numa_mode(5) File Formats Manual numa_mode(5)
NAME
numa_mode - HP-UX kernel mode on NUMA servers
VALUES
Default
Allowed values
Integer values or
DESCRIPTION
HP-UX can operate in one of two modes (LORA or SMP) when operating on ccNUMA (cache coherent Non-Uniform Memory Architecture) servers.
LORA is the Locality-Optimized Resource Alignment mode. SMP is the Symmetric Multiprocessor mode. See for information on LORA mode.
LORA mode is optimal when the underlying partition is configured according to the guidelines for LORA Partitions. In LORA mode, HP-UX
attempts to align the allocation of memory and scheduling of processes within the minimal number of localities. SMP mode is optimal when
the partition does not meet the guidelines for LORA partitions. In SMP mode, HP-UX distributes the memory and CPU allocations across all
the localities.
The tunable allows users to set the mode independent of the partition guidelines.
There are 3 possible values for this tunable.
This value is the default value.
HP-UX evaluates the hardware configuration at boot time to determine the appropriate mode. HP-UX automatically switches into
LORA mode when the partition meets the guidelines for LORA partitions; otherwise, it switches into SMP mode. The tunable
should also be set to zero to allow HP-UX to perform memory allocation in NUMA aware manner when HP-UX is set to LORA mode.
Use to determine the HP-UX mode of operation.
This value causes HP-UX to operate in LORA mode even if the partition does
not meet LORA Partitions guidelines. It minimizes the number of localities used to meet the CPU and memory requirements of a
workload.
This value causes HP-UX to operate in SMP mode operation. It spreads the
load evenly across all the localities.
Restrictions on Changing
Changes to this tunable take effect upon next reboot.
When Should the Value of This Tunable Be Changed to 1?
should be changed to 1 if the partition is configured with more than 50% local memory but is not compliant with LORA guidelines.
When Should the Value of This Tunable Be Changed to -1?
should be set to -1 on NUMA server if the partition has been extensively tuned for NUMA by passing hints to APIs such as and or by using
commands such as The memory allocation policy should be appropriately set using the tunable.
WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its meaning changed in future releases of
HP-UX.
Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parameter values. After installation,
some tunable parameters may no longer be at the default or recommended values. For information about the effects of installation on tun-
able values, consult the documentation for the kernel software being installed. For information about optional kernel software that was
factory installed on your system, see at
AUTHOR
was developed by HP.
SEE ALSO
mpsched(1), parconfig(1M), parcreate(1M), parmodify(1M), fadvise(2), shmget(2), mpctl(2), numa_policy(5), numa_sched_launch(5), lora(7).
white paper at
Tunable Kernel Parameters numa_mode(5)