HP XC System 3.x Software manual Using the GNU Parallel Make Capability, $ srun -n4 hostname n46

Determine the address of your monitor's display server, as shown at the beginning of "Running an X Terminal Session from a Remote Node" . You can start an X terminal session using this address information in a bsub command with the appropriate options. For example:

$ bsub -n4 -Ip srun -n1 xterm -display 14.26.206.134:0.0

Job <159> is submitted to default queue <normal>. <<Waiting for dispatch ...>>

<<Starting on lsfhost.localdomain>>

The options used in this command are:

-n4	allocate 4 cores
-Ip	interact with the X terminal session
srun -n1	run the job on 1 core
xterm	the job is an X terminal session
-display <address>	monitor's display server address

A remote X terminal session appears on your monitor. The X terminal session job is launched from node n47, which is the LSF execution host node. You can view this job using LSF-HPC and SLURM commands. For example:

$ sinfo
PARTITION AVAIL TIMELIMIT NODES					STATE NODELIST
lsf	up	infinite		2	alloc n[46,48]
$ squeue
JOBID	PARTITION		NAME	USER	ST	TIME	NODES NODELIST
117	lsf		hptclsf@	username R		0:25	2	n[46,48]
$ bjobs
JOBID	USER	STAT QUEUE		FROM_HOST EXEC_HOST JOB_NAME					SUBMIT_TIME
119	lsfadmi RUN		norma	n48	4*n47		*8.136:0.0 date and time

You can now run some jobs from the X terminal session that you started and make use of the full allocation within the LSF-HPC node allocation. For example:

$ srun -n4 hostname n46

n48

n46

n48

$ srun -n2 hostname n46

n48

Exiting from the X terminal session ends the LSF-HPC job.

Using the GNU Parallel Make Capability

By default, the make command invokes the GNU make program. GNU make has the ability to make independent targets concurrently. For example, if building a program requires compiling 10 source files, and the compilations can be done independently, make can manage multiple compilations at once — the number of jobs is user selectable. More precisely, each target's rules are run normally (sequentially within the rule). Typically the rules for an object file target is a single compilation line, so it is common to talk about concurrent compilations, though GNU make is more general.

On non-cluster platforms or command nodes, matching concurrency to the number of cores often works well. It also often works well to specify a few more jobs than cores so that one job can proceed while another is waiting for I/O. On an HP XC system, there is the potential to use compute nodes to do compilations, and there are a variety of ways to make this happen.

One way is to prefix the actual compilation line in the rule with an srun command. So, instead of executing

ccfoo.c -o foo.o it would execute srun cc foo.c -o foo.o. With concurrency, multiple command nodes would have multiple srun commands instead of multiple cc commands. For projects that recursively run make on subdirectories, the recursive make can be run on the compute nodes. For example:

$ cd subdir; srun $(MAKE)...

Using the GNU Parallel Make Capability 93