3.0 KiB
Configuring CPU Core Assignments Using CLI
You can improve the performance and capacity of specific functions by assigning more CPU cores using the following command:
[sysadmin@controller-0 ~(keystone_admin)]$ system host-cpu-modify [--nowrap] -f <function> [-c <cpulist>] [-p0 <num_cores_on_processor0>] [-p1 <num_cores_on_processor1>] [-p2 <num_cores_on_processor2>] [-p3 <num_cores_on_processor3>] <hostnameorid>
function
Use this command with the -f
argument, which specifies
the function, such as platform and
application-isolated whose core count is to be
modified.
Note
Any core that is not specified as one of these functions will be considered as an application core.
- Platform
-
You can reserve one or more cores per node for platform use. One core on each host is required to run the operating system and associated services. For a combined controller and worker node in a or configuration, two cores are required.
The ability to assign platform cores to specific nodes offers increased flexibility for high-performance configurations. For example, you can dedicate certain nodes for platform use such that other nodes that service requests are available for the containers (hosted applications) that require high-performance servicing.
Note
If you plan on running the -openstack application on an or deployment, at least 4 platform cores are required for adequate Horizon Web Interface and CLI performance and 6 platform cores are recommended.
- Application-isolated
-
You can isolate a core from the host process scheduler by specifying the application-isolated function. This minimizes interruptions by other tasks to ensure more predictable latency.
Note
The tasks on the isolated cores will not be automatically load-balanced by the Linux task scheduler. Thus, it is up to the application to affine tasks appropriately.
cpulist
Use this option with the -c
argument. This option
specifies an explicit list of CPUs.
Note
Only one CPU function can be specified with the -c
option. The c
option must be used in the final call to
system host-cpu-modify
. Unlike specifying by core
counts, when using the -c
option, sysinv will not
automatically add in any unspecified hyperthreads if the host has
hyperthreading enabled. It is up to the caller to ensure that all
sibling threads are included in the CPU list.
num_cores_on_processor
Use this option with the -pX
argument where
X
represents the NUMA node whose count you want to modify.
Multiple unique -pX
arguments may be specified, with a core
count for each NUMA node.
hostnameorid
This is the name or ID of a host.