CentOS - Aug 2010 - Is oprofile still working?

Hi all,

Is anyone using oprofile?

I'm getting segfaults from opreport at the moment, and I'm not sure if 
it is opreport, or just me.

In case it is something just plain daft I am doing, here is how it goes:

 opcontrol --reset
 opcontrol --setup --no-vmlinux
 opcontrol --start

... now I run my program, /tmp/myprog ...

 opcontrol --dump
 opcontrol --shutdown

then I run,
 opreport -l /tmp/myprog
and get:
 warning: [vdso] (tgid:4780 range:0x8d7000-0x8d8000) could not be found.
 warning: [vdso] (tgid:4784 range:0x860000-0x861000) could not be found.
 CPU: Core Solo / Duo, speed 1067 MHz (estimated)
 Counted CPU_CLK_UNHALTED events (Unhalted clock cycles) with a unit 
mask of 0x00 (Unhalted core cycles) count 100000
 Segmentation fault

The problem seems to come when I ask for symbols (-l).
I can't seem to get much information out of other running programs either.
I'm running the opcontrol commands as root, and I've tried opreport as 
root or myself.

I'm sure I have done this successfully in the past (but this is the 
first time I have tried it in a while).
I have what should be a fully patched CentOS 5.5 here.
I see this: https://bugzilla.redhat.com/show_bug.cgi?id=529028 , but it 
looks to be too old to be relevant (I notice I have the updated binutils 
that the final link in the bugreport points to).
I've tried this on two different machines, but they are similar 
configurations I guess in that they are both 32bit intel machines.

Hywel.

On Thursday 12 August 2010, Hywel Richards wrote:
> Hi all,
>
> Is anyone using oprofile?
>
> I'm getting segfaults from opreport at the moment, and I'm not sure
if
> it is opreport, or just me.
I've tried the steps you outline below and it works for me (updated C5.5 as
of
10m ago). My only guess is that your binary is b0rked. What happens if you 
do "opreport -l" instead of "opreport -l /tmp/myprog"? Was
myprog compiled
with "-g"?

And just to be sure, could you provide "uname -a" and "rpm -q
oprofile".

/Peter
> In case it is something just plain daft I am doing, here is how it goes:
>
>  opcontrol --reset
>  opcontrol --setup --no-vmlinux
>  opcontrol --start
>
> ... now I run my program, /tmp/myprog ...
>
>  opcontrol --dump
>  opcontrol --shutdown
>
> then I run,
>  opreport -l /tmp/myprog
> and get:
>  warning: [vdso] (tgid:4780 range:0x8d7000-0x8d8000) could not be found.
>  warning: [vdso] (tgid:4784 range:0x860000-0x861000) could not be found.
>  CPU: Core Solo / Duo, speed 1067 MHz (estimated)
>  Counted CPU_CLK_UNHALTED events (Unhalted clock cycles) with a unit
> mask of 0x00 (Unhalted core cycles) count 100000
>  Segmentation fault
...
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Peter Kjellstrom wrote:
> On Thursday 12 August 2010, Hywel Richards wrote:
>   
>> Hi all,
>>
>> Is anyone using oprofile?
>>
>> I'm getting segfaults from opreport at the moment, and I'm not
sure if
>> it is opreport, or just me.
>>     
>
> I've tried the steps you outline below and it works for me (updated
C5.5 as of
> 10m ago). My only guess is that your binary is b0rked. What happens if you 
> do "opreport -l" instead of "opreport -l /tmp/myprog"?
Was myprog compiled
> with "-g"?
>
> And just to be sure, could you provide "uname -a" and "rpm
-q oprofile".
>
> /Peter
>   
"opreport -l" gives:

warning: /no-vmlinux could not be found.
warning: [vdso] (tgid:11369 range:0xdc9000-0xdca000) could not be found.
warning: [vdso] (tgid:2453 range:0x154000-0x155000) could not be found.
warning: [vdso] (tgid:24792 range:0x8e6000-0x8e7000) could not be found.
warning: [vdso] (tgid:24797 range:0xd4a000-0xd4b000) could not be found.
warning: [vdso] (tgid:3211 range:0x660000-0x661000) could not be found.
warning: [vdso] (tgid:3426 range:0xed7000-0xed8000) could not be found.
warning: [vdso] (tgid:3429 range:0x798000-0x799000) could not be found.
warning: [vdso] (tgid:3549 range:0x3a8000-0x3a9000) could not be found.
warning: [vdso] (tgid:3551 range:0x86b000-0x86c000) could not be found.
warning: [vdso] (tgid:3575 range:0x90a000-0x90b000) could not be found.
warning: [vdso] (tgid:3595 range:0xd9d000-0xd9e000) could not be found.
warning: [vdso] (tgid:3641 range:0xfed000-0xfee000) could not be found.
warning: [vdso] (tgid:3672 range:0xd1e000-0xd1f000) could not be found.
warning: [vdso] (tgid:3673 range:0x133000-0x134000) could not be found.
warning: [vdso] (tgid:3684 range:0x5c2000-0x5c3000) could not be found.
warning: [vdso] (tgid:3693 range:0x189000-0x18a000) could not be found.
warning: [vdso] (tgid:3698 range:0x903000-0x904000) could not be found.
warning: [vdso] (tgid:3702 range:0x139000-0x13a000) could not be found.
warning: [vdso] (tgid:3709 range:0xeb1000-0xeb2000) could not be found.
warning: [vdso] (tgid:3756 range:0xf03000-0xf04000) could not be found.
warning: [vdso] (tgid:3788 range:0xb7f49000-0xb7f4a000) could not be found.
warning: [vdso] (tgid:3800 range:0x7e4000-0x7e5000) could not be found.
warning: [vdso] (tgid:3836 range:0x662000-0x663000) could not be found.
warning: [vdso] (tgid:3899 range:0xd2e000-0xd2f000) could not be found.
warning: [vdso] (tgid:3902 range:0x33c000-0x33d000) could not be found.
warning: [vdso] (tgid:5178 range:0xb7f50000-0xb7f51000) could not be found.
warning: [vdso] (tgid:6643 range:0xfaa000-0xfab000) could not be found.
CPU: Core Solo / Duo, speed 800 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Unhalted clock cycles) with a unit mask 
of 0x00 (Unhalted core cycles) count 100000
bfd_get_section_contents:get_debug:: Bad value


myprog was not compiled with -g, but that shouldn't be a requirement, right?
Anyway, I recompiled my program with -g and I still get a segfault from 
"opreport -l".
If I skip the "-l", it at least doesn't segfault, but then not so 
interesting information:

opreport /tmp/myprog2
CPU: Core Solo / Duo, speed 1867 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Unhalted clock cycles) with a unit mask 
of 0x00 (Unhalted core cycles) count 100000
CPU_CLK_UNHALT...|
  samples|      %|
------------------
    25950 100.000 myprog2

Here's what I get when I do it on, say, gcc (no segfault this time, but 
perhaps it gives some indication of what is going wrong?):

opreport /usr/bin/g++ -l
warning: [vdso] (tgid:25547 range:0xc49000-0xc4a000) could not be found.
warning: [vdso] (tgid:25550 range:0x749000-0x74a000) could not be found.
warning: [vdso] (tgid:25565 range:0xefc000-0xefd000) could not be found.
CPU: Core Solo / Duo, speed 1867 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Unhalted clock cycles) with a unit mask 
of 0x00 (Unhalted core cycles) count 100000
bfd_get_section_contents:get_debug:: Bad value

"uname -a" gives:

Linux myhost 2.6.18-194.11.1.el5 #1 SMP Tue Aug 10 19:09:06 EDT 2010 
i686 i686 i386 GNU/Linux

"rpm -q oprofile" gives:

oprofile-0.9.4-15.el5

I also did an "rpm -V oprofile" - no problems.

For the moment I'm working around this by compiling my program into a 
shared library, and using LD_PROFILE and sprof, which is working well.

Hywel.