Developer Guide

Developer Guide for Intel® oneAPI Math Kernel Library Linux*

ID 766690
Date 12/16/2022
Public

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Document Table of Contents

Environment Variables

The table below lists Intel® oneAPI Math Kernel Library environment variables to control runs of the Intel Distribution for LINPACK Benchmark.

Environment Variable

Description

Value

HPL_LARGEPAGE

Defines the memory mapping to be used for the Intel® Xeon® processor.

0 or 1:

  • 0 - normal memory mapping, default.

  • 1 - memory mapping with large pages (2 MB per page mapping). It may increase performance.

HPL_LOG

Controls the level of detail for the HPL output.

An integer ranging from 0 to 2:

  • 0 - no log is displayed.

  • 1 - only one root node displays a log, exactly the same as the ASYOUGO option provides.

  • 2 - the most detailed log is displayed. All P root nodes in the processor column that owns the current column block display a log.

HPL_HOST_CORE, HPL_HOST_NODE

Specifies cores or Non-Uniform Memory Access (NUMA) nodes to be used.

HPL_HOST_NODE requires NUMA mode to be enabled. You can check whether it is enabled by the numactl –-hardware command.

The default behavior is auto-detection of the core or NUMA node.

A list of integers ranging from 0 to the largest number of a core or NUMA node in the cluster and separated as explained in example 3.

HPL_SWAPWIDTH

Specifies width for each swap operation.

16 or 24. The default is 24.

You can set Intel Distribution for LINPACK Benchmark environment variables using the PMI_RANK and PMI_SIZE environment variables of the Intel MPI library, and you can create a shell script to automate the process.

Examples of Environment Settings

#

Settings

Behavior of the Intel Distribution for LINPACK Benchmark

1

Nothing specified

All Intel® Xeon® processors in the cluster are used.

2

HPL_MIC_DEVICE=0,2

HPL_HOST_CORE=1-3,8-10

Intel® Xeon® processor cores 1,2,3,8,9, and 10 are used.

3

HPL_HOST_NODE=1

Only Intel® Xeon® processor cores on NUMA node 1 are used.

Product and Performance Information

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

Notice revision #20201201