Issue while profiling a 32 bit application running on 64 bit OS

Issue while profiling a 32 bit application running on 64 bit OS

asifch's picture

Hi, I am trying to profile a 32 bit application, which is running on a 64 bit RHEL4 on x86_64 (Xeon - Nehalem) using x86_64 vesrion of PTU 3.2 in statistical callgraph mode. I am facing with lot of warning messages, suggesting it is not able to load ibvtssagent.so. The application runs and generates empty profile. Enabling LD_DEBUG=files tells me file=/opt/intel/ptu/lib32/libvtssagent.so [0]; needed by sh [0]ERROR: ld.so: object '/opt/intel/ptu/lib32/libvtssagent.so' from LD_PRELOAD cannot be preloaded: ignored. file=/opt/intel/ptu/lib32/libvtssagent.so [0]; needed by /usr/bin/cpp [0] ERROR: ld.so: object '/opt/intel/ptu/lib32/libvtssagent.so' from LD_PRELOAD cannot be preloaded: ignored. file=/opt/intel/ptu/lib32/libvtssagent.so [0]; needed by /usr/libexec/gcc/x86_64-redhat-linux/3.4.6/cc1 [0] ERROR: ld.so: object '/opt/intel/ptu/lib32/libvtssagent.so' from LD_PRELOAD cannot be preloaded: ignored. This is repeated multiple times. Has anyone seen this king ofbehaviorand aware of any solution/workaround to this problem? Thanks in advance for the help Asif.

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MrAnderson (Intel)'s picture

Hi Asif:

Which release of RHEL4 are you using?

Also, it would appear that you are configuring PTU to launch a script. Does that script set the LD_PRELOAD environment variable? It would appear that it is changing it such that the PTU modules are not loaded into the app's process space.

Have you ever used PTU successfully with this app/script? Or, is this the first time you have tried?

Regards, MrAnderson
asifch's picture

Hi, I am using RHELAS release 4 (Nahant Update 8). Kernel version is2.6.9-89.ELlargesmp My application is doing ld_open on many shared libraries inside the code. I guess PTU modules will be loaded before this happens. I have actually created a micro benchmark that ld_opens a shared library to see if that is causing any trouble. But that got profiled without any trouble. This is the first time I am trying to use PTU with this APP. We have used PTU successfully on several other applications on similar machines though. Thanks, Asif.

Konstantin Lupach (Intel)'s picture

I would try
ldd -r -d /opt/intel/ptu/lib32/libvtssagent.so
Is this small benchmark a 32-bit application?

MrAnderson (Intel)'s picture

Yes, he said it was a 32-bit app in the title. What should he look for in the output of the 'ldd' command you specified?

Regards, MrAnderson
asifch's picture

Yes..It is a 32 bit application. ldd -r -d /opt/intel/ptu/lib32/libvtssagent.so linux-gate.so.1 => (0xffffe000) libpthread.so.0 => /lib/tls/libpthread.so.0 (0xf7df3000) libdl.so.2 => /lib/libdl.so.2 (0xf7def000) libc.so.6 => /lib/tls/libc.so.6 (0xf7cc0000) /lib/ld-linux.so.2 (0x56555000) What information are you looking for here? Thanks, Asif.

Konstantin Lupach (Intel)'s picture

I wanted to make sure that vtssagent does not have unresolved dependencies on this system.
I can not propose anything else.
The question was also sent to this feature developers, however,there is no a high chancethat they will be able to help.

MrAnderson (Intel)'s picture

it would appear that "linux-gate.so.1" is not resolved, from the ldd output. is that file on the system?

Regards, MrAnderson

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