From 27590dc17b34aedc4f3e14bd107ee59b9db9b0a6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 15 Jul 2016 10:41:04 +0200 Subject: [PATCH] hrtimer: Convert to hotplug state machine Split out the clockevents callbacks instead of piggybacking them on hrtimers. This gets rid of a POST_DEAD user. See commit: 54e88fad223c ("sched: Make sure timers have migrated before killing the migration_thread") We just move the callback state to the proper place in the state machine. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Rusty Russell Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.485419196@linutronix.de Signed-off-by: Ingo Molnar --- include/linux/cpuhotplug.h | 1 + include/linux/hrtimer.h | 7 +++++++ kernel/cpu.c | 5 +++++ kernel/time/hrtimer.c | 40 +++++--------------------------------- 4 files changed, 18 insertions(+), 35 deletions(-) diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 070cc7f28862..04ecc55009ed 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -15,6 +15,7 @@ enum cpuhp_state { CPUHP_X86_HPET_DEAD, CPUHP_X86_APB_DEAD, CPUHP_WORKQUEUE_PREP, + CPUHP_HRTIMERS_PREPARE, CPUHP_NOTIFY_PREPARE, CPUHP_BRINGUP_CPU, CPUHP_AP_IDLE_DEAD, diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index c98c6539e2c2..5e00f80b1535 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -494,4 +494,11 @@ extern void __init hrtimers_init(void); /* Show pending timers: */ extern void sysrq_timer_list_show(void); +int hrtimers_prepare_cpu(unsigned int cpu); +#ifdef CONFIG_HOTPLUG_CPU +int hrtimers_dead_cpu(unsigned int cpu); +#else +#define hrtimers_dead_cpu NULL +#endif + #endif diff --git a/kernel/cpu.c b/kernel/cpu.c index af53f820fec9..85500e7fe238 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1190,6 +1190,11 @@ static struct cpuhp_step cpuhp_bp_states[] = { .startup = workqueue_prepare_cpu, .teardown = NULL, }, + [CPUHP_HRTIMERS_PREPARE] = { + .name = "hrtimers prepare", + .startup = hrtimers_prepare_cpu, + .teardown = hrtimers_dead_cpu, + }, /* * Preparatory and dead notifiers. Will be replaced once the notifiers * are converted to states. diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index d13c9aebf7a3..9ba7c820fc23 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1590,7 +1590,7 @@ SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp, /* * Functions related to boot-time initialization: */ -static void init_hrtimers_cpu(int cpu) +int hrtimers_prepare_cpu(unsigned int cpu) { struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); int i; @@ -1602,6 +1602,7 @@ static void init_hrtimers_cpu(int cpu) cpu_base->cpu = cpu; hrtimer_init_hres(cpu_base); + return 0; } #ifdef CONFIG_HOTPLUG_CPU @@ -1636,7 +1637,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, } } -static void migrate_hrtimers(int scpu) +int hrtimers_dead_cpu(unsigned int scpu) { struct hrtimer_cpu_base *old_base, *new_base; int i; @@ -1665,45 +1666,14 @@ static void migrate_hrtimers(int scpu) /* Check, if we got expired work to do */ __hrtimer_peek_ahead_timers(); local_irq_enable(); + return 0; } #endif /* CONFIG_HOTPLUG_CPU */ -static int hrtimer_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - int scpu = (long)hcpu; - - switch (action) { - - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - init_hrtimers_cpu(scpu); - break; - -#ifdef CONFIG_HOTPLUG_CPU - case CPU_DEAD: - case CPU_DEAD_FROZEN: - migrate_hrtimers(scpu); - break; -#endif - - default: - break; - } - - return NOTIFY_OK; -} - -static struct notifier_block hrtimers_nb = { - .notifier_call = hrtimer_cpu_notify, -}; - void __init hrtimers_init(void) { - hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, - (void *)(long)smp_processor_id()); - register_cpu_notifier(&hrtimers_nb); + hrtimers_prepare_cpu(smp_processor_id()); } /** -- 2.30.2