[ovirt-users] Network performance drop when compared to other hypervisor with vhost_net on for UDP

[mad Engineer]

I am running RHEL6.5 as Host and Guest on HP server.
Server has 128G and 48 Core[with HT enabled.]

3 VMs are running 2 pinned to first 24 PCPU with proper NUMA pinning,

Guests:

VM1:
6 VCPU  pinned to 6 PCPU NUMA node 1,with 16G RAM

VM2:
6 VCPU pinned to 6 PCPU on NUMA node 0,with 16G RAM

VM3:
2 VCPU ,no pinning,4G RAM

HOST
host has 10 free CPU+24 HT threads which is not allocated and is available.
Host also runs a small application that is single threaded,that uses ~4G RAM.

Total resource to host is 10 CPU+24 HT=34 and 92G unallocated RAM[VMS
dont even use 70% of allocated RAM] also ksm is not running.

Networking:
Uses linux bridge connected to 1Gbps eth0,with ip assigned on eth0
[This IP is called for accessing application running on host]
All vms use virtio and VHOST is on .

Traffic on virtual machines are ~3MBps and combined traffic on host is ~14MBps

"VHOST-pid-of-qemu-process" sometimes uses ~35% CPU.


There is no packet loss,drop or latency,but the issue is with the same
setup on Vmware with same sizing of virtual machines,with the only
difference as application running on host has moved to fourth VM.So in
Vmware there are 4 VMs.
Application gives better number ie on KVM that number is 310 and on
vmware it is 570.Application uses UDP to communicate.

I tried removing VHOST,still value is same.(I hope VHOST-NET UDP issue
is solved)

Thanks for any help