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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-11-17 19:35:34 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-11-22 23:34:41 +0100 |
| commit | 31eff2434db542763a00074a8368d7bd78d14ea1 (patch) | |
| tree | bca062834d5098723d4d31428346a8bf23eb1de1 /kernel/time/tick-sched.c | |
| parent | net/iucv: Convert to hotplug state machine (diff) | |
| download | linux-31eff2434db542763a00074a8368d7bd78d14ea1.tar.xz linux-31eff2434db542763a00074a8368d7bd78d14ea1.zip | |
sched/nohz: Convert to hotplug state machine
Install the callbacks via the state machine.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: rt@linuxtronix.de
Link: http://lkml.kernel.org/r/20161117183541.8588-14-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time/tick-sched.c')
| -rw-r--r-- | kernel/time/tick-sched.c | 33 |
1 files changed, 14 insertions, 19 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 3bcb61b52f6c..71496a20e670 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)); |