diff options
| author | Mike Galbraith <umgwanakikbuti@gmail.com> | 2015-04-11 15:15:59 +0200 |
|---|---|---|
| committer | Anders Roxell <anders.roxell@linaro.org> | 2015-06-24 21:13:07 +0200 |
| commit | d19f4a7b6c71103c06607f2278df08f6bc1516ab (patch) | |
| tree | 4f4a2b1f24a156066c9befd90e1987eed4af2089 | |
| parent | 76b3c34d7005b9676108232a5c0191494427be62 (diff) | |
rt, nohz_full: fix nohz_full for PREEMPT_RT_FULL
A task being ticked and trying to shut the tick down will fail due
to having just awakened ksoftirqd, subtract it from nr_running.
Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | kernel/sched/core.c | 17 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 5 |
2 files changed, 21 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 93653e6e0ed4..be8af39900f7 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -754,14 +754,29 @@ static inline bool got_nohz_idle_kick(void) #endif /* CONFIG_NO_HZ_COMMON */ #ifdef CONFIG_NO_HZ_FULL + +static int ksoftirqd_running(void) +{ + struct task_struct *softirqd; + + if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) + return 0; + softirqd = this_cpu_ksoftirqd(); + if (softirqd && softirqd->on_rq) + return 1; + return 0; +} + bool sched_can_stop_tick(void) { /* * More than one running task need preemption. * nr_running update is assumed to be visible * after IPI is sent from wakers. + * + * NOTE, RT: if ksoftirqd is awake, subtract it. */ - if (this_rq()->nr_running > 1) + if (this_rq()->nr_running - ksoftirqd_running() > 1) return false; return true; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 3a43989f0ce0..d7cef36a443c 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -227,7 +227,12 @@ void __tick_nohz_full_check(void) static void nohz_full_kick_work_func(struct irq_work *work) { + unsigned long flags; + + /* ksoftirqd processes sirqs with interrupts enabled */ + local_irq_save(flags); __tick_nohz_full_check(); + local_irq_restore(flags); } static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = { |