[Bug 1794285] Re: 100% Host CPU usage while guest idling

2021-01-11 Thread Launchpad Bug Tracker
[Expired for QEMU because there has been no activity for 60 days.]

** Changed in: qemu
   Status: Incomplete => Expired

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https://bugs.launchpad.net/bugs/1794285

Title:
  100% Host CPU usage while guest idling

Status in QEMU:
  Expired

Bug description:
  Hi,

  We have an appliance that runs a FreeBSD guest on a Yocto-based host via 
qemu-system-x86_64.
  Everything functions fine however the host uses n00% of the CPU (where n = 
#smp) and RAM allocated to it whilst the 1 guest is sat nearing idle.

  Host:
  PID USER  PR  NI  VIRT  RES  SHR S %CPU %MEMTIME+  COMMAND
  4406root  20   0 16.7g  16g  26m S  500 53.0  17958:38 qemu-system-x86

  Guest:
  CPU 0:  0.0% user,  0.0% nice,  0.4% system,  0.0% interrupt, 99.6% idle
  CPU 1:  0.0% user,  0.0% nice,  0.4% system,  0.0% interrupt, 99.6% idle
  CPU 2:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
  CPU 3:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
  CPU 4:  0.4% user,  0.0% nice,  0.0% system,  0.0% interrupt, 99.6% idle
  Mem: 43M Active, 4783M Inact, 1530M Wired, 911M Buf, 9553M Free
  Swap: 3072M Total, 3072M Free

  I have logged this with the appliance vendor and received the response:
  "This is expected behaviour and you will see the same in any case where a 
Guest OS runs over a Host OS.
  Host here has 5 CPUs and it has assigned all of them to Guest. 
  Since the Host is not being shared by any Guest OS; you will always see the 
500% (or the 5 CPUs) given to qemu-system-x86.
  I do see the same in lab and is very much expected"

  This feels fundamentally wrong to me.
  I'm somewhat limited by what can be tested due to the nature of this being an 
appliance rather than a mainstream distro.

  I'm looking for feedback that I can use to push the vendor into
  investigating this issue.

  Versions below.

  Many thanks,
  Gareth


  Host:
  Linux 204a-node 3.10.100-ovp-rt110-WR6.0.0.31_preempt-rt #1 SMP Fri
  Aug 3 01:59:01 PDT 2018 x86_64 x86_64 x86_64 GNU/Linux

  Qemu:
  QEMU emulator version 1.7.2, Copyright (c) 2003-2008 Fabrice Bellard

  Command:
  (Vendor identifying information has been removed)

  /usr/bin/qemu-system-x86_64 \
  -name REMOVED \
  -S \
  -machine pc-i440fx-1.7,accel=kvm,usb=off \
  -m 16384 \
  -realtime mlock=on \
  -smp 5,sockets=5,cores=1,threads=1 \
  -uuid 76277b29-3bd4-4dd4-a705-ed34d6449d6d \
  -nographic \
  -no-user-config \
  -nodefaults \
  -chardev 
socket,id=charmonitor,path=/var/lib/libvirt/qemu/REMOVED.monitor,server,nowait \
  -mon chardev=charmonitor,id=monitor,mode=control \
  -rtc base=utc \
  -no-shutdown \
  -boot strict=on \
  -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \
  -device virtio-scsi-pci,id=scsi0,bus=pci.0,addr=0x17 \
  -netdev tap,fd=22,id=hostnet0,vhost=on,vhostfd=23 \
  -device 
virtio-net-pci,netdev=hostnet0,id=net0,mac=REMOVED,bus=pci.0,addr=0x11 \
  -netdev 
tap,ifname=tap1,script=/etc/vehostd/XXX-em3-ifup,id=hostnet1,vhost=on,vhostfd=24
 \
  -device 
virtio-net-pci,netdev=hostnet1,id=net1,mac=REMOVED,bus=pci.0,addr=0x12 \
  -netdev 
tap,ifname=tap2,script=/etc/vehostd/REMOVED-em4-ifup-SUMMIT,id=hostnet2,vhost=on,vhostfd=25
 \
  -device 
virtio-net-pci,netdev=hostnet2,id=net2,mac=REMOVED,bus=pci.0,addr=0x1c \
  -netdev 
tap,ifname=tap3,script=/etc/vehostd/REMOVED-em4-re-re-ifup,id=hostnet3,vhost=on,vhostfd=26
 \
  -device 
virtio-net-pci,netdev=hostnet3,id=net3,mac=REMOVED,bus=pci.0,addr=0x1d \
  -chardev pty,id=charserial0 \
  -device isa-serial,chardev=charserial0,id=serial0 \
  -chardev tty,id=charserial1,path=/dev/ttyS1 \
  -device isa-serial,chardev=charserial1,id=serial1 \
  -chardev tty,id=charserial2,path=/dev/ttyS2 \
  -device isa-serial,chardev=charserial2,id=serial2 \
  -chardev tty,id=charserial3,path=/dev/ttyS3 \
  -device isa-serial,chardev=charserial3,id=serial3 \
  -device i6300esb,id=watchdog0,bus=pci.0,addr=0x10 \
  -watchdog-action reset \
  -object rng-random,id=rng0,filename=/dev/random \
  -device 
virtio-rng-pci,rng=rng0,max-bytes=1024,period=2000,bus=pci.0,addr=0x1e \
  -smbios type=0,vendor="INSYDE 
Corp.",version=REMOVED,date=11/03/2017,release=1.00 \
  -smbios 
type=1,manufacturer=REMOVED,product=REMOVED,version=REMOVED,serial=VF-NET \
  -device REMOVED-pci,host=:1c:00.0 \
  -device kvm-pci-assign,host=:00:14.0 \
  -device pci-hgcommdev,vmindex=0,bus=pci.0,addr=0x16 \
  -drive 
file=/REMOVED/REMOVED-current.img,if=none,id=drive-virtio-disk0,format=raw,cache=directsync,aio=native
 \
  -device 
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x13,drive=drive-virtio-disk0,id=virtio-disk0,config-wce=off,x-data-plane=on,bootindex=1
 \
  -drive 
file=/REMOVED/REMOVED-var-config.img,if=none,id=drive-virtio-disk1,format=raw,cache=directsync,aio=native
 \
  -device 

[Bug 1794285] Re: 100% Host CPU usage while guest idling

2020-11-11 Thread Thomas Huth
The QEMU project is currently considering to move its bug tracking to another 
system. For this we need to know which bugs are still valid and which could be 
closed already. Thus we are setting older bugs to "Incomplete" now.
If you still think this bug report here is valid, then please switch the state 
back to "New" within the next 60 days, otherwise this report will be marked as 
"Expired". Or mark it as "Fix Released" if the problem has been solved with a 
newer version of QEMU already. Thank you and sorry for the inconvenience.

** Changed in: qemu
   Status: New => Incomplete

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1794285

Title:
  100% Host CPU usage while guest idling

Status in QEMU:
  Incomplete

Bug description:
  Hi,

  We have an appliance that runs a FreeBSD guest on a Yocto-based host via 
qemu-system-x86_64.
  Everything functions fine however the host uses n00% of the CPU (where n = 
#smp) and RAM allocated to it whilst the 1 guest is sat nearing idle.

  Host:
  PID USER  PR  NI  VIRT  RES  SHR S %CPU %MEMTIME+  COMMAND
  4406root  20   0 16.7g  16g  26m S  500 53.0  17958:38 qemu-system-x86

  Guest:
  CPU 0:  0.0% user,  0.0% nice,  0.4% system,  0.0% interrupt, 99.6% idle
  CPU 1:  0.0% user,  0.0% nice,  0.4% system,  0.0% interrupt, 99.6% idle
  CPU 2:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
  CPU 3:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
  CPU 4:  0.4% user,  0.0% nice,  0.0% system,  0.0% interrupt, 99.6% idle
  Mem: 43M Active, 4783M Inact, 1530M Wired, 911M Buf, 9553M Free
  Swap: 3072M Total, 3072M Free

  I have logged this with the appliance vendor and received the response:
  "This is expected behaviour and you will see the same in any case where a 
Guest OS runs over a Host OS.
  Host here has 5 CPUs and it has assigned all of them to Guest. 
  Since the Host is not being shared by any Guest OS; you will always see the 
500% (or the 5 CPUs) given to qemu-system-x86.
  I do see the same in lab and is very much expected"

  This feels fundamentally wrong to me.
  I'm somewhat limited by what can be tested due to the nature of this being an 
appliance rather than a mainstream distro.

  I'm looking for feedback that I can use to push the vendor into
  investigating this issue.

  Versions below.

  Many thanks,
  Gareth


  Host:
  Linux 204a-node 3.10.100-ovp-rt110-WR6.0.0.31_preempt-rt #1 SMP Fri
  Aug 3 01:59:01 PDT 2018 x86_64 x86_64 x86_64 GNU/Linux

  Qemu:
  QEMU emulator version 1.7.2, Copyright (c) 2003-2008 Fabrice Bellard

  Command:
  (Vendor identifying information has been removed)

  /usr/bin/qemu-system-x86_64 \
  -name REMOVED \
  -S \
  -machine pc-i440fx-1.7,accel=kvm,usb=off \
  -m 16384 \
  -realtime mlock=on \
  -smp 5,sockets=5,cores=1,threads=1 \
  -uuid 76277b29-3bd4-4dd4-a705-ed34d6449d6d \
  -nographic \
  -no-user-config \
  -nodefaults \
  -chardev 
socket,id=charmonitor,path=/var/lib/libvirt/qemu/REMOVED.monitor,server,nowait \
  -mon chardev=charmonitor,id=monitor,mode=control \
  -rtc base=utc \
  -no-shutdown \
  -boot strict=on \
  -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \
  -device virtio-scsi-pci,id=scsi0,bus=pci.0,addr=0x17 \
  -netdev tap,fd=22,id=hostnet0,vhost=on,vhostfd=23 \
  -device 
virtio-net-pci,netdev=hostnet0,id=net0,mac=REMOVED,bus=pci.0,addr=0x11 \
  -netdev 
tap,ifname=tap1,script=/etc/vehostd/XXX-em3-ifup,id=hostnet1,vhost=on,vhostfd=24
 \
  -device 
virtio-net-pci,netdev=hostnet1,id=net1,mac=REMOVED,bus=pci.0,addr=0x12 \
  -netdev 
tap,ifname=tap2,script=/etc/vehostd/REMOVED-em4-ifup-SUMMIT,id=hostnet2,vhost=on,vhostfd=25
 \
  -device 
virtio-net-pci,netdev=hostnet2,id=net2,mac=REMOVED,bus=pci.0,addr=0x1c \
  -netdev 
tap,ifname=tap3,script=/etc/vehostd/REMOVED-em4-re-re-ifup,id=hostnet3,vhost=on,vhostfd=26
 \
  -device 
virtio-net-pci,netdev=hostnet3,id=net3,mac=REMOVED,bus=pci.0,addr=0x1d \
  -chardev pty,id=charserial0 \
  -device isa-serial,chardev=charserial0,id=serial0 \
  -chardev tty,id=charserial1,path=/dev/ttyS1 \
  -device isa-serial,chardev=charserial1,id=serial1 \
  -chardev tty,id=charserial2,path=/dev/ttyS2 \
  -device isa-serial,chardev=charserial2,id=serial2 \
  -chardev tty,id=charserial3,path=/dev/ttyS3 \
  -device isa-serial,chardev=charserial3,id=serial3 \
  -device i6300esb,id=watchdog0,bus=pci.0,addr=0x10 \
  -watchdog-action reset \
  -object rng-random,id=rng0,filename=/dev/random \
  -device 
virtio-rng-pci,rng=rng0,max-bytes=1024,period=2000,bus=pci.0,addr=0x1e \
  -smbios type=0,vendor="INSYDE 
Corp.",version=REMOVED,date=11/03/2017,release=1.00 \
  -smbios 
type=1,manufacturer=REMOVED,product=REMOVED,version=REMOVED,serial=VF-NET \
  -device REMOVED-pci,host=:1c:00.0 \
  -device kvm-pci-assign,host=:00:14.0 \
  -device pci-hgcommdev,vmindex=0,bus=pci.0,addr=0x16 \
  -drive