LSF Version 7.3 - Platform LSF Configuration Reference

Description
Determines whether the CPU limit is a per-process limit enforced by the OS or whether it is
a per-job limit enforced by LSF:
•
The per-process limit is enforced by the OS when the CPU time of one process of the job
exceeds the CPU limit.
•
The per-job limit is enforced by LSF when the total CPU time of all processes of the job
exceed the CPU limit.
This parameter applies to CPU limits set when a job is submitted with bsub -c, and to CPU
limits set for queues by CPULIMIT in lsb.queues.
•
LSF-enforced per-job limit: When the sum of the CPU time of all processes of a job exceed
the CPU limit, LSF sends a SIGXCPU signal (where supported by the operating system)
from the operating system to all processes belonging to the job, then SIGINT, SIGTERM
and SIGKILL. The interval between signals is 10 seconds by default. The time interval
between SIGXCPU, SIGINT, SIGKILL, SIGTERM can be configured with the parameter
JOB_TERMINATE_INTERVAL in lsb.params.
Restriction:
SIGXCPU is not supported by Windows.
•
OS-enforced per process limit: When one process in the job exceeds the CPU limit, the
limit is enforced by the operating system. For more details, refer to your operating system
documentation for setrlimit().
The setting of LSB_JOB_CPULIMIT has the following effect on how the limit is enforced:
When LSB_JOB_CPULIMIT is
LSF-enforced per-job limit OS-enforced per-process limit
y Enabled Disabled
n Disabled Enabled
Not defined Enabled Enabled
Default
Not defined
Notes
To make LSB_JOB_CPULIMIT take effect, use the command badmin hrestart all to restart
all sbatchds in the cluster.
Changing the default Terminate job control action: You can define a different terminate action
in lsb.queues with the parameter JOB_CONTROLS if you do not want the job to be killed.
For more details on job controls, see Administering Platform LSF.
Limitations
If a job is running and the parameter is changed, LSF is not able to reset the type of limit
enforcement for running jobs.
•
If the parameter is changed from per-process limit enforced by the OS to per-job limit
enforced by LSF (LSB_JOB_CPULIMIT=n changed to LSB_JOB_CPULIMIT=y), both
per-process limit and per-job limit affect the running job. This means that signals may be
lsf.conf
412 Platform LSF Configuration Reference