Submitter: Jenkins
Branch:    master

commit 1c04e18ec922b6a6f6de6734fbceb0eed336f2ee
Author: Mikhail Chernik <>
Date:   Mon Jun 27 22:04:46 2016 +0200

    Fix require thread policy for multi-NUMA computes
    CPU thread policy "require" demands that instances are created on hosts
    with hardware threads, e.g HyperThreading. It is possible that a compute
    has several NUMA nodes, but only some of them contribute to the list of
    pinned CPUs. In this case NUMATopologyFiler will exclude the compute
    from candidates even if hardware threads are enabled and cores from
    other NUMA nodes are available for CPU pinning.
    This commit allows a compute with enabled HyperThreading to pass
    NUMATopologyFilter if at least one NUMA node contributes to the list of
    cores allowed for CPU pinning.
    Change-Id: I3235cc6bf1a2a9e29a17acc43472e2a6bd4c26ec
    Closes-Bug: 1596692

** Changed in: nova
       Status: In Progress => Fix Released

You received this bug notification because you are a member of Yahoo!
Engineering Team, which is subscribed to OpenStack Compute (nova).

  NUMATopologyFilter filters out a compute from candidates for booting a
  VM with  'hw:cpu_thread_policy=require' unless cores from all NUMA
  nodes are enabled in vcpu_pin_set on the compute

Status in OpenStack Compute (nova):
  Fix Released

Bug description:
  The 'require' CPU thread policy allows booting instances on hardware
  threads siblings only. However, if a compute host has several NUMA
  nodes and at least one NUMA node does not contribute to a list of
  pinned CPU cores, NUMATopologyFilter excludes such node from possible
  targets to an instance.

  Steps to reproduce:

  1) On a compute with several NUMA nodes vcpu_pin_set key of nova.conf
  does not contain sibling thread cores from one NUMA node (e.g. they
  are allocated for OVS with DPDK support)

  ex: vcpu_pin_set=0,1,20,21

  List of cores on a NUMA node can be obtained with lstopo or numactl -H 
  # numactl -H
  available: 4 nodes (0-3)
  node 0 cpus: 0 1 2 3 4 20 21 22 23 24
  node 0 size: 64328 MB
  node 0 free: 21952 MB
  node 1 cpus: 5 6 7 8 9 25 26 27 28 29
  node 1 size: 64510 MB
  node 1 free: 30091 MB

  Sibling cores can be found with # cat
  /sys/bus/cpu/devices/cpu*/topology/thread_siblings_list command

  # cat /sys/bus/cpu/devices/cpu{0,1}/topology/thread_siblings_list 

  2) Create corresponding flavor

  # openstack flavor create pinned.threads_require --ram 2048 --disk 0 --vcpus 2
  # openstack flavor set pinned.threads_require --property 
"hw:cpu_thread_policy=require" --property "hw:cpu_policy=dedicated"

  3) Boot an instance with created flavor
  # openstack server create --flavor pinned.threads_require --image cirros vm1

  4) List instances:
  # openstack server list

  Expected result: 
  Instance vm1 is booted

  Actiual result:
  Instance vm1 is in ERROR state with message 'No valid host was found. There 
are not enough hosts available.' (assuming there are no other computes with 
sibling thread cores available)

To manage notifications about this bug go to:

Mailing list:
Post to     :
Unsubscribe :
More help   :

Reply via email to