valgrind-users

[Valgrind-users] Beginner hg question: mapping address to the variable

[Raghu R. <rag...@no...>]

This is a newbie question, so please bear with me.  J

 

The environment is the following:

Running on an Intel Westmere processor

Red Hat Enterprise Linux Server release 6.4 (Santiago)

Linux fe5 2.6.32-279.32.1.el6.x86_64 #1 SMP Wed Jun 19 05:25:09 EDT 2013
x86_64 x86_64 x86_64 GNU/Linux

Ifort Version 12.0.4

 

Upon running the application I am seeing some messages such as:

 

==20741== ----------------------------------------------------------------

==20741==

==20741== Possible data race during read of size 4 at 0x420A080 by thread #3

==20741== Locks held: none

==20741==    at 0x40B55AD: __kmp_wait_sleep (in
/apps/intel/composerxe-2011.4.191/composerxe-2011.4.191/compiler/lib/intel64
/libiomp5.so)

==20741==    by 0x40B09AF: __kmp_fork_barrier(int, int) (in
/apps/intel/composerxe-2011.4.191/composerxe-2011.4.191/compiler/lib/intel64
/libiomp5.so)

==20741==    by 0x40B0028: __kmp_launch_thread (in
/apps/intel/composerxe-2011.4.191/composerxe-2011.4.191/compiler/lib/intel64
/libiomp5.so)

==20741==    by 0x40D2638: ??? (in
/apps/intel/composerxe-2011.4.191/composerxe-2011.4.191/compiler/lib/intel64
/libiomp5.so)

==20741==    by 0x4C2D0D4: mythread_wrapper (hg_intercepts.c:219)

==20741==    by 0x7E74850: start_thread (in /lib64/libpthread-2.12.so)

==20741==    by 0xF64F6FF: ???

==20741==

==20741== This conflicts with a previous write of size 4 by thread #2

==20741== Locks held: none

==20741==    at 0x40D337B: ??? (in
/apps/intel/composerxe-2011.4.191/composerxe-2011.4.191/compiler/lib/intel64
/libiomp5.so)

==20741==    by 0x4C2D0D4: mythread_wrapper (hg_intercepts.c:219)

==20741==    by 0x7E74850: start_thread (in /lib64/libpthread-2.12.so)

==20741==    by 0x7BE16FF: ???

==20741==

 

My question is, how do I find the variable located at the address 0x420A080?
The code was ready compiled with -g option, so I was wondering why it was
unable to point me to the variable.  What can I do to get the actual
variable name or the location where if this is happening?

 

Thanks,

 

--Raghu

 

 

Re: [Valgrind-users] Beginner hg question: mapping address to the variable

[David F. <fa...@kd...>]

On Friday 17 January 2014 12:36:32 Raghu Reddy wrote:
> My question is, how do I find the variable located at the address 0x420A080?
> The code was ready compiled with -g option, so I was wondering why it was
> unable to point me to the variable.  What can I do to get the actual
> variable name or the location where if this is happening?

Are you sure that libiomp5.so itself is compiled with -g, not just your 
application?

If yes, maybe try without optimizations (-O0 or nothing instead of -O2), in 
case inlining got in the way. But this looks more to me like a missing -g in 
the first place.

-- 
David Faure, fa...@kd..., http://www.davidfaure.fr
Working on KDE, in particular KDE Frameworks 5

Re: [Valgrind-users] Beginner hg question: mapping address to the variable

[Philippe W. <phi...@sk...>]

On Sat, 2014-01-18 at 10:11 +0100, David Faure wrote:
> On Friday 17 January 2014 12:36:32 Raghu Reddy wrote:
> > My question is, how do I find the variable located at the address 0x420A080?
> > The code was ready compiled with -g option, so I was wondering why it was
> > unable to point me to the variable.  What can I do to get the actual
> > variable name or the location where if this is happening?
> 
> Are you sure that libiomp5.so itself is compiled with -g, not just your 
> application?
> 
> If yes, maybe try without optimizations (-O0 or nothing instead of -O2), in 
> case inlining got in the way. But this looks more to me like a missing -g in 
> the first place.
> 
I agree with DAvid that it looks like libiomp5 looks compiled without
-g, so having this lib compiled with debug is the first thing to do.

Additionally, you might try the option  --read-var-info=yes.


Philippe

Re: [Valgrind-users] Beginner hg question: mapping address to the variable

[Josef W. <Jos...@gm...>]

Am 19.01.2014 15:34, schrieb Philippe Waroquiers:
> On Sat, 2014-01-18 at 10:11 +0100, David Faure wrote:
>> On Friday 17 January 2014 12:36:32 Raghu Reddy wrote:
>>> My question is, how do I find the variable located at the address 0x420A080?
>>> The code was ready compiled with -g option, so I was wondering why it was
>>> unable to point me to the variable.  What can I do to get the actual
>>> variable name or the location where if this is happening?
>>
>> Are you sure that libiomp5.so itself is compiled with -g, not just your 
>> application?

I assume this will get tricky with the OpenMP runtime shipped with the
Intel compiler. Better use GCC to check for races in your code.
And if you know your code is race-free, you make use ICC again.

Josef



>>
>> If yes, maybe try without optimizations (-O0 or nothing instead of -O2), in 
>> case inlining got in the way. But this looks more to me like a missing -g in 
>> the first place.
>>
> I agree with DAvid that it looks like libiomp5 looks compiled without
> -g, so having this lib compiled with debug is the first thing to do.
> 
> Additionally, you might try the option  --read-var-info=yes.
> 
> 
> Philippe
> 
> 
> 
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