> > 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):
I created a 22 second stall, which triggered two self-detected stall
messages. The second one covers 18 seconds (and reports 17444 ms
of system cputime), but still reports the half_timeout of 2.5 s on
the right. The duration since the snapshot was taken would be
more meaningful.
[ 3428.422726] tcrypt: rcu testing - preempt_disable for rude 22 s
[ 3433.419012] rcu: INFO: rcu_preempt self-detected stall on CPU
[ 3433.425145] rcu: 52-....: (4993 ticks this GP) idle=7704/1/0x4000000000000000 softirq=8448/8448 fqs=1247
[ 3433.435073] rcu: hardirqs softirqs csw system cond_resched
[ 3433.443096] rcu: number: 0 5 0 0
[ 3433.450930] rcu: cputime: 8 0 2489 ==> 2500 (ms)
[ 3433.460151] rcu: current: in_kernel_fpu_begin=0 this_cpu_preemptible=0
[ 3433.467006] (t=5044 jiffies g=127261 q=179 ncpus=56)
[ 3433.472285] CPU: 52 PID: 44429 Comm: modprobe Not tainted 6.0.0+ #11
[ 3433.478879] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/08/2022
[ 3433.487664] RIP: 0010:rude_sleep_cycles+0x13/0x27 [tcrypt]
...
[ 3433.717818] </TASK>
[ 3448.719827] rcu: INFO: rcu_preempt self-detected stall on CPU
[ 3448.725816] rcu: 52-....: (19994 ticks this GP) idle=7704/1/0x4000000000000000 softirq=8448/8448 fqs=5002
[ 3448.735736] rcu: hardirqs softirqs csw system cond_resched
[ 3448.743735] rcu: number: 0 38 0 0
[ 3448.751560] rcu: cputime: 354 0 17444 ==> 2500 (ms)
[ 3448.760780] rcu: current: in_kernel_fpu_begin=0 this_cpu_preemptible=0
[ 3448.767643] (t=20348 jiffies g=127261 q=1019 ncpus=56)
[ 3448.773106] CPU: 52 PID: 44429 Comm: modprobe Not tainted 6.0.0+ #11
[ 3448.779704] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/08/2022
[ 3448.788488] RIP: 0010:rude_sleep_cycles+0x13/0x27 [tcrypt]
...