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hwloc-bind

NAME

hwloc-bind - Launch a command that is bound to specific processors and/or memory.

SYNOPSIS

hwloc-bind [options] <location1> [<location2> [...] ] [--] <command> ...

OPTIONS

See below for a description of valid <location> formats.

--get

Report the current bindings.

--single

Bind on a single CPU to prevent migration.

--strict

Require strict binding.

--get

Retrieve the current process binding

--pid <pid>

Operate on pid <pid>

-p --physical

take OS/physical indexes instead of logical indexes

-l --logical

take logical indexes instead of physical/OS indexes (default)

-v

Verbose output.

--version

Report version and exit.

DESCRIPTION

hwloc-bind execs an executable (with optional command line arguments) that is bound to the specified location (or list of locations). Upon successful execution, hwloc-bind simply sets bindings and then execs the executable over itself.

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-bind's operation is best described through several examples.

To run the echo command on the first logical processor of the second socket:

    hwloc-bind socket:1.pu:0 -- echo hello

which is exactly equivalent to

    hwloc-bind socket:1.pu:0 echo hello

To bind the "echo" command to the first core of the second socket and the second core of the first socket:

    hwloc-bind socket:1.core:0 socket:0.core:1 echo hello

Note that binding the "echo" command to multiple processors is probably meaningless (because "echo" is likely implemented as a single-threaded application); these examples just serve to show what hwloc-bind can do.

To run on the three first sockets on the second and third nodes:

    hwloc-bind node:1-2.socket:0:3 echo hello

To run on processor with physical index 2 in socket with physical index 1:

    hwloc-bind --physical socket:1.core:2 echo hello

To run on odd cores within even sockets:

    hwloc-bind socket:even.core:odd echo hello

To run on the first socket, except on its second and fifth cores:

    hwloc-bind socket:0 ~socket:0.core:1 ~socket:0.core:4 echo hello

The --get option can report current bindings. This example shows nesting hwloc-bind invocations to set a binding and then report it:

    hwloc-bind node:1.socket:2 hwloc-bind --get

On one of the hwloc developer's machines, this example reports "0x00004444,0x44000000". The mask reported on your machine may be different.

Locations may also be specified as a hex bit mask (typically generated by hwloc-calc). For example:

    hwloc-bind 0x00004444,0x44000000 echo hello
    hwloc-bind `hwloc-calc node:1.socket:2` echo hello

RETURN VALUE

Upon successful execution, hwloc-bind execs the command over itself. The return value is therefore whatever the return value of the command is.

hwloc-bind will return nonzero if any kind of error occurs, such as (but not limited to): failure to parse the command line, failure to retrieve process bindings, or lack of a command to execute.

SEE ALSO

hwloc(7), lstopo(1), hwloc-calc(1), hwloc-distrib(1)