Re: RCU lockup issues when CONFIG_SOFTLOCKUP_DETECTOR=n - any one else seeing this?
From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2017-08-16 12:43:52
Also in:
linux-arm-kernel, sparclinux
Possibly related (same subject, not in this thread)
- 2017-08-01 · RCU lockup issues when CONFIG_SOFTLOCKUP_DETECTOR=n - any one else seeing this? · Jonathan.Cameron@huawei.com (Jonathan Cameron)
- 2017-07-31 · RCU lockup issues when CONFIG_SOFTLOCKUP_DETECTOR=n - any one else seeing this? · Jonathan.Cameron@huawei.com (Jonathan Cameron)
- 2017-07-31 · RCU lockup issues when CONFIG_SOFTLOCKUP_DETECTOR=n - any one else seeing this? · Jonathan.Cameron@huawei.com (Jonathan Cameron)
- 2017-07-30 · RCU lockup issues when CONFIG_SOFTLOCKUP_DETECTOR=n - any one else seeing this? · Paul E. McKenney <hidden>
- 2017-07-30 · RCU lockup issues when CONFIG_SOFTLOCKUP_DETECTOR=n - any one else seeing this? · Boqun Feng <hidden>
"Paul E. McKenney" [off-list ref] writes: ...
quoted hunk ↗ jump to hunk
commit 33103e7b1f89ef432dfe3337d2a6932cdf5c1312 Author: Paul E. McKenney [off-list ref] Date: Mon Aug 14 08:54:39 2017 -0700 EXP: Trace tick return from tick_nohz_stop_sched_tick Signed-off-by: Paul E. McKenney [off-list ref]diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index c7a899c5ce64..7358a5073dfb 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c@@ -817,6 +817,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, * (not only the tick). */ ts->sleep_length = ktime_sub(dev->next_event, now); + trace_printk("tick_nohz_stop_sched_tick: %lld\n", (tick - ktime_get()) / 1000); return tick; }
Should I be seeing negative values? A small sample:
<idle>-0 [015] d... 1602.039695: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: -1602250019
<idle>-0 [009] d... 1602.039701: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: -1602250025
<idle>-0 [007] d... 1602.039702: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: -1602250025
<idle>-0 [048] d... 1602.039703: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: 9973
<idle>-0 [006] d... 1602.039704: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: -1602250027
<idle>-0 [001] d... 1602.039730: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: -1602250053
<idle>-0 [008] d... 1602.039732: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: -1602250055
<idle>-0 [006] d... 1602.049695: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: -1602260018
<idle>-0 [009] d... 1602.049695: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: -1602260018
<idle>-0 [001] d... 1602.049695: __tick_nohz_idle_enter: tick_nohz_stop_sched_tick: -1602260018
I have a full trace, I'll send it to you off-list.
cheers