LSF Version 7.3 - Administering Platform LSF

Administering Platform LSF 621
Achieving Performance and Scalability
Processor, core, and
thread CPU load
balancing
By default, the number of CPUs on a host represents the number of physical
processors a machine has. For LSF hosts with multiple cores, threads, and
processors,
ncpus can be defined by the cluster administrator to consider one of the
following:
◆ Processors
Processors and cores
Processors, cores, and threads
Globally, this definition is controlled by the parameter
EGO_DEFINE_NCPUS in
lsf.conf or ego.conf. The default behavior for ncpus is to consider only the
number of physical processors (
EGO_DEFINE_NCPUS=procs).
Binding job processes randomly to multiple processors, cores, or threads, may
affect job performance. Processor binding configured with LSF_BIND_JOB in
lsf.conf or BIND_JOB in lsb.applications, detects the
EGO_DEFINE_NCPUS policy to load balance the job processes by processor, core,
or thread (PCT).
For example, if a host's PCT policy is set to processor
(EGO_DEFINE_NCPUS=procs), the first job process is bound to the first physical
processor, the second job process is bound to the second physical processor and so
on.
If host's PCT policy is set to core level (EGO_DEFINE_NCPUS=cores), the first job
process is bound to the first core on the first physical processor, the second job
process is bound to the first core on the second physical processor, the third job
process is bound to the second core on the first physical processor and so on.
If host's PCT policy is set to thread level (EGO_DEFINE_NCPUS=threads), the
first job process is bound to the first thread on the first physical processor, the
second job process is bound to the first thread on the second physical processor, the
third job process is bound to the second thread on the first physical processor and
so on.
Feature
Interactions
◆ Existing CPU affinity features
Processor binding of LSF job processes will not take effect on a master host with
the following parameters configured.
❖ MBD_QUERY_CPUS
❖ LSF_DAEMONS_CPUS
❖ EGO_DAEMONS_CPUS
◆ IRIX cpusets
Processor binding cannot be used with IRIX cpusets. If an execution host is
configured as part of a cpuset, processor binding is disabled on that host.
◆ Job requeue, rerun, and migration
When a job is requeued, rerun or migrated, a new job process is created. If
processor binding is enabled when the job runs, the job processes will be bound
to a processor.
◆ badmin hrestart