On 2017-12-18 20:01:05 [-0600], Grygorii Strashko wrote:
> Hi All,
Hi,
> Below results of running stress-ng --class os --all 0 -t 5m on TI am57xx-evm
> (SMP, 2 cpu)
> git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
> branch: linux-4.14.y-rt
> commit: d3d9904 v4.14.6-rt7
> - only config changes applied.
>
> one "WARNING: possible circular locking dependency detected"
> [ 85.943562] ======================================================
> [ 85.943564] WARNING: possible circular locking dependency detected
> [ 85.943568] 4.14.6-rt7-dirty #29 Not tainted
> [ 85.943570] ------------------------------------------------------
> [ 85.943573] stress-ng-cpu-o/764 is trying to acquire lock:
> [ 85.943576] (&p->pi_lock){-...}, at: [<c0169ce8>]
> try_to_wake_up+0x28/0x924
> [ 85.943594]
> [ 85.943594] but task is already holding lock:
> [ 85.943596] (hrtimer_bases.lock){-...}, at: [<c01c12ac>]
> hrtimer_interrupt+0x68/0x2b0
>
> one "WARNING: CPU: 0 PID: 3514 at kernel/rcu/tree_plugin.h:310
> rcu_note_context_switch+0x3e8/0x988"
> ^ sorry, log not very readable
This should cure it, does it?
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index c2c344fda487..3971fa0c7194 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1952,6 +1952,7 @@ int hrtimers_dead_cpu(unsigned int scpu)
BUG_ON(cpu_online(scpu));
tick_cancel_sched_timer(scpu);
+ local_bh_disable();
local_irq_disable();
old_base = &per_cpu(hrtimer_bases, scpu);
new_base = this_cpu_ptr(&hrtimer_bases);
@@ -1979,6 +1980,7 @@ int hrtimers_dead_cpu(unsigned int scpu)
/* Check, if we got expired work to do */
__hrtimer_peek_ahead_timers();
local_irq_enable();
+ local_bh_enable();
return 0;
}
Sebastian
