[Bug 1799265] Re: avahi-daemon high cpu, unusable networking

[Trent Lloyd]

Hi Matt,

Thanks for the report. I'd like to profile avahi using perf to get
information on what functions are being executed. Could you run the
following commands to generate such data?

If you are unsure about any of this feel free to ask.


echo "deb http://ddebs.ubuntu.com $(lsb_release -cs) main restricted universe multiverse" | sudo tee -a /etc/apt/sources.list.d/ddebs.list
sudo apt update
sudo apt install linux-tools-generic ubuntu-dbgsym-keyring linux-cloud-tools-generic
sudo apt update
sudo apt install avahi-daemon-dbgsym libavahi-common3-dbgsym libavahi-core7-dbgsym libavahi-glib1-dbgsym libc6-dbgsym libcap2-dbgsym libdaemon0-dbgsym libdbus-1-3-dbgsym libecore-avahi1-dbgsym libexpat1-dbgsym libgcrypt20-dbgsym libgpg-error0-dbgsym liblz4-1-dbgsym liblzma5-dbgsym libnss-systemd-dbgsym libsystemd0-dbgsym 

then to record a profile:

sudo perf record -p $(cat /run/avahi-daemon/pid) -g -- sleep 60

This will exit after 60 seconds, then generate perf script output:

sudo perf script > avahi-perf.script.txt
sudo perf report -n --stdio > avahi-perf.report.txt

And then upload the resulting avahi-perf.script.txt and avahi-
perf.report.txt for analysis.


You'll want to make sure avahi is using 100%+ CPU at the time you do this.

Lastly from the same bootup, can you please collect the log info from journalctl:
journalctl -u avahi-daemon --no-pager --no-tail > avahi-journal.txt


Thanks for reporting the bug! Hopefully we can figure it out.

In the mean time if you want to disable avahi you can try this:
sudo systemctl disable avahi-daemon.socket avahi-daemon
sudo systemctl stop avahi-daemon.socket avahi-daemon

(to re-enable change to start and enable)

Regards,
Trent

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to avahi in Ubuntu.
https://bugs.launchpad.net/bugs/1799265

Title:
  avahi-daemon high cpu, unusable networking

Status in avahi package in Ubuntu:
  New

Bug description:
  Currently running Kubuntu 18.10, Dell XPS 13 9350

  Since updating from Kubuntu 18.04 to 18.10, the avahi-daemon has been
  consistently hampering network performance and using CPU for long
  periods of time.

  When booting machine from off state, avahi-daemon uses an entire CPU
  at max load for approx 10 minutes. During this time, internet
  connectivity via wifi is essentially unusable. The wifi connection is
  good, but it seems that http transactions are cutoff mid-way so no
  webpage is able to load.

  When waking from sleep, the avahi-daemon causes similar symptoms, but
  with less than 1 full cpu usage, and with somewhat less degraded
  network performance, but still quite unusable.

  I have never had issues with avahi prior to the 18.10 upgrade, so I am
  fairly confident the issue is rooted in that change.

  ProblemType: Bug
  DistroRelease: Ubuntu 18.10
  Package: avahi-daemon 0.7-4ubuntu2
  ProcVersionSignature: Ubuntu 4.18.0-10.11-generic 4.18.12
  Uname: Linux 4.18.0-10-generic x86_64
  ApportVersion: 2.20.10-0ubuntu13
  Architecture: amd64
  CurrentDesktop: KDE
  Date: Mon Oct 22 10:00:34 2018
  InstallationDate: Installed on 2017-07-24 (455 days ago)
  InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
  ProcEnviron:
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=en_US.UTF-8
   LD_PRELOAD=<set>
   SHELL=/bin/bash
  SourcePackage: avahi
  UpgradeStatus: Upgraded to cosmic on 2018-10-20 (2 days ago)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1799265/+subscriptions