lot of sututtering when exist soft load on host, I tried change vcore threads priority to -20/-10,pinning, no pinning.. the only think works is cpu isolation but its not cool as when i'm shutting down the VM i want this cores availables for other applications(like ffmpeg video encoding on the night) 

 

i'm trying to play with chrt to change the scheduler priority without sucess

root@Tower:~# pidof qemu-system-x86_64
15635
root@Tower:~# chrt -f -p 1 15635
chrt: failed to set pid 15635's policy: Operation not permitted

any idea, suggestion?

 

ryzen 3900x

MSI tomahawk x570 wifi

64gb ram ddr4 3200 cl16

 

I readed a lot and played diferent things and unraid versions and always the same

currently running 6.9.0 beta29 with cpu pinning

passing thourgh onboard audio device, usb controller and a nvidia RTX 2070

 

qemu command

LC_ALL=C \
PATH=/bin:/sbin:/usr/bin:/usr/sbin \
HOME=/var/lib/libvirt/qemu/domain-1-IsaacGaming \
XDG_DATA_HOME=/var/lib/libvirt/qemu/domain-1-IsaacGaming/.local/share \
XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain-1-IsaacGaming/.cache \
XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain-1-IsaacGaming/.config \
QEMU_AUDIO_DRV=none \
/usr/local/sbin/qemu \
-name guest=IsaacGaming,debug-threads=on \
-S \
-object secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-1-IsaacGaming/master-key.aes \
-blockdev '{"driver":"file","filename":"/usr/share/qemu/ovmf-x64/OVMF_CODE-pure-efi.fd","node-name":"libvirt-pflash0-storage","auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-pflash0-format","read-only":true,"driver":"raw","file":"libvirt-pflash0-storage"}' \
-blockdev '{"driver":"file","filename":"/etc/libvirt/qemu/nvram/9239375a-31b7-de02-9205-3209712e6715_VARS-pure-efi.fd","node-name":"libvirt-pflash1-storage","auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-pflash1-format","read-only":false,"driver":"raw","file":"libvirt-pflash1-storage"}' \
-machine pc-i440fx-5.1,accel=kvm,usb=off,vmport=off,dump-guest-core=off,mem-merge=off,kernel_irqchip=on,pflash0=libvirt-pflash0-format,pflash1=libvirt-pflash1-format \
-cpu host,migratable=on,hypervisor=on,topoext=on,svm=on,invtsc=on,kvmclock=off,hv-time,hv-relaxed,hv-vapic,hv-spinlocks=0x1fff,hv-vpindex,hv-vendor-id=1234567890ab,hv-frequencies,kvm=off,host-cache-info=on,l3-cache=off \
-m 16384 \
-overcommit mem-lock=off \
-smp 1,maxcpus=16,sockets=1,dies=1,cores=8,threads=2 \
-object iothread,id=iothread1 \
-object iothread,id=iothread2 \
-uuid ed8709ad-6ea8-ca1c-a980-2cf05d72f688 \
-display none \
-no-user-config \
-nodefaults \
-chardev socket,id=charmonitor,fd=30,server,nowait \
-mon chardev=charmonitor,id=monitor,mode=control \
-rtc base=localtime,driftfix=slew \
-global kvm-pit.lost_tick_policy=delay \
-no-hpet \
-no-shutdown \
-boot strict=on \
-device pci-bridge,chassis_nr=1,id=pci.1,bus=pci.0,addr=0x4 \
-device pci-bridge,chassis_nr=2,id=pci.2,bus=pci.0,addr=0x5 \
-device pci-bridge,chassis_nr=3,id=pci.3,bus=pci.0,addr=0x8 \
-device pci-bridge,chassis_nr=4,id=pci.4,bus=pci.0,addr=0x9 \
-device pci-bridge,chassis_nr=5,id=pci.5,bus=pci.0,addr=0xa \
-device pci-bridge,chassis_nr=6,id=pci.6,bus=pci.0,addr=0xb \
-device pci-bridge,chassis_nr=7,id=pci.7,bus=pci.0,addr=0xc \
-device pci-bridge,chassis_nr=8,id=pci.8,bus=pci.0,addr=0xd \
-device pci-bridge,chassis_nr=9,id=pci.9,bus=pci.0,addr=0xe \
-device pci-bridge,chassis_nr=10,id=pci.10,bus=pci.0,addr=0xf \
-device pci-bridge,chassis_nr=11,id=pci.11,bus=pci.0,addr=0x10 \
-device pci-bridge,chassis_nr=12,id=pci.12,bus=pci.0,addr=0x11 \
-device pci-bridge,chassis_nr=13,id=pci.13,bus=pci.0,addr=0x12 \
-device pci-bridge,chassis_nr=14,id=pci.14,bus=pci.0,addr=0x13 \
-device pci-bridge,chassis_nr=15,id=pci.15,bus=pci.0,addr=0x14 \
-device pci-bridge,chassis_nr=16,id=pci.16,bus=pci.0,addr=0x15 \
-device pci-bridge,chassis_nr=17,id=pci.17,bus=pci.0,addr=0x16 \
-device pci-bridge,chassis_nr=18,id=pci.18,bus=pci.0,addr=0x17 \
-device pci-bridge,chassis_nr=19,id=pci.19,bus=pci.0,addr=0x18 \
-device pci-bridge,chassis_nr=20,id=pci.20,bus=pci.0,addr=0x19 \
-device pci-bridge,chassis_nr=21,id=pci.21,bus=pci.0,addr=0x1a \
-device pci-bridge,chassis_nr=22,id=pci.22,bus=pci.0,addr=0x1b \
-device pci-bridge,chassis_nr=23,id=pci.23,bus=pci.0,addr=0x1c \
-device pci-bridge,chassis_nr=24,id=pci.24,bus=pci.0,addr=0x1d \
-device pci-bridge,chassis_nr=25,id=pci.25,bus=pci.0,addr=0x1e \
-device pci-bridge,chassis_nr=26,id=pci.26,bus=pci.0,addr=0x1f \
-device pci-bridge,chassis_nr=27,id=pci.27,bus=pci.1,addr=0x2 \
-device pci-bridge,chassis_nr=28,id=pci.28,bus=pci.1,addr=0x3 \
-device pci-bridge,chassis_nr=29,id=pci.29,bus=pci.1,addr=0x4 \
-device pci-bridge,chassis_nr=30,id=pci.30,bus=pci.1,addr=0x5 \
-device pci-bridge,chassis_nr=31,id=pci.31,bus=pci.1,addr=0x6 \
-device pci-bridge,chassis_nr=32,id=pci.32,bus=pci.1,addr=0x7 \
-device pci-bridge,chassis_nr=33,id=pci.33,bus=pci.1,addr=0x8 \
-device pci-bridge,chassis_nr=34,id=pci.34,bus=pci.1,addr=0x9 \
-device pci-bridge,chassis_nr=35,id=pci.35,bus=pci.1,addr=0xa \
-device qemu-xhci,p2=15,p3=15,id=usb,bus=pci.0,addr=0x7 \
-device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x3 \
-netdev tap,fd=32,id=hostnet0 \
-device virtio-net,netdev=hostnet0,id=net0,mac=52:54:00:e4:b2:06,bus=pci.1,addr=0x15 \
-netdev tap,fd=33,id=hostnet1 \
-device virtio-net,netdev=hostnet1,id=net1,mac=52:54:00:d0:c9:ca,bus=pci.1,addr=0x14 \
-chardev pty,id=charserial0 \
-device isa-serial,chardev=charserial0,id=serial0 \
-chardev socket,id=charchannel0,fd=34,server,nowait \
-device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0 \
-device 'vfio-pci,host=0000:2d:00.0,id=hostdev0,bus=pci.0,multifunction=on,addr=0x6,romfile=/mnt/user/appdata/TU106 kvm.rom' \
-device vfio-pci,host=0000:2d:00.1,id=hostdev1,bus=pci.0,addr=0x6.0x1 \
-device vfio-pci,host=0000:2d:00.2,id=hostdev2,bus=pci.0,addr=0x6.0x2 \
-device vfio-pci,host=0000:2d:00.3,id=hostdev3,bus=pci.0,addr=0x6.0x3 \
-device vfio-pci,host=0000:01:00.0,id=hostdev4,bootindex=2,bus=pci.2,addr=0x1 \
-device vfio-pci,host=0000:23:00.0,id=hostdev5,bootindex=1,bus=pci.35,addr=0x1 \
-device vfio-pci,host=0000:2f:00.3,id=hostdev6,bus=pci.1,multifunction=on,addr=0x10 \
-device vfio-pci,host=0000:2f:00.4,id=hostdev7,bus=pci.1,addr=0x10.0x1 \
-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
-msg timestamp=on

 

 

 

 

Edited September 30, 20205 yr by segator

I partially fixed it  adding this on the virsh file <vcpusched vcpus='0-11' scheduler='fifo' priority='99'/>

now i can run high load on host that the VM is not affected 200 points drop on cinebench r20 in VM when running full cpu stress test on host

 

but now i notice I have the sttuters only when high network usage, if for example I run iperf3 between host and guest I got 1.27gbps when I should got 10gbps and the VM is completely unusable meanwhile the test is running

 

I tried to isolate the networks, first one for internet conneciton and second one for guest-host only network(NFS, smb.. )

Any idea how to fix the stutters?

    <interface type='bridge'>
      <mac address='52:54:00:e4:b2:06'/>
      <source bridge='br0'/>
      <model type='virtio-net'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x15' function='0x0'/>
    </interface>
    <interface type='bridge'>
      <mac address='52:54:00:d0:c9:ca'/>
      <source bridge='virbr0'/>
      <model type='virtio-net'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x14' function='0x0'/>
    </interface>

 

 

On 10/2/2020 at 8:00 PM, segator said:

but now i notice I have the sttuters only when high network usage, if for example I run iperf3 between host and guest I got 1.27gbps when I should got 10gbps and the VM is completely unusable meanwhile the test is running

 

 

 

 

I have this exact same issue, any luck with fixing this?

Edited October 10, 20205 yr by jongyrocka

nope, I still have same issue

but the machine is more or less usable if there are not extreme load on the virtual ethernet device.