23.9. NUMA Node Tuning

After NUMA node tuning is done using virsh edit, the following domain XML parameters are affected:

<domain>
  ...
  <numatune>
    <memory mode="strict" nodeset="1-4,^3"/>
  </numatune>
  ...
</domain>

<domain>
  ...
  <numatune>
    <memory mode="strict" nodeset="1-4,^3"/>
  </numatune>
  ...
</domain>

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Figure 23.11. NUMA node tuning

Although all are optional, the components of this section of the domain XML are as follows:

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Table 23.6. NUMA node tuning elements
Element	Description
`<numatune>`	Provides details of how to tune the performance of a NUMA host physical machine by controlling NUMA policy for domain processes.
`<memory>`	Specifies how to allocate memory for the domain processes on a NUMA host physical machine. It contains several optional attributes. The `mode` attribute can be set to `interleave`, `strict`, or `preferred`. If no value is given it defaults to `strict`. The `nodeset` attribute specifies the NUMA nodes, using the same syntax as the `cpuset` attribute of the `<vcpu>` element. Attribute `placement` can be used to indicate the memory placement mode for the domain process. Its value can be either `static` or `auto`. If the `<nodeset>` attribute is specified it defaults to the `<placement>` of `<vcpu>`, or `static`. `auto` indicates the domain process will only allocate memory from the advisory nodeset returned from querying numad and the value of the `nodeset` attribute will be ignored if it is specified. If the `<placement>` attribute in `vcpu` is set to `auto`, and the `<numatune>` attribute is not specified, a default `<numatune>` with `<placement>` `auto` and `strict` mode will be added implicitly.