flux-hwloc(1)

SYNOPSIS

flux hwloc info [OPTIONS]

flux hwloc topology [OPTIONS]

DESCRIPTION

The flux-hwloc utility queries hwloc(7) topology information for an instance by gathering XML from the core resource module.

COMMANDS

flux hwloc requires a COMMAND argument. The supported commands are

info [-l,--local|-r,--rank=NODESET]
Dump a short-form summary of the total number of Machines, Cores, and Processing Units (PUs) available across all flux-brokers in the current instance. With --ranks, dump information for only the specified ranks. With --local dump local system information.
topology [-l,--local|-r,--rank=NODESET]
Dump current aggregate topology XML for the current session to stdout. With --rank only dump aggregate topology for specified ranks. With --local dump topology XML for the local system. With hwloc < 2.0, this command will dump a custom topology with multiple machines when the aggregate contains multiple ranks. This is not possible with hwloc 2.0 because multiple Machine objects in a topology is no longer supported, and therefore the XML for each rank will be printed separately.

NODESET FORMAT

A NODESET is a comma separated list of integer ranks. Ranks may be listed individually or as a range in the form l-k where l < k.

Some examples of nodesets.

``1''
rank 1
``0-3''
ranks 0, 1, 2, and 3 listed in a range
``0,1,2,3''
ranks 0, 1, 2, and 3 listed individually
``2,5''
ranks 2 and 5
``2,4-5''
ranks 2, 4, and 5

As a special case, the string ``all'' can be specified to indicate every rank available in the flux instance.

EXAMPLES

When using HWLOC < 2.0 only, the output of flux hwloc topology may be piped to other hwloc(7) commands such as lstopo(1) or hwloc-info(1), e.g.

$ flux hwloc topology | lstopo-no-graphics --if xml -i -
System (31GB total)
  Machine L#0 (7976MB) + Package L#0
    Core L#0 + PU L#0 (P#0)
    Core L#1 + PU L#1 (P#1)
    Core L#2 + PU L#2 (P#2)
    Core L#3 + PU L#3 (P#3)
  Machine L#1 (7976MB) + Package L#1
    Core L#4 + PU L#4 (P#0)
    Core L#5 + PU L#5 (P#1)
    Core L#6 + PU L#6 (P#2)
    Core L#7 + PU L#7 (P#3)
  Machine L#2 (7976MB) + Package L#2
    Core L#8 + PU L#8 (P#0)
    Core L#9 + PU L#9 (P#1)
    Core L#10 + PU L#10 (P#2)
    Core L#11 + PU L#11 (P#3)
  Machine L#3 (7976MB) + Package L#3
    Core L#12 + PU L#12 (P#0)
    Core L#13 + PU L#13 (P#1)
    Core L#14 + PU L#14 (P#2)
    Core L#15 + PU L#15 (P#3)

SEE ALSO

lstopo(1), hwloc: https://www.open-mpi.org/projects/hwloc/