Commit-ID: 931ef163309ee955611f287dc65248b39a65fc9d Gitweb: http://git.kernel.org/tip/931ef163309ee955611f287dc65248b39a65fc9d Author: Thomas Gleixner <[email protected]> AuthorDate: Fri, 26 Feb 2016 18:43:36 +0000 Committer: Thomas Gleixner <[email protected]> CommitDate: Tue, 1 Mar 2016 20:36:56 +0100
cpu/hotplug: Unpark smpboot threads from the state machine Handle the smpboot threads in the state machine. Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: Rik van Riel <[email protected]> Cc: Rafael Wysocki <[email protected]> Cc: "Srivatsa S. Bhat" <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Arjan van de Ven <[email protected]> Cc: Sebastian Siewior <[email protected]> Cc: Rusty Russell <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Paul McKenney <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul Turner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]> --- 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(-) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 78989f2..83f3576 100644 --- 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_notifier(struct notifier_block *nb) } #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_done(void) { } -static inline void smpboot_thread_init(void) -{ -} - #endif /* CONFIG_SMP */ extern struct bus_type cpu_subsys; diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 2f2e5d9..3867910 100644 --- 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, diff --git a/init/main.c b/init/main.c index c2ea723..55563fd 100644 --- a/init/main.c +++ b/init/main.c @@ -388,7 +388,6 @@ static noinline void __init_refok rest_init(void) 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 diff --git a/kernel/cpu.c b/kernel/cpu.c index 65e34d3..3ec86bc 100644 --- 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, diff --git a/kernel/smpboot.c b/kernel/smpboot.c index d264f59..13bc43d 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -226,7 +226,7 @@ static void smpboot_unpark_thread(struct smp_hotplug_thread *ht, unsigned int cp 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 cpu) 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 smp_hotplug_thread *ht, unsigned int cpu) 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 cpu) 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) diff --git a/kernel/smpboot.h b/kernel/smpboot.h index 72415a0..6b5f020 100644 --- a/kernel/smpboot.h +++ b/kernel/smpboot.h @@ -14,7 +14,7 @@ static inline void idle_threads_init(void) { } #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
