LSF Version 7.3 - Platform LSF Configuration Reference

MEMLIMIT
Syntax
MEMLIMIT=[default_limit] maximum_limit
Description
The per-process (hard) process resident set size limit (in KB) for all of the processes belonging
to a job from this queue (see getrlimit(2)).
Sets the maximum amount of physical memory (resident set size, RSS) that may be allocated
to a process.
By default, if a default memory limit is specified, jobs submitted to the queue without a job-
level memory limit are killed when the default memory limit is reached.
If you specify only one limit, it is the maximum, or hard, memory limit. If you specify two
limits, the first one is the default, or soft, memory limit, and the second one is the maximum
memory limit.
LSF has two methods of enforcing memory usage:
•
OS Memory Limit Enforcement
•
LSF Memory Limit Enforcement
OS memory limit enforcement
OS memory limit enforcement is the default MEMLIMIT behavior and does not require
further configuration. OS enforcement usually allows the process to eventually run to
completion. LSF passes MEMLIMIT to the OS that uses it as a guide for the system scheduler
and memory allocator. The system may allocate more memory to a process if there is a surplus.
When memory is low, the system takes memory from and lowers the scheduling priority (re-
nice) of a process that has exceeded its declared MEMLIMIT. Only available on systems that
support RLIMIT_RSS for setrlimit().
Not supported on:
•
Sun Solaris 2.x
•
Windows
LSF memory limit enforcement
To enable LSF memory limit enforcement, set LSB_MEMLIMIT_ENFORCE in lsf.conf to
y. LSF memory limit enforcement explicitly sends a signal to kill a running process once it has
allocated memory past MEMLIMIT.
You can also enable LSF memory limit enforcement by setting LSB_JOB_MEMLIMIT in
lsf.conf to y. The difference between LSB_JOB_MEMLIMIT set to y and
LSB_MEMLIMIT_ENFORCE set to y is that with LSB_JOB_MEMLIMIT, only the per-job
memory limit enforced by LSF is enabled. The per-process memory limit enforced by the OS
is disabled. With LSB_MEMLIMIT_ENFORCE set to y, both the per-job memory limit
enforced by LSF and the per-process memory limit enforced by the OS are enabled.
Available for all systems on which LSF collects total memory usage.
lsb.queues
Platform LSF Configuration Reference 303