Specifies the number of tasks of a parallel job you want to run per node. Use this keyword in conjunction with the node keyword. The value you specify on the node keyword can be a range or a single value. If the node keyword is not specified, then the default value is one node.
The maximum number of tasks a job step can request is limited by the total_tasks keyword in the administration file (provided this keyword is specified). That is, the maximum must be less than any total_tasks value specified in a user, group, or class stanza.
The value of the tasks_per_node keyword applies only to the job step in which you specify the keyword. (That is, this keyword is not inherited by other job steps.)
Also, you cannot specify both the tasks_per_node keyword and the total_tasks keyword within a job step.
The syntax is:
tasks_per_node = number
Where number is the number of tasks you want to run per node. The default is one task per node.
For example, to specify a range of seven to 14 nodes, with four tasks running on each node, enter the following:
node = 7,14 tasks_per_node = 4
The above job step runs 28 to 56 tasks, depending on the number of nodes allocated to the job step.