err; } @@ -651,9 +631,8 @@ module_init(cstate_pmu_init); static void __exit cstate_pmu_exit(void) { - cpu_notifier_register_begin(); - __unregister_cpu_notifier(&cstate_cpu_nb); + cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_ONLINE); + cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_STARTING); cstate_cleanup(); - cpu_notifier_register_done(); } module_exit(cstate_pmu_exit); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index f9399eeba263..68f4495f4988 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -26,6 +26,7 @@ enum cpuhp_state { CPUHP_AP_PERF_X86_STARTING, CPUHP_AP_PERF_X86_AMD_IBS_STARTING, CPUHP_AP_PERF_X86_CQM_STARTING, + CPUHP_AP_PERF_X86_CSTATE_STARTING, CPUHP_AP_NOTIFY_STARTING, CPUHP_AP_ONLINE, CPUHP_TEARDOWN_CPU, @@ -38,6 +39,7 @@ enum cpuhp_state { CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE, CPUHP_AP_PERF_X86_RAPL_ONLINE, CPUHP_AP_PERF_X86_CQM_ONLINE, + CPUHP_AP_PERF_X86_CSTATE_ONLINE, CPUHP_AP_NOTIFY_ONLINE, CPUHP_AP_ONLINE_DYN, CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,