Re: why could cause PerfTop get nothing output ?

[Luming Yu]

On Thu, Oct 21, 2010 at 10:52 PM, Arnaldo Carvalho de Melo
<acme@xxxxxxxxxxxxxxxxxx> wrote:
> Em Sat, Oct 09, 2010 at 05:07:42AM -0400, Luming Yu escreveu:
>> Hi acme,
>>
>> I got nothing output as below, wondering if it was due to too few interrupts ?
>
> Try using a higher frequency:

Thanks for the hint.

>
> perf top -F 100000

still nothing..

-------------------------------------------------------------------------------
   PerfTop:       0 irqs/sec  kernel:-nan%  exact: -nan% [100000Hz
cycles],  (all, 2 CPUs)
-------------------------------------------------------------------------------

             samples  pcnt  DSO
             _______ _____


>> Is it possbile to get perf top based on samples from other Perf events?
>
> Yes, any event, just specify it like:
>
> perf top -e instructions

still nothing...

# perf top -e instructions

-------------------------------------------------------------------------------
   PerfTop:       0 irqs/sec  kernel:-nan%  exact: -nan% [1000Hz
instructions],  (all, 2 CPUs)
-------------------------------------------------------------------------------

             samples  pcnt  DSO
             _______ _____


>
> - Arnaldo
>
>> [root@localhost clocksource0]# rpm -qa | grep perf
>> perf-2.6.36-0.35.rc7.git0.fc15.x86_64
>> [root@localhost clocksource0]# uname -a
>> Linux localhost.localdomain 2.6.36-0.35.rc7.git0.fc15.x86_64 #1 SMP
>> Wed Oct 6 22:02:54 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux
>> [root@localhost clocksource0]# perf top
>>
>> -------------------------------------------------------------------------------
>> Â ÂPerfTop: Â Â Â 0 irqs/sec Âkernel:-nan% Âexact: -nan% [1000Hz
>> cycles], Â(all, 2 CPUs)
>> -------------------------------------------------------------------------------
>>
>> Â Â Â Â Â Â Âsamples Âpcnt ÂDSO
>> Â Â Â Â Â Â Â_______ _____
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/