To provide accurate performance data and enable source analysis, the Intel® VTune™ Amplifier requires debug information for the binary files it analyzes. If it does not find debug information in the binaries, the VTune Amplifier statically identifies function boundaries and assigns hotspot addresses to generated pseudo names func@address for such functions, for example:
If debug information is absent, the Call Stack pane may not unwind the call stack correctly for user-mode sampling and tracing analysis types. Additionally in some cases, it can take significantly more time to finalize the results for modules that do not have debug information.
To enable downloading the debug information for the kernel and system libraries:
Download and install debug info packages available for your system version. The kernel file (for example, vmlinux) must be uncompressed. Linux vendors typically release compressed kernel files stripped of symbols. However, some vendors have released special debug versions of their kernels that are also suitable for performance analysis.
For Red Hat Enterprise* Linux 3, 4 and 5 distros, Red Hat provides "debuginfo" RPMs that can be obtained from http://people.redhat.com/duffy/debuginfo/. After installing the RPM, the debug version of the kernel file is located under /usr/lib/debug/boot (EL 3) or /usr/lib/debug/lib/modules (EL 4, 5).
For SuSE Linux Enterprise* 9, 10, and 11 distros, SuSE provides "debug" kernel RPMs (kernel-debug-*.rpm) available on the install CD or from the website. After installing the RPM, the debug version of the kernel file is located under /boot/vmlinux-*-debug (on IA32 systems with or without Intel Extended Memory 64 Technology) or under /boot/vmlinuz-*-debug (on systems with the Intel Itanium® processor). You need to manually uncompress this kernel file using the gunzip program.
For all others distributions, after configuring the kernel sources:
Edit the kernel source top-level Makefile and add the -g option to the following variables:
CFLAGS_KERNEL := -g
CFLAGS := -g
Run make clean; make to create the vmlinux kernel file with debug information. Once a debug version of the kernel is created or obtained, specify that kernel file as the one to use during performance analysis.
To enable generating the debug information for your binary files:
Compile your code using the -g option that usually produces debugging information in the DWARF format. If DWARF is not a default debugging information format for the compiler, use the -gdwarf-version option, for example: -gdwarf-2 or -gdwarf-3.
Note
VTune Amplifier supports two ways of specifying a separate debug info file for an ELF executable/library binary:
If an executable file in the ELF format contains a build ID and has a separate debug info file with the name generated by the build ID, the VTune Amplifier is able to find and validate the separate symbol file if proper search directories are set. While searching the symbol file, the VTune Amplifier checks the .build-id subdirectory of each search directory for a file named hh/hhhhhhhhhhh.debug where hh is the first 2 hexadecimal characters of build ID and hhhhhhhhhhh is the remaining part.
If an executable file contains a debug link (specified in the .gnu_debuglink section) with a name of separate debug info file, VTune Amplifier tries to find it.
Please refer to the Binutils documentation for more details on how to create separate debug info files and link them with an executable/library via debug link or build ID.