Ubuntu Manpage: hwloc-bind - Launch a command that is bound to specific processors and/or memory, or

NAME

       hwloc-bind  -  Launch  a  command  that  is bound to specific processors and/or memory, or
       consult the binding of an existing program

SYNOPSIS

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

       Note that hwloc(7) provides a detailed explanation  of  the  hwloc  system  and  of  valid
       <location> formats; it should be read before reading this man page.

OPTIONS

--cpubind Use following arguments for CPU binding (default).

--membind Use following arguments for memory binding. If --mempolicy is not also given,
the default policy is bind.

--mempolicy <policy>
Change the memory binding policy. The available policies are default,
firsttouch, bind, interleave and nexttouch. This option is only meaningful when
an actual binding is also given with --membind. If --membind is given without
--mempolicy, the default policy is bind.

--get Report the current bindings. The output is an opaque bitmask that may be
translated into objects with hwloc-calc (see EXAMPLES below).

When a command is given, the binding is displayed before executing the command.
When no command is given, the program exits after displaying the current
binding.

When combined with --membind, report the memory binding instead of CPU binding.

No location may be given since no binding is performed.

--nodeset Report binding as a NUMA memory node set instead of a CPU set if --get was
given. This is useful for manipulating CPU-less NUMA nodes since their cpuset
is empty while their nodeset is correct.

Also parse input bitmasks as nodesets instead of cpusets.

-e --get-last-cpu-location
Report the last processors where the process ran. The output is an opaque
bitmask that may be translated into objects with hwloc-calc (see EXAMPLES
below).

Note that the result may already be outdated when reported since the operating
system may move the process to other processors at any time according to the
binding.

When a command is given, the last processors is displayed before executing the
command. When no command is given, the program exits after displaying the last
processors.

This option cannot be combined with --membind.

No location may be given since no binding is performed.

--single Bind on a single CPU to prevent migration.

--no-smt Only keep a single PU per core before binding.

--strict Require strict binding.

--pid <pid>
Operate on pid <pid>

--tid <tid>
Operate on thread <tid> instead of on an entire process. The feature is only
supported on Linux for thread CPU binding, or for reporting the last processor
where the thread ran if -e was also passed.

-p --physical
Interpret input locations with OS/physical indexes instead of logical indexes.
This option does not apply to the output, see --get above.

-l --logical
Interpret input locations with logical indexes instead of physical/OS indexes
(default). This option does not apply to the output, see --get above.

--taskset Display CPU set strings in the format recognized by the taskset command-line
program instead of hwloc-specific CPU set string format. This option has no
impact on the format of input CPU set strings, both formats are always accepted.

--restrict <cpuset>
Restrict the topology to the given cpuset.

--disallowed
Include objects disallowed by administrative limitations.

--hbm Only take high bandwidth memory nodes (such as Intel Xeon Phi MCDRAM) in account
when looking for NUMA nodes in the input locations.

This option must be combined with NUMA node locations, such as --hbm numa:1 for
binding on the second HBM node. It may also be written as hbm:1.

--no-hbm Ignore high bandwidth memory nodes (such as Intel Xeon Phi MCDRAM) when looking
for NUMA nodes in the input locations.

-f --force
Launch the executable even if binding failed.

-q --quiet
Hide non-fatal error messages. It includes locations pointing to non-existing
objects, as well as failure to bind. This is usually useful in addition to
--force.

-v --verbose
Verbose output.

--version Report version and exit.

-h --help Display help message 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.

       If  multiple  locations are given, they are combined in the sense that the binding will be
       wider. The process will be allowed to run on every location inside the combination.

       The list of input locations may be explicitly ended with "--".

       If binding fails, or if the binding set is empty, and --force was  not  given,  hwloc-bind
       returns with an error instead of launching the executable.

       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.  More details about how
       locations are specified on the hwloc-bind command line are described in hwloc(7).

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

           $ hwloc-bind package:1.pu:0 -- echo hello

       which is exactly equivalent to the following line as long as there is no ambiguity between
       hwloc-bind option names and the executed command name:

           $ hwloc-bind package:1.pu:0 echo hello

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

           $ hwloc-bind package:1.core:0 package:0.core:1 -- echo hello

       To bind on the first PU of all cores of the first package:

           $ hwloc-bind package:0.core:all.pu:0 -- echo hello
           $ hwloc-bind --no-smt package:0 -- echo hello

       To bind memory on the first high-bandwidth memory node:

           $ hwloc-bind --membind hbm:0 -- echo hello
           $ hwloc-bind --membind --hbm numa:0 -- 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 first three packages on the second and third nodes:

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

       which is also equivalent to:

           $ hwloc-bind node:1-2.package:0-2 -- echo hello

       Note that if you attempt to bind to objects that do not exist, hwloc-bind  will  not  warn
       unless -v was specified.

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

           $ hwloc-bind --physical package:1.core:2 -- echo hello

       To run on odd cores within even packages:

           $ hwloc-bind package:even.core:odd -- echo hello

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

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

       To run anywhere except on the first package:

           $ hwloc-bind all ~package:0 -- echo hello

       To run on a core near the network interface named eth0:

           $ hwloc-bind os=eth0 -- echo hello

       To run on a core near the PCI device whose bus ID is 0000:01:02.0:

           $ hwloc-bind pci=0000:01:02.0 -- echo hello

       To bind memory on second memory node and run on first node (when supported by the OS):

           $ hwloc-bind --cpubind node:1 --membind node:0 -- 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.package:2 -- hwloc-bind --get
           0x00004444,0x44000000

       hwloc-calc may convert this output into actual objects, either with  logical  or  physical
       indexes:

           $ hwloc-calc --physical -I pu `hwloc-bind --get`
           26,30,34,38,42,46
           $ hwloc-calc --logical -I pu `hwloc-bind --get` --sep " "
           24 25 26 27 28 29

       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.package:2` -- echo hello

       The current memory binding may also be reported:

           $ hwloc-bind --membind node:1 --mempolicy interleave -- hwloc-bind --get --membind
           0x000000f0 (interleave)

HINT

       If the graphics-enabled lstopo is available, use for instance

           $ hwloc-bind core:2 -- lstopo --pid 0

       to check what the result of your binding command actually  is.   lstopo  will  graphically
       show where it is bound to by hwloc-bind.

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.