plymouthd constantly uses 5% of CPU

[Michael Hanafey]

After a fresh boot plymouthd constantly uses 5% of CPU. Noticed this because my laptop fun will not shut up, something that was not true before some recent routine software update.

This report exists: https://bugs.launchpad.net/ubuntu/+source/kde-workspace/+bug/1240376 , this one is reported fixed. Strange that I to see 5.0% CPU.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: plymouth 0.9.2-3ubuntu13.4
ProcVersionSignature: Ubuntu 4.4.0-119.143-generic 4.4.114
Uname: Linux 4.4.0-119-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.16
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Apr 22 07:58:29 2018
DefaultPlymouth: /usr/share/plymouth/themes/ubuntu-logo/ubuntu-logo.plymouth
InstallationDate: Installed on 2017-02-19 (426 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
MachineType: Dell Inc. Dell System XPS 15Z
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-119-generic root=UUID=f3fecda3-35d3-4e43-a14d-c7d685310d79 ro quiet splash vt.handoff=7
ProcFB:
 0 inteldrmfb
 1 nouveaufb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-119-generic root=UUID=f3fecda3-35d3-4e43-a14d-c7d685310d79 ro quiet splash vt.handoff=7
SourcePackage: plymouth
TextPlymouth: /usr/share/plymouth/themes/ubuntu-text/ubuntu-text.plymouth
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/07/2012
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A12
dmi.board.name: 060G42
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: 0.1
dmi.modalias: dmi:bvnDellInc.:bvrA12:bd09/07/2012:svnDellInc.:pnDellSystemXPS15Z:pvr:rvnDellInc.:rn060G42:rvrA00:cvnDellInc.:ct8:cvr0.1:
dmi.product.name: Dell System XPS 15Z
dmi.sys.vendor: Dell Inc.

[Michael Hanafey (mike-hanafey)]

When plymouthd is burning up 5% of the CPU it also prevents Ctrl-Alt-F6 from giving you a console login. Instead you get a black screen that just echoes what you type.

After "sudo plymouth --quit", the 5% waste is gone and Ctrl-Alt-F6 gives you a console login prompt.

[Michael Hanafey (mike-hanafey)]

This is what the daemon is doing wasting the CPU:

$ time sudo strace -p465 -c
strace: Process 465 attached
^Cstrace: Process 465 detached
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
100.00 0.020412 1 16376 epoll_wait
------ ----------- ----------- --------- --------- ----------------
100.00 0.020412 16376 total

real 0m15.274s
user 0m0.112s
sys 0m0.428s

[CrazyApe84 (crazyape84)]

I have the exact same bug. plymouthd runs at a little under 5% all the time after a reboot. I kill the plymouthd process so it doesn't waste electricity. But it starts up again and does the same thing next boot.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Christopher (cwkeller)]

same here @ 6-7% .

[Jer Ratcliffe (signaljunkie)]

I just noticed this behavior. "sudo plymouth --quit" is my current mitigation, as well.

[Remisa Yousefvand (remisa)]

I did not have this problem until recently changed default theme. Now plymouthd utilizes ~15% cpu.

sudo killall plymouthd

[Christophe Guillon (christophe-guillon)]

Same on Ubuntu 18.04.2, ~ 5% CPU, plymouth package version 0.9.2-3ubuntu13.5

[Christophe Guillon (christophe-guillon)]

Sorry, made a mistake in previous comment (package version given is for 16.04.5).

Actually, the package version on 18.04.2 is plymouth 0.9.3-1ubuntu7.18.04.1

[Alexey Storozhenko (alex4430)]

Well, it's quite frustrating that the bug still persists even on 18.04. I'm using Xubuntu 18.04 with updates installed and the plymouthd had 25% CPU usage on ThinkPad T43p. I found a workaround on how to disable it. The process won't bother you again.
https://askubuntu.com/questions/407131/why-is-plymouthd-crashing-on-startup

[Alexey Storozhenko (alex4430)]

Sorry, that was a wrong link. Here's the correct one:
https://askubuntu.com/questions/766973/16-04-how-to-uninstall-plymouth

[handsome_feng (feng-kylin)]

Same on Ubuntu Kylin 19.04

[Henning (quaxquax)]

See the same bug on my HP Spectre x360 15t.

plymouthd consistently consumes over 20% CPU resources while mostly waiting:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
  487 root 20 0 172488 45328 9900 R 22.6 0.1 156:40.10 plymouthd

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
➜ time sudo strace -p487 -c

strace: Process 487 attached
^Cstrace: Process 487 detached
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
 97.29 0.012121 2 5542 epoll_wait
  1.47 0.000183 6 31 write
  0.80 0.000100 3 31 read
  0.44 0.000055 2 31 31 sendto
------ ----------- ----------- --------- --------- ----------------
100.00 0.012459 5635 31 total
sudo strace -p487 -c 0.14s user 0.29s system 2% cpu 19.240 total

[Henning (quaxquax)]

This is on Ubuntu 18.04.3 LTS

[ConnyLo (webmaster-333)]

Same on Ubuntu 19.10, ~ 5% CPU,
plymouth package version 0.9.4git20190712-0ubuntu4.1

[Przemek Peron (przemekperon)]

Same problem on Xubuntu 20.04

[Marcin Sochacki (wanted)]

Same problem on a fresh install of Ubuntu 19.10 x86_64 on a Toshiba Satellite U405. Another curiosity is that plymouth fails to display anything on the splash screen, it is just black until the system fully boots up.

Removing splash from /etc/default/grub disables plymouth.