Long story short, i want my VM have dedicated CPU and it has to be 1-0-1 map. because i am running VoIP application and i need CPU dedicate to guest VM. what i should do?
On Tue, Dec 15, 2015 at 12:34 PM, Arne Wiebalck <arne.wieba...@cern.ch> wrote: > Thanks for clarifying the terminology, Chris, that’s helpful! > > My two points about performance were: > - without overcommit, an instance confined in a NUMA node does not profit > from 1-to-1 pinning (at least from what we saw); > - an instance spanning multiple NUMA nodes needs to be aware of the topology > (and our instances fulfil your condition for this). > > Cheers, > Arne > > >> On 15 Dec 2015, at 18:19, Chris Friesen <chris.frie...@windriver.com> wrote: >> >> If you specify "vcpu_pin_set=2,3,6,7" in /etc/nova/nova.conf then nova will >> limit the VMs to run on that subset of host CPUs. This involves pinning >> from libvirt, but isn't really considered a "dedicated" instance in nova. >> >> By default, instances that can run on all of the allowed host CPUs are >> considered "non-dedicated", "shared", or "floating" because the vCPUs are >> not mapped one-to-one with a single host CPU. For these instances the CPU >> overcommit value determines how many vCPUs can run on a single host CPU. >> >> If an instance specifies a cpu_policy of "dedicated", then each vCPU is >> mapped one-to-one with a single host CPU. This is known as a "pinned" or >> "dedicated" instance. >> >> The performance differences between the two come into play when there is >> contention. By default a non-dedicated vCPU can have 16x overcommit, so >> there can be 16 vCPUs trying to run on a single host CPU. In contrast, a >> dedicated vCPU gets a whole host CPU all to itself. >> >> As for the guest being aware of the underlying NUMA topology, this isn't >> possible when the number of vCPUs in the instance isn't a multiple of the >> number of hyperthreads in a host core. The problem is that qemu doesn't >> have a way to specify cores with varying numbers of threads. >> >> Chris >> >> On 12/15/2015 10:50 AM, Arne Wiebalck wrote: >>> What was configured was pinning to a set and that is reflected, no? Or is >>> that not referred to as “pinning”? >>> Anyway, for performance we didn’t see a difference between 1:1 pinning and >>> confining (?) the vCPUs to a >>> a set as long as the instance is aware of the underlying NUMA topology. >>> >>> Cheers, >>> Arne >>> >>> >>>> On 15 Dec 2015, at 17:11, Chris Friesen <chris.frie...@windriver.com> >>>> wrote: >>>> >>>> Actually no, I don't think that's right. When pinning is enabled each >>>> vCPU will be affined to a single host CPU. What is showing below is what >>>> I would expect if the instance was using non-dedicated CPUs. >>>> >>>> To the original poster, you should be using >>>> >>>> 'hw:cpu_policy': 'dedicated' >>>> >>>> in your flavor extra-specs to enable CPU pinning. And you should enable >>>> the NUMATopologyFilter scheduler filter. >>>> >>>> Chris >>>> >>>> >>>> >>>> On 12/15/2015 09:23 AM, Arne Wiebalck wrote: >>>>> The pinning seems to have done what you asked for, but you probably >>>>> want to confine your vCPUs to NUMA nodes. >>>>> >>>>> Cheers, >>>>> Arne >>>>> >>>>> >>>>>> On 15 Dec 2015, at 16:12, Satish Patel <satish....@gmail.com> wrote: >>>>>> >>>>>> Sorry forgot to reply all :) >>>>>> >>>>>> This is what i am getting >>>>>> >>>>>> [root@compute-1 ~]# virsh vcpupin instance-00000043 >>>>>> VCPU: CPU Affinity >>>>>> ---------------------------------- >>>>>> 0: 2-3,6-7 >>>>>> 1: 2-3,6-7 >>>>>> >>>>>> >>>>>> Following numa info >>>>>> >>>>>> [root@compute-1 ~]# numactl --hardware >>>>>> available: 2 nodes (0-1) >>>>>> node 0 cpus: 0 3 5 6 >>>>>> node 0 size: 2047 MB >>>>>> node 0 free: 270 MB >>>>>> node 1 cpus: 1 2 4 7 >>>>>> node 1 size: 2038 MB >>>>>> node 1 free: 329 MB >>>>>> node distances: >>>>>> node 0 1 >>>>>> 0: 10 20 >>>>>> 1: 20 10 >>>>>> >>>>>> On Tue, Dec 15, 2015 at 8:36 AM, Arne Wiebalck <arne.wieba...@cern.ch> >>>>>> wrote: >>>>>>> The pinning we set up goes indeed into the <cputune> block: >>>>>>> >>>>>>> —> >>>>>>> <vcpu placement='static'>32</vcpu> >>>>>>> <cputune> >>>>>>> <shares>32768</shares> >>>>>>> <vcpupin vcpu='0' cpuset='0-7,16-23'/> >>>>>>> <vcpupin vcpu='1' cpuset='0-7,16-23'/> >>>>>>> … >>>>>>> <— >>>>>>> >>>>>>> What does “virsh vcpupin <domain>” give for your instance? >>>>>>> >>>>>>> Cheers, >>>>>>> Arne >>>>>>> >>>>>>> >>>>>>>> On 15 Dec 2015, at 13:02, Satish Patel <satish....@gmail.com> wrote: >>>>>>>> >>>>>>>> I am running JUNO version with qemu-kvm-ev-2.1.2-23.el7_1.9.1.x86_64 >>>>>>>> on CentOS7.1 >>>>>>>> >>>>>>>> I am trying to configure CPU pinning because my application is cpu >>>>>>>> hungry. this is what i did. >>>>>>>> >>>>>>>> in /etc/nova/nova.conf >>>>>>>> >>>>>>>> vcpu_pin_set=2,3,6,7 >>>>>>>> >>>>>>>> >>>>>>>> I have created aggregated host with pinning=true and created flavor >>>>>>>> with pinning, after that when i start VM on Host following this i can >>>>>>>> see in guest >>>>>>>> >>>>>>>> ... >>>>>>>> ... >>>>>>>> <vcpu placement='static' cpuset='2-3,6-7'>2</vcpu> >>>>>>>> ... >>>>>>>> ... >>>>>>>> >>>>>>>> But i am not seeing any <cputune> info. >>>>>>>> >>>>>>>> Just want to make sure does my pinning working correctly or something >>>>>>>> is wrong. How do i verify my pinning config is correct? >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> Mailing list: >>>>>>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >>>>>>>> Post to : openstack@lists.openstack.org >>>>>>>> Unsubscribe : >>>>>>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >>>>>>> >>>>>>> -- >>>>>>> Arne Wiebalck >>>>>>> CERN IT >>>>>>> >>>>> >>>>> -- >>>>> Arne Wiebalck >>>>> CERN IT >>>>> >>>>> _______________________________________________ >>>>> Mailing list: >>>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >>>>> Post to : openstack@lists.openstack.org >>>>> Unsubscribe : >>>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >>>>> >>>> >>>> >>>> _______________________________________________ >>>> Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >>>> Post to : openstack@lists.openstack.org >>>> Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >>> >>> -- >>> Arne Wiebalck >>> CERN IT >>> >> > > -- > Arne Wiebalck > CERN IT > > _______________________________________________ > Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack > Post to : openstack@lists.openstack.org > Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack _______________________________________________ Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack Post to : openstack@lists.openstack.org Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
