User Guide

Contents

io
Command Line Analysis

This is a PREVIEW FEATURE on Windows* OS. A preview feature may or may not appear in a future production release. It is available for your use in the hopes that you will provide feedback on its usefulness and help determine its future. Data collected with a preview feature is not guaranteed to be backward compatible with future releases. Please send your feedback to parallel.studio.support@intel.com or to intelsystemstudio@intel.com.
This collection type uses the hardware event-based sampling collection and system-wide Ftrace* collection (for Linux* and Android* targets)/ETW collection (Windows* targets) to provide a consistent view of the storage sub-system combined with hardware events and an easy-to-use method to match user-level source code with I/O packets executed by the hardware.
The analysis actively relies on the data produced by the kernel block driver system. In case your platform utilizes a non-standard block driver sub-system (for example, user-space storage drivers), IO metrics will not be available in the analysis type.
Use the Input and Output analysis to identify:
  • Imbalance between I/O and compute operations (HPC applications)
  • Long latency of I/O requests (transactional workloads)
  • Hardware utilization (streaming)
  • Data plane utilization (applications supporting DPDK framework). You can analyze how your application utilizes NIC ports, bandwidth, PCIe, and UPI.
  • I/O performance issues that may be caused by ineffective accesses to remote sockets or under-utilized throughput of an SPDK device

Syntax

vtune
-collect io [-knob <
knobName
=
knobValue
>] [--
target
] [
target_options
]
Knobs:
kernel-stack
,
collect-memory-bandwidth
,
dram-bandwidth-limits
; Linux only:
dpdk
,
spdk
.
Prerequisites:
  • Run the
    VTune
    Profiler
    command line interface with administrative privileges (Windows*) or root privileges (Linux*).
  • Enable system-wide profiling:
    • For system analysis WITH a target application or process specify your application or process and enable system-wide analysis with the
      -analyze-system
      option.
    • For system analysis WITHOUT a target application or process specify the collection duration with the
      -duration
      option.
Examples
Example 1: Disk Input and Output Analysis with a Target Application
This example shows how to run the Disk Input and Output analysis with specified Linux target application and enabled system-wide profiling:
vtune
-collect io -knob kernel-stack=true -analyze-system -- /home/test/myApplication
Example 2: SPDK Input and Output Analysis without a Target Application
This example shows how to run a system-wide SPDK Input and Output analysis without specified target application for 30 seconds:
vtune
-collect io -knob kernel-stack=false -knob spdk=true --duration 30

What's Next

When the data collection is complete, do one of the following to view the result:

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804