toolchain/gcc-linaro-6.3.1-2017.02-x8.../share/doc/libgomp.html/Environment-Variables.html

136 lines
8.5 KiB
HTML
Raw Permalink Normal View History

2024-03-22 05:10:17 +00:00
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Copyright (C) 2006-2016 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "Funding Free Software", the Front-Cover
texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below). A copy of the license is included in the section entitled
"GNU Free Documentation License".
(a) The FSF's Front-Cover Text is:
A GNU Manual
(b) The FSF's Back-Cover Text is:
You have freedom to copy and modify this GNU Manual, like GNU
software. Copies published by the Free Software Foundation raise
funds for GNU development. -->
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
<head>
<title>GNU libgomp: Environment Variables</title>
<meta name="description" content="GNU libgomp: Environment Variables">
<meta name="keywords" content="GNU libgomp: Environment Variables">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="Library-Index.html#Library-Index" rel="index" title="Library Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="index.html#Top" rel="up" title="Top">
<link href="OMP_005fCANCELLATION.html#OMP_005fCANCELLATION" rel="next" title="OMP_CANCELLATION">
<link href="omp_005fget_005fwtime.html#omp_005fget_005fwtime" rel="prev" title="omp_get_wtime">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.indentedblock {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
div.smalllisp {margin-left: 3.2em}
kbd {font-style:oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nocodebreak {white-space:nowrap}
span.nolinebreak {white-space:nowrap}
span.roman {font-family:serif; font-weight:normal}
span.sansserif {font-family:sans-serif; font-weight:normal}
ul.no-bullet {list-style: none}
-->
</style>
</head>
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<a name="Environment-Variables"></a>
<div class="header">
<p>
Next: <a href="Enabling-OpenACC.html#Enabling-OpenACC" accesskey="n" rel="next">Enabling OpenACC</a>, Previous: <a href="Runtime-Library-Routines.html#Runtime-Library-Routines" accesskey="p" rel="prev">Runtime Library Routines</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Library-Index.html#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Environment-Variables-1"></a>
<h2 class="chapter">3 Environment Variables</h2>
<p>The environment variables which beginning with <code>OMP_</code> are defined by
section 4 of the OpenMP specification in version 4.5, while those
beginning with <code>GOMP_</code> are GNU extensions.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">&bull; <a href="OMP_005fCANCELLATION.html#OMP_005fCANCELLATION" accesskey="1">OMP_CANCELLATION</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Set whether cancellation is activated
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fDISPLAY_005fENV.html#OMP_005fDISPLAY_005fENV" accesskey="2">OMP_DISPLAY_ENV</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Show OpenMP version and environment variables
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fDEFAULT_005fDEVICE.html#OMP_005fDEFAULT_005fDEVICE" accesskey="3">OMP_DEFAULT_DEVICE</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Set the device used in target regions
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fDYNAMIC.html#OMP_005fDYNAMIC" accesskey="4">OMP_DYNAMIC</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Dynamic adjustment of threads
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fMAX_005fACTIVE_005fLEVELS.html#OMP_005fMAX_005fACTIVE_005fLEVELS" accesskey="5">OMP_MAX_ACTIVE_LEVELS</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Set the maximum number of nested parallel regions
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fMAX_005fTASK_005fPRIORITY.html#OMP_005fMAX_005fTASK_005fPRIORITY" accesskey="6">OMP_MAX_TASK_PRIORITY</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Set the maximum task priority value
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fNESTED.html#OMP_005fNESTED" accesskey="7">OMP_NESTED</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Nested parallel regions
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fNUM_005fTHREADS.html#OMP_005fNUM_005fTHREADS" accesskey="8">OMP_NUM_THREADS</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Specifies the number of threads to use
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fPROC_005fBIND.html#OMP_005fPROC_005fBIND" accesskey="9">OMP_PROC_BIND</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Whether theads may be moved between CPUs
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fPLACES.html#OMP_005fPLACES">OMP_PLACES</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Specifies on which CPUs the theads should be placed
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fSTACKSIZE.html#OMP_005fSTACKSIZE">OMP_STACKSIZE</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Set default thread stack size
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fSCHEDULE.html#OMP_005fSCHEDULE">OMP_SCHEDULE</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How threads are scheduled
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fTHREAD_005fLIMIT.html#OMP_005fTHREAD_005fLIMIT">OMP_THREAD_LIMIT</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Set the maximum number of threads
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="OMP_005fWAIT_005fPOLICY.html#OMP_005fWAIT_005fPOLICY">OMP_WAIT_POLICY</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How waiting threads are handled
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="GOMP_005fCPU_005fAFFINITY.html#GOMP_005fCPU_005fAFFINITY">GOMP_CPU_AFFINITY</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Bind threads to specific CPUs
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="GOMP_005fDEBUG.html#GOMP_005fDEBUG">GOMP_DEBUG</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Enable debugging output
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="GOMP_005fSTACKSIZE.html#GOMP_005fSTACKSIZE">GOMP_STACKSIZE</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Set default thread stack size
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="GOMP_005fSPINCOUNT.html#GOMP_005fSPINCOUNT">GOMP_SPINCOUNT</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Set the busy-wait spin count
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="GOMP_005fRTEMS_005fTHREAD_005fPOOLS.html#GOMP_005fRTEMS_005fTHREAD_005fPOOLS">GOMP_RTEMS_THREAD_POOLS</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Set the RTEMS specific thread pools
</td></tr>
</table>
<hr>
<div class="header">
<p>
Next: <a href="Enabling-OpenACC.html#Enabling-OpenACC" accesskey="n" rel="next">Enabling OpenACC</a>, Previous: <a href="Runtime-Library-Routines.html#Runtime-Library-Routines" accesskey="p" rel="prev">Runtime Library Routines</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Library-Index.html#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
</body>
</html>