LSF Version 7.3 - Administering Platform LSF

Administering Platform LSF 245
Understanding Resources
In cases where CPU architectures and operating system combinations may not
support accurate processor, core, thread detection, LIM uses the defaults of
1 processor, 1 core per physical processor, and 1 thread per core. If LIM detects that
it is running in a virtual environment (for example, VMware®), each detected
processor is similarly reported (as a single-core, single-threaded, physical
processor).
LIM only detects hardware that is recognized by the operating system. LIM
detection uses processor- or OS-specific techniques (for example, the Intel CPUID
instruction, or Solaris
kstat()/core_id). If the operating system does not
recognize a CPU or core (for example, if an older OS does not recognize a
quad-core processor and instead detects it as dual-core), then LIM will not
recognize it either.
NOTE: RQL normalization never considers threads. Consider a hyper-thread enabled Pentium:
Threads are not full-fledged CPUs, so considering them as CPUs would artificially lower the system
load.
ncpus detection on
AIX
On a machine running AIX, detection of ncpus is different. Under AIX, the
number of detected physical processors is always 1, whereas the number of detected
cores is always the number of cores across all physical processors. Thread detection
is the same as other operating systems (the number of threads per core).
Define ncpus—processors, cores, or threads
A cluster administrator must define how ncpus is computed. Usually, the number
of available job slots is equal to the value of
ncpus; however, slots can be redefined
at the EGO resource group level. The
ncpus definition is globally applied across the
cluster.
1 Open lsf.conf or ego.conf.
◆ UNIX and Linux:
LSF_CONFDIR/lsf.conf
LSF_CONFDIR/ego/cluster_name/kernel/conf/ego.conf
◆ Windows:
LSF_CONFDIR\lsf.conf
LSF_CONFDIR\ego\cluster_name\kernel\conf\ego.conf
IMPORTANT: You can set EGO_DEFINE_NCPUS in ego.conf only if EGO is enabled in the LSF
cluster. If EGO is not enabled, you must set EGO_DEFINE_NCPUS in lsf.conf.
2 Define the parameter EGO_DEFINE_NCPUS=[procs | cores | threads].
Set it to one of the following:
◆ procs (where ncpus=procs)
◆ cores (where ncpus=procs * cores)
◆ threads (where ncpus=procs * cores * threads)