diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2018-12-11 12:12:38 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-01-25 15:36:42 -0800 |
| commit | e81baf4cb19a9b428ba477fd0423f81672a58817 (patch) | |
| tree | fd518df0bf3f31968c4541ff488f0c727cc1b2b2 /kernel/rcu/tree.h | |
| parent | c8ca1aa774b20f182733d1661f3b6aa3105338e7 (diff) | |
srcu: Remove srcu_queue_delayed_work_on()
srcu_queue_delayed_work_on() disables preemption (and therefore CPU
hotplug in RCU's case) and then checks based on its own accounting if a
CPU is online. If the CPU is online it uses queue_delayed_work_on()
otherwise it fallbacks to queue_delayed_work().
The problem here is that queue_work() on -RT does not work with disabled
preemption.
queue_work_on() works also on an offlined CPU. queue_delayed_work_on()
has the problem that it is possible to program a timer on an offlined
CPU. This timer will fire once the CPU is online again. But until then,
the timer remains programmed and nothing will happen.
Add a local timer which will fire (as requested per delay) on the local
CPU and then enqueue the work on the specific CPU.
RCUtorture testing with SRCU-P for 24h showed no problems.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/rcu/tree.h')
| -rw-r--r-- | kernel/rcu/tree.h | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 149557b7c39c..4bba017c703c 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -458,11 +458,3 @@ static void rcu_bind_gp_kthread(void); static bool rcu_nohz_full_cpu(void); static void rcu_dynticks_task_enter(void); static void rcu_dynticks_task_exit(void); - -#ifdef CONFIG_SRCU -void srcu_online_cpu(unsigned int cpu); -void srcu_offline_cpu(unsigned int cpu); -#else /* #ifdef CONFIG_SRCU */ -void srcu_online_cpu(unsigned int cpu) { } -void srcu_offline_cpu(unsigned int cpu) { } -#endif /* #else #ifdef CONFIG_SRCU */ |