From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423141AbcBZSqe (ORCPT ); Fri, 26 Feb 2016 13:46:34 -0500 Received: from www.linutronix.de ([62.245.132.108]:33449 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423035AbcBZSpN (ORCPT ); Fri, 26 Feb 2016 13:45:13 -0500 Message-Id: <20160226182341.295777684@linutronix.de> User-Agent: quilt/0.63-1 Date: Fri, 26 Feb 2016 18:43:36 -0000 From: Thomas Gleixner To: LKML Cc: Linus Torvalds , Andrew Morton , Ingo Molnar , Peter Zijlstra , Peter Anvin , Oleg Nesterov , linux-arch@vger.kernel.org, Tejun Heo , Steven Rostedt , Rusty Russell , Paul McKenney , Rafael Wysocki , Arjan van de Ven , Rik van Riel , "Srivatsa S. Bhat" , Sebastian Siewior , Paul Turner Subject: [patch 13/20] cpu/hotplug: Unpark smpboot threads from the state machine References: <20160226164321.657646833@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=hotplug--Handle-smpboot-threads-in-state-machine.patch X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001,URIBL_BLOCKED=0.001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Handle the smpboot threads in the state machine. Signed-off-by: Thomas Gleixner --- include/linux/cpu.h | 7 +------ include/linux/cpuhotplug.h | 1 + init/main.c | 1 - kernel/cpu.c | 39 +++++---------------------------------- kernel/smpboot.c | 6 ++++-- kernel/smpboot.h | 4 ++-- 6 files changed, 13 insertions(+), 45 deletions(-) Index: b/include/linux/cpu.h =================================================================== --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -78,7 +78,7 @@ enum { /* migration should happen before other stuff but after perf */ CPU_PRI_PERF = 20, CPU_PRI_MIGRATION = 10, - CPU_PRI_SMPBOOT = 9, + /* bring up workqueues before normal notifiers and down after */ CPU_PRI_WORKQUEUE_UP = 5, CPU_PRI_WORKQUEUE_DOWN = -5, @@ -172,7 +172,6 @@ static inline void __unregister_cpu_noti } #endif -void smpboot_thread_init(void); int cpu_up(unsigned int cpu); void notify_cpu_starting(unsigned int cpu); extern void cpu_maps_update_begin(void); @@ -221,10 +220,6 @@ static inline void cpu_notifier_register { } -static inline void smpboot_thread_init(void) -{ -} - #endif /* CONFIG_SMP */ extern struct bus_type cpu_subsys; Index: b/include/linux/cpuhotplug.h =================================================================== --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -11,6 +11,7 @@ enum cpuhp_state { CPUHP_AP_ONLINE, CPUHP_TEARDOWN_CPU, CPUHP_CPU_SET_ACTIVE, + CPUHP_SMPBOOT_THREADS, CPUHP_NOTIFY_ONLINE, CPUHP_ONLINE_DYN, CPUHP_ONLINE_DYN_END = CPUHP_ONLINE_DYN + 30, Index: b/init/main.c =================================================================== --- a/init/main.c +++ b/init/main.c @@ -388,7 +388,6 @@ static noinline void __init_refok rest_i int pid; rcu_scheduler_starting(); - smpboot_thread_init(); /* * We need to spawn init first so that it obtains pid 1, however * the init task will end up wanting to create kthreads, which, if Index: b/kernel/cpu.c =================================================================== --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -481,8 +481,6 @@ static int takedown_cpu(unsigned int cpu else synchronize_rcu(); - smpboot_park_threads(cpu); - /* * Prevent irq alloc/free while the dying cpu reorganizes the * interrupt affinities. @@ -612,38 +610,6 @@ int cpu_down(unsigned int cpu) EXPORT_SYMBOL(cpu_down); #endif /*CONFIG_HOTPLUG_CPU*/ -/* - * Unpark per-CPU smpboot kthreads at CPU-online time. - */ -static int smpboot_thread_call(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - int cpu = (long)hcpu; - - switch (action & ~CPU_TASKS_FROZEN) { - - case CPU_DOWN_FAILED: - case CPU_ONLINE: - smpboot_unpark_threads(cpu); - break; - - default: - break; - } - - return NOTIFY_OK; -} - -static struct notifier_block smpboot_thread_notifier = { - .notifier_call = smpboot_thread_call, - .priority = CPU_PRI_SMPBOOT, -}; - -void smpboot_thread_init(void) -{ - register_cpu_notifier(&smpboot_thread_notifier); -} - /** * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers * @cpu: cpu that just started @@ -959,6 +925,11 @@ static struct cpuhp_step cpuhp_bp_states .startup = cpuhp_set_cpu_active, .teardown = NULL, }, + [CPUHP_SMPBOOT_THREADS] = { + .name = "smpboot:threads", + .startup = smpboot_unpark_threads, + .teardown = smpboot_park_threads, + }, [CPUHP_NOTIFY_ONLINE] = { .name = "notify:online", .startup = notify_online, Index: b/kernel/smpboot.c =================================================================== --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -226,7 +226,7 @@ static void smpboot_unpark_thread(struct kthread_unpark(tsk); } -void smpboot_unpark_threads(unsigned int cpu) +int smpboot_unpark_threads(unsigned int cpu) { struct smp_hotplug_thread *cur; @@ -235,6 +235,7 @@ void smpboot_unpark_threads(unsigned int if (cpumask_test_cpu(cpu, cur->cpumask)) smpboot_unpark_thread(cur, cpu); mutex_unlock(&smpboot_threads_lock); + return 0; } static void smpboot_park_thread(struct smp_hotplug_thread *ht, unsigned int cpu) @@ -245,7 +246,7 @@ static void smpboot_park_thread(struct s kthread_park(tsk); } -void smpboot_park_threads(unsigned int cpu) +int smpboot_park_threads(unsigned int cpu) { struct smp_hotplug_thread *cur; @@ -253,6 +254,7 @@ void smpboot_park_threads(unsigned int c list_for_each_entry_reverse(cur, &hotplug_threads, list) smpboot_park_thread(cur, cpu); mutex_unlock(&smpboot_threads_lock); + return 0; } static void smpboot_destroy_threads(struct smp_hotplug_thread *ht) Index: b/kernel/smpboot.h =================================================================== --- a/kernel/smpboot.h +++ b/kernel/smpboot.h @@ -14,7 +14,7 @@ static inline void idle_threads_init(voi #endif int smpboot_create_threads(unsigned int cpu); -void smpboot_park_threads(unsigned int cpu); -void smpboot_unpark_threads(unsigned int cpu); +int smpboot_park_threads(unsigned int cpu); +int smpboot_unpark_threads(unsigned int cpu); #endif