Re: [libvirt] [PATCH v5 1/4] numa: describe siblings distances within cells

From: Wim ten Have <wim.ten.have(a)oracle.com&gt; Add support for describing NUMA distances in a domain's <numa> <cell> XML description. Below is an example of a 4 node setup: <cpu> <numa> <cell id='0' cpus='0-3' memory='2097152' unit='KiB'> <distances> <sibling id='0' value='10'/> <sibling id='1' value='21'/> <sibling id='2' value='31'/> <sibling id='3' value='21'/> </distances> </cell> <cell id='1' cpus='4-7' memory='2097152' unit='KiB'> <distances> <sibling id='0' value='21'/> <sibling id='1' value='10'/> <sibling id='2' value='21'/> <sibling id='3' value='31'/> </distances> </cell> <cell id='2' cpus='8-11' memory='2097152' unit='KiB'> <distances> <sibling id='0' value='31'/> <sibling id='1' value='21'/> <sibling id='2' value='10'/> <sibling id='3' value='21'/> </distances> <cell id='3' cpus='12-15' memory='2097152' unit='KiB'> <distances> <sibling id='0' value='21'/> <sibling id='1' value='31'/> <sibling id='2' value='21'/> <sibling id='3' value='10'/> </distances> </cell> </numa> </cpu> A <cell> defines a NUMA node. <distances> describes the NUMA distance from the <cell> to the other NUMA nodes (the <sibling>s). For example, in above XML description, the distance between NUMA node0 <cell id='0' ...> and NUMA node2 <sibling id='2' ...> is 31. Valid distance value are '10 <= value <= 255'. A distance value of 10 represents the distance to the node itself. A distance value of 20 represents the default value for remote nodes but other values are possible depending on the physical topology of the system. When distances are not fully described, any missing sibling distance values will default to 10 for local nodes and 20 for remote nodes.

Signed-off-by: Wim ten Have <wim.ten.have(a)oracle.com&gt;