Troubleshooting VTune(TM) Amplifier XE's Power Analysis

We have recently learned about various problems users are experiencing when attempting to use the power analysis capability of the VTune™ Amplifier XE 2013.  For example, you may see one of the following messages:

  • Error: Power Analysis is not supported on this platform.
  • Unknown symbol "cpufreq_freq_attr_scaling_available_freqs" in /var/log after building and attempting to load the power driver module

Below are some suggestions for troubleshooting problems with the power analysis feature.

  1. Ensure that your system meets all requirements:
    (much of the following information is available after installation in a readme file located by default at /opt/intel/vtune_amplifier_xe/powerdk/src/README.txt)
    1. Is the processor supported?  Intel® Xeon® processors based on Intel® microarchitecture code named Nehalem or above are required to collect power analysis information.  Note that this does not include the Intel® Core™2, Core™2 Duo and Core™2 Quad processors. To determine which microarchitecture your processor is based on, see About Intel® Processor Numbers.
    2. Is the kernel version supported?  The power driver requires a kernel version of 2.6.32 or higher in order to function and will not build successfully if the kernel version is older.
    3. Is the kernel configured correctly for the power driver? In addition to a kernel version of 2.6.32 or later, the kernel must be configured with the following options enabled:

          CONFIG_MODULES=y
          CONFIG_MODULE_UNLOAD=y
          CONFIG_TRACEPOINTS=y
          CONFIG_FRAME_POINTER=y
          CONFIG_COMPAT=y
          CONFIG_TIMER_STATS=y


      These options can be verified by checking the kernel config file (e.g., /boot/config, /proc/config.gz, /usr/src/linux/.config, etc.).

  2. Ensure that the CPU frequency control module is loaded. Do this by executing the command: '/sbin/lsmod | grep cpufreq' (you will need to be root, of course.)  You should see something like this:

    # lsmod | grep cpufreq
    acpi_cpufreq           18803  1

    Note: there may be other lines output, which are related to the acpi_cpufreq module; however, only acpi_cpufreq must be present.

    If the module is not loaded check to see if the module is compiled. You can find the info in the kernel config file in the /boot directory.
    $> cat /boot/config-2.6.41.1-1.fc15.i686.PAE | grep CPUFREQ
    CONFIG_X86_ACPI_CPUFREQ=m
    1. If the output is 'm', you should be able to find the module in /lib/modules/`uname -r`/kernel/drivers/cpufreq. Load the module using the 'insmod' command.
    2. If the output is 'y', the module is statically compiled. You do not need to take any action.
    3. If it is 'n', you should recompile the kernel with the option enabled and load it using insmod.

  3. Ensure that the power driver module is loaded.  As root, execute 'lsmod | grep apwr'.  You should see something like this:
    # lsmod | grep apwr
    apwr3_1                  61557    0


    If no output is displayed, the driver is not loaded and you should attempt to load it.  As root, change directory to <installation-dir>/powerdk/src and execute the insmod-apwr passing the group name of the group that should own the driver with the -g option, e.g., ./insmod-apwr -g mygroup.  This group should already exist and the users that will collect power data must be members of that group in order to access the driver.  (This is a security measure, allowing you to limit access to this kernel module.)

  4. Ensure that you have access permissions to the power collector device files.  Execute 'ls -l /dev/awpr*'.  You should see something like this:
    # ls -l /dev/apwr*
    crw-rw---- 1 root vtune 242, 0 Feb  4 07:47 /dev/apwr_driver_char_dev


    where 'vtune' is the default group or the one you specified during installation.  Users that want to collect power data must belong to this group.

    If the driver file has 'root' group ownership, you will need to unload (see rmmod-apwr script in <installation-dir>/powerdk/src directory) and reload (see insmod-apwr script) specifying the correct group with the -g option, e.g. ./insmod-apwr -g vtune.  Note: you must be root to execute these scripts.

  5. If, after verifying all of the above, you are still experiencing problems, please collect the following info and submit a support request at Intel® Premier Support and we will be glad to assist you.
    1. execute 'amplxe-runss -context-value-list', redirecting output to a file, e.g. amplxe-runss -context-value-list > valuelist.txt
    2. capture the processor info by executing 'cat /proc/cpuinfo' and redirecting output to a file, e.g., cat /proc/cpuinfo > cpuinfo.txt
    3. create a bug report file using amplxe-feedback, e.g., amplxe-feedback -create-bug-report report.zip

      Please attach all of the above files to your support request when submitting it (see the Attach File link on the support submission form).

Note: executing any of the VTune Amplifier XE commands requires that you first source the amplxe-vars.sh file in the installation directory, e.g., source /opt/intel/amplxe-vars.sh

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