numa_mode(5)numa_mode(5)NAMEnuma_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 Symmet‐
ric 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 par‐
tition 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 exten‐
sively 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 parame‐
ter 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 val‐
ues. For information about the effects of installation on tunable val‐
ues, 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 ALSOmpsched(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)
