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HWLOC-DISTRIB

HWLOC-DISTRIB

Section: hwloc (1) Updated: Jul 20, 2010
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NAME

hwloc-distrib - Build a number of cpu masks distributed on the system  

SYNOPSIS

topodistrib [options] <integer>  

OPTIONS

--single
Singlify each output to a single CPU.
-v
Verbose messages.
--xml <path>
Read topology from XML file <path> (instead of discovering the topology on the local machine). If <path> is "-", the standard input is used. XML support must have been compiled in to hwloc for this option to be usable.
--synthetic <specification>
Simulate a fake hierarchy (instead of discovering the topology on the local machine). If <specification> is "node:2 pu:3", the topology will contain two NUMA nodes with 3 processing units in each of them.
--version
Report version and exit.
 

DESCRIPTION

hwloc-distrib generates a series of CPU masks in an attempt to distribute a set of processes around multiple processors in a single server. These masks can be used with hwloc-bind(1).

NOTE: It is highly recommended that you read the hwloc(7) overview page before reading this man page. Most of the concepts described in hwloc(7) directly apply to the hwloc-bind utility.  

EXAMPLES

hwloc-distrib's operation is best described through several examples.

If 4 processes have to be distributed across a machine, their CPU masks may be obtained with:


    $ hwloc-distrib 4
    0x0000000f
    0x00000f00
    0x000000f0
    0x0000f000

To get a single processor of each CPU masks (prevent migration in case of binding)


    $ hwloc-distrib 4 --single
    0x00000001
    0x00000100
    0x00000010
    0x00001000

Each output line may be converted independently with hwloc-calc and xargs:


    $ hwloc-distrib 4 --single | xargs -n 1 hwloc-calc --objects
    PU:0
    PU:1
    PU:2
    PU:3

To convert the output into a list of processors that may be passed to dplace -c inside a mpirun command line:


    $ hwloc-distrib 4 --single | xargs hwloc-calc --pulist
    0,8,4,16  

RETURN VALUE

Upon successful execution, hwloc-distrib displays one or more CPU mask strings. The return value is 0.

hwloc-distrib will return nonzero if any kind of error occurs, such as (but not limited to) failure to parse the command line.  

SEE ALSO

hwloc(7)


 

Index

NAME
SYNOPSIS
OPTIONS
DESCRIPTION
EXAMPLES
RETURN VALUE
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 21:13:56 GMT, April 16, 2011