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authorPeter Zijlstra <peterz@infradead.org>2015-03-31 20:49:02 +0530
committerIngo Molnar <mingo@kernel.org>2015-04-02 17:46:21 +0200
commit3650b57fdf208bc0e36cbe7b5e0744bd0e0cf34d (patch)
treee62223fe5b72899adc985709b716587e404cc61b /kernel/time/timer.c
parent8def906044c02edcedac79aa3d6310ab4d90c4d8 (diff)
downloadlinux-sh-3650b57fdf208bc0e36cbe7b5e0744bd0e0cf34d.tar.gz
timer: Further simplify the SMP and HOTPLUG logic
Remove one CONFIG_HOTPLUG_CPU #ifdef in trade for introducing one CONFIG_SMP #ifdef. The CONFIG_SMP ifdef avoids declaring the per-CPU __tvec_bases storage on UP systems since they already have boot_tvec_bases. Also (re)add a runtime check on the base alignment -- for the paranoid amongst us :-) Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/fdd2d35e169bdc554ffa3fe77f77716298c75ada.1427814611.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/time/timer.c')
-rw-r--r--kernel/time/timer.c23
1 files changed, 15 insertions, 8 deletions
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 1feb9c7035c0..2ece3aa5069c 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -101,7 +101,6 @@ struct tvec_base {
*/
struct tvec_base boot_tvec_bases;
EXPORT_SYMBOL(boot_tvec_bases);
-static DEFINE_PER_CPU(struct tvec_base, __tvec_bases);
static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases;
@@ -1038,6 +1037,8 @@ int try_to_del_timer_sync(struct timer_list *timer)
EXPORT_SYMBOL(try_to_del_timer_sync);
#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct tvec_base, __tvec_bases);
+
/**
* del_timer_sync - deactivate a timer and wait for the handler to finish.
* @timer: the timer to be deactivated
@@ -1591,12 +1592,10 @@ static void migrate_timers(int cpu)
spin_unlock_irq(&new_base->lock);
put_cpu_var(tvec_bases);
}
-#endif /* CONFIG_HOTPLUG_CPU */
static int timer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
-#ifdef CONFIG_HOTPLUG_CPU
switch (action) {
case CPU_DEAD:
case CPU_DEAD_FROZEN:
@@ -1605,18 +1604,24 @@ static int timer_cpu_notify(struct notifier_block *self,
default:
break;
}
-#endif
+
return NOTIFY_OK;
}
-static struct notifier_block timers_nb = {
- .notifier_call = timer_cpu_notify,
-};
+static inline void timer_register_cpu_notifier(void)
+{
+ cpu_notifier(timer_cpu_notify, 0);
+}
+#else
+static inline void timer_register_cpu_notifier(void) { }
+#endif /* CONFIG_HOTPLUG_CPU */
static void __init init_timer_cpu(struct tvec_base *base, int cpu)
{
int j;
+ BUG_ON(base != tbase_get_base(base));
+
base->cpu = cpu;
per_cpu(tvec_bases, cpu) = base;
spin_lock_init(&base->lock);
@@ -1643,8 +1648,10 @@ static void __init init_timer_cpus(void)
for_each_possible_cpu(cpu) {
if (cpu == local_cpu)
base = &boot_tvec_bases;
+#ifdef CONFIG_SMP
else
base = per_cpu_ptr(&__tvec_bases, cpu);
+#endif
init_timer_cpu(base, cpu);
}
@@ -1657,7 +1664,7 @@ void __init init_timers(void)
init_timer_cpus();
init_timer_stats();
- register_cpu_notifier(&timers_nb);
+ timer_register_cpu_notifier();
open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
}