Commit-ID: 31eff2434db542763a00074a8368d7bd78d14ea1 Gitweb: http://git.kernel.org/tip/31eff2434db542763a00074a8368d7bd78d14ea1 Author: Sebastian Andrzej Siewior <bige...@linutronix.de> AuthorDate: Thu, 17 Nov 2016 19:35:34 +0100 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Tue, 22 Nov 2016 23:34:41 +0100
sched/nohz: Convert to hotplug state machine Install the callbacks via the state machine. Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de> Cc: r...@linuxtronix.de Link: http://lkml.kernel.org/r/20161117183541.8588-14-bige...@linutronix.de Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- kernel/time/tick-sched.c | 33 ++++++++++++++------------------- 1 file changed, 14 insertions(+), 19 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 3bcb61b..71496a2 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -390,24 +390,16 @@ static int __init tick_nohz_full_setup(char *str) } __setup("nohz_full=", tick_nohz_full_setup); -static int tick_nohz_cpu_down_callback(struct notifier_block *nfb, - unsigned long action, - void *hcpu) +static int tick_nohz_cpu_down(unsigned int cpu) { - unsigned int cpu = (unsigned long)hcpu; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_DOWN_PREPARE: - /* - * The boot CPU handles housekeeping duty (unbound timers, - * workqueues, timekeeping, ...) on behalf of full dynticks - * CPUs. It must remain online when nohz full is enabled. - */ - if (tick_nohz_full_running && tick_do_timer_cpu == cpu) - return NOTIFY_BAD; - break; - } - return NOTIFY_OK; + /* + * The boot CPU handles housekeeping duty (unbound timers, + * workqueues, timekeeping, ...) on behalf of full dynticks + * CPUs. It must remain online when nohz full is enabled. + */ + if (tick_nohz_full_running && tick_do_timer_cpu == cpu) + return -EBUSY; + return 0; } static int tick_nohz_init_all(void) @@ -428,7 +420,7 @@ static int tick_nohz_init_all(void) void __init tick_nohz_init(void) { - int cpu; + int cpu, ret; if (!tick_nohz_full_running) { if (tick_nohz_init_all() < 0) @@ -469,7 +461,10 @@ void __init tick_nohz_init(void) for_each_cpu(cpu, tick_nohz_full_mask) context_tracking_cpu_set(cpu); - cpu_notifier(tick_nohz_cpu_down_callback, 0); + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, + "kernel/nohz:predown", NULL, + tick_nohz_cpu_down); + WARN_ON(ret < 0); pr_info("NO_HZ: Full dynticks CPUs: %*pbl.\n", cpumask_pr_args(tick_nohz_full_mask));
