diff options
51 files changed, 550 insertions, 226 deletions
diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt index be675d2d15a7..a0b005d2bd95 100644 --- a/Documentation/cpu-hotplug.txt +++ b/Documentation/cpu-hotplug.txt @@ -312,12 +312,57 @@ things will happen if a notifier in path sent a BAD notify code. Q: I don't see my action being called for all CPUs already up and running? A: Yes, CPU notifiers are called only when new CPUs are on-lined or offlined. If you need to perform some action for each cpu already in the system, then + do this: for_each_online_cpu(i) { foobar_cpu_callback(&foobar_cpu_notifier, CPU_UP_PREPARE, i); foobar_cpu_callback(&foobar_cpu_notifier, CPU_ONLINE, i); } + However, if you want to register a hotplug callback, as well as perform + some initialization for CPUs that are already online, then do this: + + Version 1: (Correct) + --------- + + cpu_notifier_register_begin(); + + for_each_online_cpu(i) { + foobar_cpu_callback(&foobar_cpu_notifier, + CPU_UP_PREPARE, i); + foobar_cpu_callback(&foobar_cpu_notifier, + CPU_ONLINE, i); + } + + /* Note the use of the double underscored version of the API */ + __register_cpu_notifier(&foobar_cpu_notifier); + + cpu_notifier_register_done(); + + Note that the following code is *NOT* the right way to achieve this, + because it is prone to an ABBA deadlock between the cpu_add_remove_lock + and the cpu_hotplug.lock. + + Version 2: (Wrong!) + --------- + + get_online_cpus(); + + for_each_online_cpu(i) { + foobar_cpu_callback(&foobar_cpu_notifier, + CPU_UP_PREPARE, i); + foobar_cpu_callback(&foobar_cpu_notifier, + CPU_ONLINE, i); + } + + register_cpu_notifier(&foobar_cpu_notifier); + + put_online_cpus(); + + So always use the first version shown above when you want to register + callbacks as well as initialize the already online CPUs. + + Q: If i would like to develop cpu hotplug support for a new architecture, what do i need at a minimum? A: The following are what is required for CPU hotplug infrastructure to work diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index 9da35c6d3411..4d963fb66e3f 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -1073,6 +1073,8 @@ static int __init arch_hw_breakpoint_init(void) core_num_brps = get_num_brps(); core_num_wrps = get_num_wrps(); + cpu_notifier_register_begin(); + /* * We need to tread carefully here because DBGSWENABLE may be * driven low on this core and there isn't an architected way to @@ -1089,6 +1091,7 @@ static int __init arch_hw_breakpoint_init(void) if (!cpumask_empty(&debug_err_mask)) { core_num_brps = 0; core_num_wrps = 0; + cpu_notifier_register_done(); return 0; } @@ -1108,7 +1111,10 @@ static int __init arch_hw_breakpoint_init(void) TRAP_HWBKPT, "breakpoint debug exception"); /* Register hotplug and PM notifiers. */ - register_cpu_notifier(&dbg_reset_nb); + __register_cpu_notifier(&dbg_reset_nb); + + cpu_notifier_register_done(); + pm_init(); return 0; } diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index bd18bb8b2770..f0e50a0f3a65 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -1051,21 +1051,26 @@ int kvm_arch_init(void *opaque) } } + cpu_notifier_register_begin(); + err = init_hyp_mode(); if (err) goto out_err; - err = register_cpu_notifier(&hyp_init_cpu_nb); + err = __register_cpu_notifier(&hyp_init_cpu_nb); if (err) { kvm_err("Cannot register HYP init CPU notifier (%d)\n", err); goto out_err; } + cpu_notifier_register_done(); + hyp_cpu_pm_init(); kvm_coproc_table_init(); return 0; out_err: + cpu_notifier_register_done(); return err; } diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c index 14ba23c61153..ed3955a95747 100644 --- a/arch/arm64/kernel/debug-monitors.c +++ b/arch/arm64/kernel/debug-monitors.c @@ -154,13 +154,17 @@ static struct notifier_block os_lock_nb = { static int debug_monitors_init(void) { + cpu_notifier_register_begin(); + /* Clear the OS lock. */ on_each_cpu(clear_os_lock, NULL, 1); isb(); local_dbg_enable(); /* Register hotplug handler. */ - register_cpu_notifier(&os_lock_nb); + __register_cpu_notifier(&os_lock_nb); + + cpu_notifier_register_done(); return 0; } postcore_initcall(debug_monitors_init); diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index f17f581116fc..bee789757806 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -913,6 +913,8 @@ static int __init arch_hw_breakpoint_init(void) pr_info("found %d breakpoint and %d watchpoint registers.\n", core_num_brps, core_num_wrps); + cpu_notifier_register_begin(); + /* * Reset the breakpoint resources. We assume that a halting * debugger will leave the world in a nice state for us. @@ -927,7 +929,10 @@ static int __init arch_hw_breakpoint_init(void) TRAP_HWBKPT, "hw-watchpoint handler"); /* Register hotplug notifier. */ - register_cpu_notifier(&hw_breakpoint_reset_nb); + __register_cpu_notifier(&hw_breakpoint_reset_nb); + + cpu_notifier_register_done(); + /* Register cpu_suspend hw breakpoint restore hook */ cpu_suspend_set_dbg_restorer(hw_breakpoint_reset); diff --git a/arch/ia64/kernel/err_inject.c b/arch/ia64/kernel/err_inject.c index f59c0b844e88..0c161ed6d18e 100644 --- a/arch/ia64/kernel/err_inject.c +++ b/arch/ia64/kernel/err_inject.c @@ -269,12 +269,17 @@ err_inject_init(void) #ifdef ERR_INJ_DEBUG printk(KERN_INFO "Enter error injection driver.\n"); #endif + + cpu_notifier_register_begin(); + for_each_online_cpu(i) { err_inject_cpu_callback(&err_inject_cpu_notifier, CPU_ONLINE, (void *)(long)i); } - register_hotcpu_notifier(&err_inject_cpu_notifier); + __register_hotcpu_notifier(&err_inject_cpu_notifier); + + cpu_notifier_register_done(); return 0; } @@ -288,11 +293,17 @@ err_inject_exit(void) #ifdef ERR_INJ_DEBUG printk(KERN_INFO "Exit error injection driver.\n"); #endif + + cpu_notifier_register_begin(); + for_each_online_cpu(i) { sys_dev = get_cpu_device(i); sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group); } - unregister_hotcpu_notifier(&err_inject_cpu_notifier); + + __unregister_hotcpu_notifier(&err_inject_cpu_notifier); + + cpu_notifier_register_done(); } module_init(err_inject_init); diff --git a/arch/ia64/kernel/palinfo.c b/arch/ia64/kernel/palinfo.c index ab333284f4b2..c39c3cd3ac34 100644 --- a/arch/ia64/kernel/palinfo.c +++ b/arch/ia64/kernel/palinfo.c @@ -996,13 +996,17 @@ palinfo_init(void) if (!palinfo_dir) return -ENOMEM; + cpu_notifier_register_begin(); + /* Create palinfo dirs in /proc for all online cpus */ for_each_online_cpu(i) { create_palinfo_proc_entries(i); } /* Register for future delivery via notify registration */ - register_hotcpu_notifier(&palinfo_cpu_notifier); + __register_hotcpu_notifier(&palinfo_cpu_notifier); + + cpu_notifier_register_done(); return 0; } diff --git a/arch/ia64/kernel/salinfo.c b/arch/ia64/kernel/salinfo.c index 960a396f5929..ee9719eebb1e 100644 --- a/arch/ia64/kernel/salinfo.c +++ b/arch/ia64/kernel/salinfo.c @@ -635,6 +635,8 @@ salinfo_init(void) (void *)salinfo_entries[i].feature); } + cpu_notifier_register_begin(); + for (i = 0; i < ARRAY_SIZE(salinfo_log_name); i++) { data = salinfo_data + i; data->type = i; @@ -669,7 +671,9 @@ salinfo_init(void) salinfo_timer.function = &salinfo_timeout; add_timer(&salinfo_timer); - register_hotcpu_notifier(&salinfo_cpu_notifier); + __register_hotcpu_notifier(&salinfo_cpu_notifier); + + cpu_notifier_register_done(); return 0; } diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c index ca69a5a96dcc..f295f9abba4b 100644 --- a/arch/ia64/kernel/topology.c +++ b/arch/ia64/kernel/topology.c @@ -454,12 +454,16 @@ static int __init cache_sysfs_init(void) { int i; + cpu_notifier_register_begin(); + for_each_online_cpu(i) { struct device *sys_dev = get_cpu_device((unsigned int)i); cache_add_dev(sys_dev); } - register_hotcpu_notifier(&cache_cpu_notifier); + __register_hotcpu_notifier(&cache_cpu_notifier); + + cpu_notifier_register_done(); return 0; } diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c index 97e1dc917683..d90d4b7810d6 100644 --- a/arch/powerpc/kernel/sysfs.c +++ b/arch/powerpc/kernel/sysfs.c @@ -975,7 +975,8 @@ static int __init topology_init(void) int cpu; register_nodes(); - register_cpu_notifier(&sysfs_cpu_nb); + + cpu_notifier_register_begin(); for_each_possible_cpu(cpu) { struct cpu *c = &per_cpu(cpu_devices, cpu); @@ -999,6 +1000,11 @@ static int __init topology_init(void) if (cpu_online(cpu)) register_cpu_online(cpu); } + + __register_cpu_notifier(&sysfs_cpu_nb); + + cpu_notifier_register_done(); + #ifdef CONFIG_PPC64 sysfs_create_dscr_default(); #endif /* CONFIG_PPC64 */ diff --git a/arch/s390/kernel/cache.c b/arch/s390/kernel/cache.c index 3a414c0f93ed..c0b03c28d157 100644 --- a/arch/s390/kernel/cache.c +++ b/arch/s390/kernel/cache.c @@ -378,9 +378,12 @@ static int __init cache_init(void) if (!test_facility(34)) return 0; cache_build_info(); + + cpu_notifier_register_begin(); for_each_online_cpu(cpu) cache_add_cpu(cpu); - hotcpu_notifier(cache_hotplug, 0); + __hotcpu_notifier(cache_hotplug, 0); + cpu_notifier_register_done(); return 0; } device_initcall(cache_init); diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 8827883310dd..5a640b395bd4 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -1057,19 +1057,24 @@ static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); static int __init s390_smp_init(void) { - int cpu, rc; + int cpu, rc = 0; - hotcpu_notifier(smp_cpu_notify, 0); #ifdef CONFIG_HOTPLUG_CPU rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); if (rc) return rc; #endif + cpu_notifier_register_begin(); for_each_present_cpu(cpu) { rc = smp_add_present_cpu(cpu); if (rc) - return rc; + goto out; } - return 0; + + __hotcpu_notifier(smp_cpu_notify, 0); + +out: + cpu_notifier_register_done(); + return rc; } subsys_initcall(s390_smp_init); diff --git a/arch/sparc/kernel/sysfs.c b/arch/sparc/kernel/sysfs.c index c21c673e5f7c..a364000ca1aa 100644 --- a/arch/sparc/kernel/sysfs.c +++ b/arch/sparc/kernel/sysfs.c @@ -300,7 +300,7 @@ static int __init topology_init(void) check_mmu_stats(); - register_cpu_notifier(&sysfs_cpu_nb); + cpu_notifier_register_begin(); for_each_possible_cpu(cpu) { struct cpu *c = &per_cpu(cpu_devices, cpu); @@ -310,6 +310,10 @@ static int __init topology_init(void) register_cpu_online(cpu); } + __register_cpu_notifier(&sysfs_cpu_nb); + + cpu_notifier_register_done(); + return 0; } diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c index 0641113e2965..a952e9c85b6f 100644 --- a/arch/x86/kernel/cpu/intel_cacheinfo.c +++ b/arch/x86/kernel/cpu/intel_cacheinfo.c @@ -1225,21 +1225,24 @@ static struct notifier_block cacheinfo_cpu_notifier = { static int __init cache_sysfs_init(void) { - int i; + int i, err = 0; if (num_cache_leaves == 0) return 0; + cpu_notifier_register_begin(); for_each_online_cpu(i) { - int err; struct device *dev = get_cpu_device(i); err = cache_add_dev(dev); if (err) - return err; + goto out; } - register_hotcpu_notifier(&cacheinfo_cpu_notifier); - return 0; + __register_hotcpu_notifier(&cacheinfo_cpu_notifier); + +out: + cpu_notifier_register_done(); + return err; } device_initcall(cache_sysfs_init); diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 4d5419b249da..9b7734b1f975 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -2434,14 +2434,18 @@ static __init int mcheck_init_device(void) if (err) return err; + cpu_notifier_register_begin(); for_each_online_cpu(i) { err = mce_device_create(i); - if (err) + if (err) { + cpu_notifier_register_done(); return err; + } } register_syscore_ops(&mce_syscore_ops); - register_hotcpu_notifier(&mce_cpu_notifier); + __register_hotcpu_notifier(&mce_cpu_notifier); + cpu_notifier_register_done(); /* register character device /dev/mcelog */ misc_register(&mce_chrdev_device); diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c index 3eec7de76efb..d921b7ee6595 100644 --- a/arch/x86/kernel/cpu/mcheck/therm_throt.c +++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c @@ -271,9 +271,6 @@ static void thermal_throttle_remove_dev(struct device *dev) sysfs_remove_group(&dev->kobj, &thermal_attr_group); } -/* Mutex protecting device creation against CPU hotplug: */ -static DEFINE_MUTEX(therm_cpu_lock); - /* Get notified when a cpu comes on/off. Be hotplug friendly. */ static int thermal_throttle_cpu_callback(struct notifier_block *nfb, @@ -289,18 +286,14 @@ thermal_throttle_cpu_callback(struct notifier_block *nfb, switch (action) { case CPU_UP_PREPARE: case CPU_UP_PREPARE_FROZEN: - mutex_lock(&therm_cpu_lock); err = thermal_throttle_add_dev(dev, cpu); - mutex_unlock(&therm_cpu_lock); WARN_ON(err); break; case CPU_UP_CANCELED: case CPU_UP_CANCELED_FROZEN: case CPU_DEAD: case CPU_DEAD_FROZEN: - mutex_lock(&therm_cpu_lock); thermal_throttle_remove_dev(dev); - mutex_unlock(&therm_cpu_lock); break; } return notifier_from_errno(err); @@ -319,19 +312,16 @@ static __init int thermal_throttle_init_device(void) if (!atomic_read(&therm_throt_en)) return 0; - register_hotcpu_notifier(&thermal_throttle_cpu_notifier); + cpu_notifier_register_begin(); -#ifdef CONFIG_HOTPLUG_CPU - mutex_lock(&therm_cpu_lock); -#endif /* connect live CPUs to sysfs */ for_each_online_cpu(cpu) { err = thermal_throttle_add_dev(get_cpu_device(cpu), cpu); WARN_ON(err); } -#ifdef CONFIG_HOTPLUG_CPU - mutex_unlock(&therm_cpu_lock); -#endif + + __register_hotcpu_notifier(&thermal_throttle_cpu_notifier); + cpu_notifier_register_done(); return 0; } diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c index 4b8e4d3cd6ea..4c36bbe3173a 100644 --- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c +++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c @@ -926,13 +926,13 @@ static __init int amd_ibs_init(void) goto out; perf_ibs_pm_init(); - get_online_cpus(); + cpu_notifier_register_begin(); ibs_caps = caps; /* make ibs_caps visible to other cpus: */ smp_mb(); - perf_cpu_notifier(perf_ibs_cpu_notifier); smp_call_function(setup_APIC_ibs, NULL, 1); - put_online_cpus(); + __perf_cpu_notifier(perf_ibs_cpu_notifier); + cpu_notifier_register_done(); ret = perf_event_ibs_init(); out: diff --git a/arch/x86/kernel/cpu/perf_event_amd_uncore.c b/arch/x86/kernel/cpu/perf_event_amd_uncore.c index 754291adec33..3bbdf4cd38b9 100644 --- a/arch/x86/kernel/cpu/perf_event_amd_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_amd_uncore.c @@ -531,15 +531,16 @@ static int __init amd_uncore_init(void) if (ret) return -ENODEV; - get_online_cpus(); + cpu_notifier_register_begin(); + /* init cpus already online before registering for hotplug notifier */ for_each_online_cpu(cpu) { amd_uncore_cpu_up_prepare(cpu); smp_call_function_single(cpu, init_cpu_already_online, NULL, 1); } - register_cpu_notifier(&amd_uncore_cpu_notifier_block); - put_online_cpus(); + __register_cpu_notifier(&amd_uncore_cpu_notifier_block); + cpu_notifier_register_done(); return 0; } diff --git a/arch/x86/kernel/cpu/perf_event_intel_rapl.c b/arch/x86/kernel/cpu/perf_event_intel_rapl.c index 5ad35ad94d0f..059218ed5208 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c +++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c @@ -646,19 +646,20 @@ static int __init rapl_pmu_init(void) /* unsupported */ return 0; } - get_online_cpus(); + + cpu_notifier_register_begin(); for_each_online_cpu(cpu) { rapl_cpu_prepare(cpu); rapl_cpu_init(cpu); } - perf_cpu_notifier(rapl_cpu_notifier); + __perf_cpu_notifier(rapl_cpu_notifier); ret = perf_pmu_register(&rapl_pmu_class, "power", -1); if (WARN_ON(ret)) { pr_info("RAPL PMU detected, registration failed (%d), RAPL PMU disabled\n", ret); - put_online_cpus(); + cpu_notifier_register_done(); return -1; } @@ -672,7 +673,7 @@ static int __init rapl_pmu_init(void) hweight32(rapl_cntr_mask), ktime_to_ms(pmu->timer_interval)); - put_online_cpus(); + cpu_notifier_register_done(); return 0; } diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c index bd2253d40cff..65bbbea38b9c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -4244,7 +4244,7 @@ static void __init uncore_cpumask_init(void) if (!cpumask_empty(&uncore_cpu_mask)) return; - get_online_cpus(); + cpu_notifier_register_begin(); for_each_online_cpu(cpu) { int i, phys_id = topology_physical_package_id(cpu); @@ -4263,9 +4263,9 @@ static void __init uncore_cpumask_init(void) } on_each_cpu(uncore_cpu_setup, NULL, 1); - register_cpu_notifier(&uncore_cpu_nb); + __register_cpu_notifier(&uncore_cpu_nb); - put_online_cpus(); + cpu_notifier_register_done(); } diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c index 7d9481c743f8..3225ae6c5180 100644 --- a/arch/x86/kernel/cpuid.c +++ b/arch/x86/kernel/cpuid.c @@ -198,14 +198,15 @@ static int __init cpuid_init(void) goto out_chrdev; } cpuid_class->devnode = cpuid_devnode; - get_online_cpus(); + + cpu_notifier_register_begin(); for_each_online_cpu(i) { err = cpuid_device_create(i); if (err != 0) goto out_class; } - register_hotcpu_notifier(&cpuid_class_cpu_notifier); - put_online_cpus(); + __register_hotcpu_notifier(&cpuid_class_cpu_notifier); + cpu_notifier_register_done(); err = 0; goto out; @@ -215,7 +216,7 @@ out_class: for_each_online_cpu(i) { cpuid_device_destroy(i); } - put_online_cpus(); + cpu_notifier_register_done(); class_destroy(cpuid_class); out_chrdev: __unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid"); @@ -227,13 +228,13 @@ static void __exit cpuid_exit(void) { int cpu = 0; - get_online_cpus(); + cpu_notifier_register_begin(); for_each_online_cpu(cpu) cpuid_device_destroy(cpu); class_destroy(cpuid_class); __unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid"); - unregister_hotcpu_notifier(&cpuid_class_cpu_notifier); - put_online_cpus(); + __unregister_hotcpu_notifier(&cpuid_class_cpu_notifier); + cpu_notifier_register_done(); } module_init(cpuid_init); diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 93eed15a8fd4..8d80ae011603 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -941,12 +941,14 @@ static __init int hpet_late_init(void) if (boot_cpu_has(X86_FEATURE_ARAT)) return 0; + cpu_notifier_register_begin(); for_each_online_cpu(cpu) { hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu); } /* This notifier should be called after workqueue is ready */ - hotcpu_notifier(hpet_cpuhp_notify, -20); + __hotcpu_notifier(hpet_cpuhp_notify, -20); + cpu_notifier_register_done(); return 0; } diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index 05266b5aae22..c9603ac80de5 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -259,14 +259,15 @@ static int __init msr_init(void) goto out_chrdev; } msr_class->devnode = msr_devnode; - get_online_cpus(); + + cpu_notifier_register_begin(); for_each_ |