Re: v4.11.12-rt10 - hotplug lockdep splat
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2017-08-31 16:18:37
Also in:
lkml
Subsystem:
high-resolution timers, timer wheel, clockevents, the rest · Maintainers:
Anna-Maria Behnsen, Frederic Weisbecker, Thomas Gleixner, Linus Torvalds
On 2017-08-23 11:53:44 [+0200], Mike Galbraith wrote:
virt box reminded me this morning to report this gripe.
if you can reproduce it, then this should make it go away:
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c@@ -1391,7 +1391,7 @@ static inline int hrtimer_rt_defer(struct hrtimer *timer) { return 0; } #endif -static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now) +static int __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now) { struct hrtimer_clock_base *base = cpu_base->clock_base; unsigned int active = cpu_base->active_bases;
@@ -1432,8 +1432,7 @@ static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now) raise = 1; } } - if (raise) - raise_softirq_irqoff(HRTIMER_SOFTIRQ); + return raise; } #ifdef CONFIG_HIGH_RES_TIMERS
@@ -1447,6 +1446,7 @@ void hrtimer_interrupt(struct clock_event_device *dev) struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); ktime_t expires_next, now, entry_time, delta; int retries = 0; + int raise; BUG_ON(!cpu_base->hres_active); cpu_base->nr_events++;
@@ -1465,7 +1465,7 @@ void hrtimer_interrupt(struct clock_event_device *dev) */ cpu_base->expires_next = KTIME_MAX; - __hrtimer_run_queues(cpu_base, now); + raise = __hrtimer_run_queues(cpu_base, now); /* Reevaluate the clock bases for the next expiry */ expires_next = __hrtimer_get_next_event(cpu_base);
@@ -1476,6 +1476,8 @@ void hrtimer_interrupt(struct clock_event_device *dev) cpu_base->expires_next = expires_next; cpu_base->in_hrtirq = 0; raw_spin_unlock(&cpu_base->lock); + if (raise) + raise_softirq_irqoff(HRTIMER_SOFTIRQ); /* Reprogramming necessary ? */ if (!tick_program_event(expires_next, 0)) {
@@ -1555,6 +1557,7 @@ void hrtimer_run_queues(void) { struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); ktime_t now; + int raise; if (__hrtimer_hres_active(cpu_base)) return;
@@ -1573,8 +1576,10 @@ void hrtimer_run_queues(void) raw_spin_lock(&cpu_base->lock); now = hrtimer_update_base(cpu_base); - __hrtimer_run_queues(cpu_base, now); + raise = __hrtimer_run_queues(cpu_base, now); raw_spin_unlock(&cpu_base->lock); + if (raise) + raise_softirq_irqoff(HRTIMER_SOFTIRQ); } /*
Sebastian