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From: "Elliott, Robert (Servers)" <elliott@hpe.com>
To: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>,
	"paulmck@kernel.org" <paulmck@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>,
	Neeraj Upadhyay <quic_neeraju@quicinc.com>,
	Josh Triplett <josh@joshtriplett.org>,
	"Steven Rostedt" <rostedt@goodmis.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	"rcu@vger.kernel.org" <rcu@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v4 4/4] rcu: Add RCU stall diagnosis information
Date: Mon, 7 Nov 2022 20:38:01 +0000	[thread overview]
Message-ID: <MW5PR84MB18427CB2FF17CE0D91BE9944AB3C9@MW5PR84MB1842.NAMPRD84.PROD.OUTLOOK.COM> (raw)
In-Reply-To: <5133bd4b-c17f-f5ed-eae2-fe2d199dc5db@huawei.com>



> > Maybe this shouldn't be a table? Make it grep-friendly:
> > [ 1816.719922] rcu: half-timeout counts: hardirq =5 softirq=10 csw=0
> > [ 1816.725643] rcu: half_timeout cputimes (ms): time=1500 hardirq=3
> softirq=0 system=1492
> 
> I prefer the table. Table look clearer and easier to compare.

Here's an example where it also triggers expedited stalls. The 
self-detected stall prints including the new table can end up
interleaved with the expedited stall prints.

(the table is expanded a bit here to experiment with adding more info, 
and I included the \t prefixes)

[  933.728032] tcrypt: rcu testing - kernel_fpu_disable for rude 6 s
[  938.038278] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 46-.... } 4 jiffies s: 521 root: 0x8/.
[  938.049151] rcu: blocking rcu_node structures (internal RCU debug): l=1:42-55:0x10/.
[  938.057236] Sending NMI from CPU 35 to CPUs 46:
[  938.062048] NMI backtrace for cpu 46
[  938.062050] CPU: 46 PID: 44184 Comm: modprobe Not tainted 6.0.0+ #11
[  938.062052] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/08/2022
[  938.062053] RIP: 0010:rude_sleep_cycles+0x13/0x27 [tcrypt]
...
[  938.062151]  </TASK>
[  938.073277] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 46-.... } 289 jiffies s: 521 root: 0x8/.
[  938.334292] rcu: blocking rcu_node structures (internal RCU debug): l=1:42-55:0x10/.
[  938.342289] Sending NMI from CPU 35 to CPUs 46:
[  938.347049] NMI backtrace for cpu 46
[  938.347050] CPU: 46 PID: 44184 Comm: modprobe Not tainted 6.0.0+ #11
[  938.347051] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/08/2022
[  938.347052] RIP: 0010:rude_sleep_cycles+0x13/0x27 [tcrypt]
...
[  938.347121]  </TASK>
[  938.358275] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 46-.... } 573 jiffies s: 521 root: 0x8/.
[  938.619182] rcu: blocking rcu_node structures (internal RCU debug): l=1:42-55:0x10/.
[  938.627179] Sending NMI from CPU 35 to CPUs 46:
[  938.631939] NMI backtrace for cpu 46
[  938.631939] CPU: 46 PID: 44184 Comm: modprobe Not tainted 6.0.0+ #11
[  938.631941] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/08/2022
[  938.631942] RIP: 0010:rude_sleep_cycles+0x13/0x27 [tcrypt]
...
[  938.631997]  </TASK>
[  938.643272] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: {
[  938.734267] rcu: INFO: rcu_preempt self-detected stall on CPU
[  938.740111]  46-....
[  938.747282] rcu:     46-....: (4948 ticks this GP) idle=a9cc/1/0x4000000000000000 softirq=7598/7598 fqs=1253
[  938.747285] rcu:               hardirqs   softirqs          csw     system cond_resched
[  938.747286] rcu:      number:        0          0            0                      0
[  938.754461]  } 720 jiffies s: 521 root: 0x8/.
[  938.757178] rcu:     cputime:       62          0                     2436              ==> 2500 (ms)
[  938.757179] rcu:     current: in_kernel_fpu_begin=1 this_cpu_preemptible=0
[  938.757181]  (t=5023 jiffies g=61053 q=704 ncpus=56)
[  938.759640] rcu: blocking rcu_node structures (internal RCU debug):

The first "46-" line is from the expedited stall.
The second "46-" line is from the self-detected stall.
The table lines are from the self-detected stall.
The "} 720" line is from the expedited stall.
The "(t=5023" line is from the self-detected stall.
The "blocking" line is from the expedited stall.

[  938.761745] CPU: 46 PID: 44184 Comm: modprobe Not tainted 6.0.0+ #11
[  938.761747] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/08/2022
[  938.982118] RIP: 0010:rude_sleep_cycles+0x13/0x27 [tcrypt]
...
[  939.221833]  </TASK>
[  939.224239]  l=1:42-55:0x10/.
[  939.227440] Sending NMI from CPU 35 to CPUs 46:
[  939.232204] NMI backtrace for cpu 46
[  939.232205] CPU: 46 PID: 44184 Comm: modprobe Not tainted 6.0.0+ #11
[  939.232206] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/08/2022
[  939.232207] RIP: 0010:rude_sleep_cycles+0x13/0x27 [tcrypt]
...
[  939.232262]  </TASK>
[  939.243264] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 46-.... } 1458 jiffies s: 521 root: 0x8/.
[  939.503926] rcu: blocking rcu_node structures (internal RCU debug): l=1:42-55:0x10/.
[  939.511920] Sending NMI from CPU 35 to CPUs 46:
[  939.516678] NMI backtrace for cpu 46
[  939.516679] CPU: 46 PID: 44184 Comm: modprobe Not tainted 6.0.0+ #11
[  939.516680] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/08/2022
[  939.516680] RIP: 0010:rude_sleep_cycles+0x13/0x27 [tcrypt]
...
[  939.516732]  </TASK>
[  939.528263] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: {
[  939.748586] initcall tcrypt_mod_init+0x0/0x1000 [tcrypt] returned -11 after 6020623 usecs
[  939.753200]  46-.... } 1718 jiffies s: 521 root: 0x8/.
[  939.791580] rcu: blocking rcu_node structures (internal RCU debug):



  reply	other threads:[~2022-11-07 20:38 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-04  2:12 [PATCH v4 0/4] " Zhen Lei
2022-11-04  2:12 ` [PATCH v4 1/4] genirq: Fix the return type of kstat_cpu_irqs_sum() Zhen Lei
2022-11-04  2:12 ` [PATCH v4 2/4] sched: Add helper kstat_cpu_softirqs_sum() Zhen Lei
2022-11-04  2:12 ` [PATCH v4 3/4] sched: Add helper nr_context_switches_cpu() Zhen Lei
2022-11-04  2:12 ` [PATCH v4 4/4] rcu: Add RCU stall diagnosis information Zhen Lei
2022-11-04  3:12   ` Leizhen (ThunderTown)
2022-11-04 13:43     ` Paul E. McKenney
2022-11-05  1:58   ` Elliott, Robert (Servers)
2022-11-05  7:03     ` Leizhen (ThunderTown)
2022-11-05 20:32       ` Paul E. McKenney
2022-11-07  3:20         ` Leizhen (ThunderTown)
2022-11-05 20:06     ` Paul E. McKenney
2022-11-07  2:10       ` Elliott, Robert (Servers)
2022-11-07 11:49         ` Leizhen (ThunderTown)
2022-11-07 20:38           ` Elliott, Robert (Servers) [this message]
2022-11-07 21:57             ` Elliott, Robert (Servers)
2022-11-08  3:06               ` Leizhen (ThunderTown)
2022-11-08  5:53                 ` Elliott, Robert (Servers)
2022-11-08  6:41                   ` Leizhen (ThunderTown)
2022-11-08 19:29                     ` Elliott, Robert (Servers)
2022-11-08  3:18             ` Leizhen (ThunderTown)

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