Intel® VTune™ Profiler User Guide

User Guide

Contents

Import Linux Perf* Trace with
VTune
Profiler
 Metrics

If you have your own performance monitoring system based on Linux Perf (for example, as part of your date center infrastructure) and cannot collect data with the
Intel® VTune™
Profiler
, you can still use the
VTune
Profiler
 for data analysis as follows:
  1. Select a
    VTune
    Profiler
     analysis type that is of interest to you.
  2. Use
    VTune
    Profiler
     to get a set of Linux Perf options and apply them to a Perf collection on your target system.
  3. Import the generated Linux Perf trace into a
    VTune
    Profiler
     project and start analysis.

Select a
VTune
Profiler
 Analysis Type

VTune
Profiler
 provides a rich set of predefined analysis types targeting particular performance problems. Each analysis type contains a selected list of low-level performance events and high-level metrics based on them. For example, Microarchitecture Exploration analysis collects all required PMU (Performance Monitoring Unit) events from CPU cores needed for TMA methodology. The Memory Access analysis has a set of both core and uncore PMU events needed for memory-related performance metrics (like DRAM bandwidth).
Using a native Linux Perf interface to collect all needed low-level PMU events may be complicated, so consider reusing the
VTune
Profiler
 configuration targeted for Perf collection (driverless mode).

Run
VTune
Profiler
 to Get Linux Perf Options for Analysis

When the
VTune
Profiler
 runs a performance data collection in the driverless mode, it uses a Linux Perf command line and logs it inside the result folder in the
<
result-folder
>/data.0/perfcmd
 file. To get a correct set of Perf options, do the following:
  1. Install the
    VTune
    Profiler
     on any Linux system with a similar hardware configuration (the same CPU family) as the system where real performance profiling is planned to be run.
  2. Run a
    VTune
    Profiler
     analysis of your interest to generate
    perfcmd
     file with Perf options:
    $
    vtune
    -cl -r <
    result-folder
    > -collect <
    analysis-type
    > -finalization-mode=none -d 1
    For example, for the Microarchitecture Exploration run: 
    vtune-cl -r bogus_result -collect uarch-exploration -finalization-mode=none -d 1
    The
    <
    result-folder
    >/data.0/perfcmd
     file with all necessary Linux Perf options is generated.
    • You do not run any real workload here. The only purpose of this run is to generate the
      perfcmd
       file.
    • VTune
      Profiler
       license is not required for this step since you only collect data without opening it.
  3. Open the
    perfcmd
     file and copy-paste its content to a Linux Perf command invocation on your real target system.
    Your Perf tool should contain a patch from https://github.com/torvalds/linux/commit/f92da71280fb8da3a7c489e08a096f0b8715f939#diff-809984534aa420619413fdf4c260605d. In Linux kernel version >= 4.19, this patch is applied out of the box, in earlier versions you need to manually apply it and recompile the Perf tool.
  4. Run the Linux Perf configuration on your target system.

Import the Linux Perf Trace into a
VTune
Profiler
 Project

  1. Create a
    VTune
    Profiler
     project or open an existing one.
  2. Click the
    Import Result
     toolbar button.
    The
    Import File and Create a Result
     window opens.
  3. Select
    Import a single file
     option and navigate to the Linux Perf trace file.
    VTune
    Profiler
     imports the trace and opens the result in the default viewpoint. You may switch between viewpoints to apply the most relevant. For example, use the Microarchitecture Exploration viewpoint for the Microarchitecture Exploration analysis.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.