Hi Max/Jim,
Based on your script, I created the following script to print which pid is
interrupted how many times every 2 second. The result shows pid 0 is
interrupted most: about 50k every 2 second, that's 25k per second. How could
it be interrupted so frequently? For the clock interrupt, it only interrupts
100 times per second, which is much less than 25k per second. Where could it
come from?
The box has lots of network traffic from mysql, I think the network
interrupt will cause the mysqld (pid 10490) to be interrupted instead of pid
0.
#!/usr/sbin/dtrace -s
interrupt-start
{
self->intr = curthread->t_intr;
}
interrupt-start
/self->intr/
{
@inter[self->intr->t_procp->p_pidp->pid_id, cpu] = count();
}
interrupt-complete
/self->intr/
{
self->intr = 0;
}
profile:::tick-2sec
{
printf("report completed at time:%Y\n",walltimestamp);
printf("*******************************************\n");
printa("%d-%d: %...@d\n", @inter);
trunc(@inter,0);
}
0 89152 :tick-2sec report completed at time:2010 Jan
24 02:48:56
*******************************************
0-0: 1
0-2: 1
0-8: 1
0-12: 1
0-14: 1
0-16: 1
0-20: 1
0-21: 1
0-22: 1
1095-7: 4
0-6: 5
0-5: 8
264-7: 8
10490-7: 4962
0-7: 49131
0 89152 :tick-2sec report completed at time:2010
Jan 24 02:48:58
*******************************************
0-0: 1
0-5: 4
1095-7: 4
10490-7: 4200
0-7: 50305
0 89152 :tick-2sec report completed at time:2010
Jan 24 02:49:00
*******************************************
0-3: 4
1095-7: 4
0-5: 8
25388-7: 818
10490-7: 1582
0-7: 51507
On Fri, Jan 22, 2010 at 4:21 PM, m...@bruningsystems.com <
m...@bruningsystems.com> wrote:
> Hi Qihua Wu,
>
> Here is a script that shows process args for process that was interrupted,
> and cpu. It is easily modified
> to add pid.
>
> #!/usr/sbin/dtrace -s
>
> interrupt-start
> {
> self->intr = curthread->t_intr;
> }
>
> interrupt-start
> /self->intr/
> {
> @[stringof(self->intr->t_procp->p_user.u_psargs), cpu] = count();
> }
>
> interrupt-complete
> /self->intr/
> {
> self->intr = 0;
> }
>
>
> max
>
>
> Qihua Wu wrote:
>
>> So do we have a way to know what causes the interrupt (this may be got by
>> intrstat) and which pid/execname is interrupted?
>>
>> Thanks
>> Daniel
>>
>> On Thu, Jan 21, 2010 at 10:43 PM, Jim Mauro <james.ma...@sun.com> wrote:
>>
>>
>>
>>> "sched" is the execname of the PID 0 process (run "ps -e").
>>>
>>> The string "sched" gets plugged into the DTrace execname variable
>>> if the CPU is in an interrupt handler when a probe fires.
>>>
>>> CPU 0 is very likely taking the clock interrupts, which by default
>>> occur every 10 milliseconds.
>>>
>>> HTH,
>>> /jim
>>>
>>>
>>>
>>>
>>> Qihua Wu wrote:
>>>
>>>
>>>
>>>> Why sched is often interrupt on cpu 0 instead of distribution evenly on
>>>> all cpu?
>>>>
>>>> dtrace -n 'sdt:::interrupt-start { @num[execname,cpu] = count(); }'
>>>> dtrace: description 'sdt:::interrupt-start ' matched 1 probe
>>>> ^C
>>>>
>>>> sched 4
>>>> 355
>>>> sched 18
>>>> 358
>>>> sched 8
>>>> 369
>>>> sched 10
>>>> 370
>>>> sched 11
>>>> 370
>>>> sched 12
>>>> 408
>>>> sched 13
>>>> 408
>>>> sched 15
>>>> 408
>>>> sched 19
>>>> 408
>>>> sched 20
>>>> 408
>>>> sched 21
>>>> 408
>>>> sched 22
>>>> 408
>>>> sched 23
>>>> 408
>>>> sched 14
>>>> 409
>>>> sched 9
>>>> 410
>>>> sched 2
>>>> 411
>>>> sched 16
>>>> 411
>>>> sched 6
>>>> 422
>>>> sched 17
>>>> 456
>>>> sched 3
>>>> 469
>>>> sched 5
>>>> 510
>>>> sched 7
>>>> 564
>>>> sched 1
>>>> 3079
>>>> sched 0
>>>> 535071
>>>>
>>>> Thanks,
>>>> Daniel
>>>> ------------------------------------------------------------------------
>>>>
>>>> _______________________________________________
>>>> dtrace-discuss mailing list
>>>> dtrace-discuss@opensolaris.org
>>>>
>>>>
>>>>
>>>>
>>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> dtrace-discuss mailing list
>> dtrace-discuss@opensolaris.org
>>
>
>
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