** Also affects: libvirt (Ubuntu Focal) Importance: Undecided Status: New
** Also affects: libvirt (Ubuntu Xenial) Importance: Undecided Status: New ** Also affects: libvirt (Ubuntu Bionic) Importance: Undecided Status: New ** Also affects: libvirt (Ubuntu Groovy) Importance: Undecided Status: New ** Changed in: libvirt (Ubuntu) Status: New => Fix Released ** Tags added: server-next -- You received this bug notification because you are a member of नेपाली भाषा समायोजकहरुको समूह, which is subscribed to Xenial. Matching subscriptions: Ubuntu 16.04 Bugs https://bugs.launchpad.net/bugs/1915811 Title: Empty NUMA topology in machines with high number of CPUs Status in libvirt package in Ubuntu: Fix Released Status in libvirt source package in Xenial: New Status in libvirt source package in Bionic: New Status in libvirt source package in Focal: New Status in libvirt source package in Groovy: New Bug description: [impact] libvirt fails to populate its NUMA topology when the machine has a large number of CPUs assigned to a single node. This happens when the number of CPUs fills the bitmask (all to one), hitting a workaround introduced to build the NUMA topology on machines that have non contiguous node ids. This has been already fixed upstream in the commits listed below. [scope] The fix is needed for Xenial, Bionic, Focal and Groovy. It's fixed upstream with commits 24d7d85208 and 551fb778f5 which are included in v6.8, so both are already in hirsute. [test case] On a machine like the EPYC 7702P, after setting the NUMA config to NPS1 (single node per processor), or just a VM with 128 CPUs, "virsh capabilities" does not show the NUMA topology: # virsh capabilities | xmllint --xpath '/capabilities/host/topology' - <topology> <cells num="0"> </cells> </topology> When it should show (edited to shorten the description): <topology> <cells num="1"> <cell id="0"> <memory unit="KiB">5027820</memory> <pages unit="KiB" size="4">1256955</pages> <pages unit="KiB" size="2048">0</pages> <distances> <sibling id="0" value="10"/> </distances> <cpus num="128"> <cpu id="0" socket_id="0" core_id="0" siblings="0"/> .... <cpu id="127" socket_id="127" core_id="0" siblings="127"/> </cpus> </cell> </cells> </topology> [Where problems could occur] Any regression would likely involve a misconstruction of the NUMA topology, in particular for machines with non contiguous node ids. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1915811/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~group.of.nepali.translators Post to : group.of.nepali.translators@lists.launchpad.net Unsubscribe : https://launchpad.net/~group.of.nepali.translators More help : https://help.launchpad.net/ListHelp