TMI-capable Network Fabrics Control

I_MPI_TMI_LIBRARY

Select the TMI library to be used.

Syntax

I_MPI_TMI_LIBRARY=<library>

Arguments

<library>

Specify a TMI library to be used instead of the default libtmi.so

Description

Set this environment variable to select a specific TMI library. Specify the full path to the TMI library if the library does not locate in the dynamic loader search path.

I_MPI_TMI_PROVIDER

Define the name of the TMI provider to load.

Syntax

I_MPI_TMI_PROVIDER=<name>

Arguments

<name>

The name of the TMI provider to load

Description

Set this environment variable to define the name of the TMI provider to load. The name must also be defined in the tmi.conf configuration file.

I_MPI_TMI_NBITS_RANK

Defines the number of the bits that can be reserved for the storage of MPI rank values at the TMI level.

Syntax

I_MPI_TMI_NBITS_RANK=<num_bits>

Arguments

<num_bits>

The number of the bits reserved for the MPI rank storage

<=32 and > 0

The default value is 24

Description

The value of I_MPI_TMI_NBITS_RANK specifies how many MPI ranks can be referenced and distinguished at TMI level. Thus, if you specify the default value for this environment variable, I_MPI_TMI_NBITS_RANK=24, the number of ranks allowed for running a job is 224=16M ranks.

Note

The value of I_MPI_TMI_NBITS_RANK is related to the MPI_TAG_UB. The larger value you specify for I_MPI_TMI_NBITS_RANK , the less tag value MPI_TAG_UB is supported. The less value you specify for I_MPI_TMI_NBITS_RANK , the larger tag value MPI_TAG_UB is supported. The correct MPI application should always query MPI_TAG_UB for the largest supported tag value.

I_MPI_TMI_DSEND

Control the capability of the direct send in the TMI netmod.

Syntax

I_MPI_TMI_DSEND=<arg>

Arguments

<arg>

Binary indicator

enable | yes | on | 1

Enable the direct send. This is default value

disable | no | off | 0

Disable the direct send

Description

Use the direct send capability to block MPI_Send calls only. Before using the direct send capability, ensure that you use it for single-threaded MPI applications and check if you have selected TMI as the network fabrics (setting I_MPI_FABRICS=tmi).

Note

The direct send capability is only supported in the TMI version 1.1 or higher. If you use a lower TMI version, the specified value of I_MPI_TMI_DSEND is ignored.

I_MPI_TMI_DRECV

Control the capability of the direct receive in the TMI fabric.

Syntax

I_MPI_TMI_DRECV=<arg>

Arguments

<arg>

Binary indicator

enable | yes | on | 1

Enable the direct receive. This is default value

disable | no | off | 0

Disable the direct receive

Description

Use the direct receive capability to block MPI_Recv calls only. Before using the direct receive capability, ensure that you use it for single-threaded MPI applications and check if you have selected TMI as the network fabrics (setting I_MPI_FABRICS=tmi).