From: Michael Ellerman <mpe@ellerman•id.au>
To: paulmck@linux•vnet.ibm.com,
Jonathan Cameron <Jonathan.Cameron@huawei•com>
Cc: dzickus@redhat•com, sfr@canb•auug.org.au, linuxarm@huawei•com,
Nicholas Piggin <npiggin@gmail•com>,
abdhalee@linux•vnet.ibm.com, tglx@linutronix•de,
sparclinux@vger•kernel.org, akpm@linux-foundation•org,
linuxppc-dev@lists•ozlabs.org, David Miller <davem@davemloft•net>,
linux-arm-kernel@lists•infradead.org
Subject: Re: RCU lockup issues when CONFIG_SOFTLOCKUP_DETECTOR=n - any one else seeing this?
Date: Wed, 16 Aug 2017 22:43:52 +1000 [thread overview]
Message-ID: <87wp63smwn.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20170815154743.GK7017@linux.vnet.ibm.com>
"Paul E. McKenney" <paulmck@linux•vnet.ibm.com> writes:
...
>
> commit 33103e7b1f89ef432dfe3337d2a6932cdf5c1312
> Author: Paul E. McKenney <paulmck@linux•vnet.ibm.com>
> 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 <paulmck@linux•vnet.ibm.com>
>
> 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
next prev parent reply other threads:[~2017-08-16 12:43 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20170725193039.00007c80@huawei.com>
2017-07-25 12:26 ` RCU lockup issues when CONFIG_SOFTLOCKUP_DETECTOR=n - any one else seeing this? Nicholas Piggin
2017-07-25 13:46 ` Paul E. McKenney
2017-07-25 14:42 ` Jonathan Cameron
2017-07-25 15:12 ` Paul E. McKenney
2017-07-25 16:52 ` Jonathan Cameron
2017-07-25 21:10 ` David Miller
2017-07-26 3:55 ` Paul E. McKenney
2017-07-26 4:02 ` David Miller
2017-07-26 4:12 ` Paul E. McKenney
2017-07-26 8:16 ` Jonathan Cameron
2017-07-26 9:32 ` Jonathan Cameron
2017-07-26 12:28 ` Jonathan Cameron
2017-07-26 12:49 ` Jonathan Cameron
2017-07-26 14:14 ` Paul E. McKenney
2017-07-26 14:23 ` Jonathan Cameron
2017-07-26 15:33 ` Jonathan Cameron
2017-07-26 15:49 ` Paul E. McKenney
2017-07-26 16:54 ` David Miller
2017-07-26 17:13 ` Jonathan Cameron
2017-07-27 7:41 ` Jonathan Cameron
2017-07-26 17:50 ` Paul E. McKenney
2017-07-26 22:36 ` Paul E. McKenney
2017-07-26 22:45 ` David Miller
2017-07-26 23:15 ` Paul E. McKenney
2017-07-26 23:22 ` David Miller
2017-07-27 1:42 ` Paul E. McKenney
2017-07-27 4:34 ` Nicholas Piggin
2017-07-27 12:49 ` Paul E. McKenney
2017-07-27 13:49 ` Jonathan Cameron
2017-07-27 16:39 ` Jonathan Cameron
2017-07-27 16:52 ` Paul E. McKenney
2017-07-28 7:44 ` Jonathan Cameron
2017-07-28 12:54 ` Boqun Feng
2017-07-28 13:13 ` Jonathan Cameron
2017-07-28 14:55 ` Paul E. McKenney
2017-07-28 18:41 ` Paul E. McKenney
2017-07-28 19:09 ` Paul E. McKenney
2017-07-30 13:37 ` Boqun Feng
2017-07-30 16:59 ` Paul E. McKenney
2017-07-29 1:20 ` Boqun Feng
2017-07-28 18:42 ` David Miller
2017-07-28 13:08 ` Jonathan Cameron
2017-07-28 13:24 ` Jonathan Cameron
[not found] ` <20170728165529.GF3730@linux.vnet.ibm.com>
2017-07-28 17:27 ` Jonathan Cameron
2017-07-28 19:03 ` Paul E. McKenney
2017-07-31 11:08 ` Jonathan Cameron
2017-07-31 15:04 ` Paul E. McKenney
2017-07-31 15:27 ` Jonathan Cameron
2017-08-01 18:46 ` Paul E. McKenney
2017-08-02 16:25 ` Jonathan Cameron
2017-08-15 15:47 ` Paul E. McKenney
2017-08-16 1:24 ` Jonathan Cameron
2017-08-16 12:43 ` Michael Ellerman [this message]
2017-08-16 12:56 ` Paul E. McKenney
2017-08-16 15:31 ` Nicholas Piggin
2017-08-16 16:27 ` Paul E. McKenney
2017-08-17 13:55 ` Michael Ellerman
2017-08-20 4:45 ` Nicholas Piggin
2017-08-20 5:01 ` David Miller
2017-08-20 5:04 ` Paul E. McKenney
2017-08-20 13:00 ` Nicholas Piggin
2017-08-20 18:35 ` Paul E. McKenney
2017-08-20 21:14 ` Paul E. McKenney
2017-08-21 0:52 ` Nicholas Piggin
2017-08-21 6:06 ` Nicholas Piggin
2017-08-21 10:18 ` Jonathan Cameron
2017-08-21 14:19 ` Nicholas Piggin
2017-08-21 15:02 ` Jonathan Cameron
2017-08-21 20:55 ` David Miller
2017-08-22 7:49 ` Jonathan Cameron
2017-08-22 8:51 ` Abdul Haleem
2017-08-22 15:26 ` Paul E. McKenney
2017-09-06 12:28 ` Paul E. McKenney
2017-08-22 0:38 ` Paul E. McKenney
2017-07-31 11:09 ` Jonathan Cameron
2017-07-31 11:55 ` Jonathan Cameron
2017-08-01 10:53 ` Jonathan Cameron
2017-07-26 16:48 ` David Miller
2017-07-26 3:53 ` Paul E. McKenney
2017-07-26 7:51 ` Jonathan Cameron
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