cups-browsed high CPU usage

[Francois Thirioux]

Hi,

Using Lunar wifi connected to an enterprise network.
cups-browsed uses a lot of CPU %, I need to kill it to save my battery.
2.0rc1-0ubuntu1

[Launchpad Janitor (janitor)]

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

[Addison (addison912)]

I'm having the same issue. This is the second day in a row I've had to kill cups-browsed because it was pinned at 100% CPU utilization. The issue started after upgrading to Lunar. I'm also connected to the network via wifi.

[Ryan C. Underwood (nemesis-icequake)]

By stracing, I can see poll() being called in a busy loop with a timeout of 0. The backtrace for these bad poll() calls points to glib (this is a version rebuilt with nostrip and noopt:
Thread 1 "cups-browsed" hit Breakpoint 4, __GI___poll (fds=0x555875c39f20, nfds=2, timeout=0) at ../sysdeps/unix/sysv/linux/poll.c:27
27 in ../sysdeps/unix/sysv/linux/poll.c
(gdb) bt
#0 __GI___poll (fds=0x555875c39f20, nfds=2, timeout=0) at ../sysdeps/unix/sysv/linux/poll.c:27
#1 0x00007fe75bb690ee in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007fe75bb0dbdf in g_main_loop_run () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x0000555875aa9d41 in main (argc=1, argv=0x7fffa0d9efd8) at daemon/cups-browsed.c:14077

The two fds being polled in this busy loop are:
lrwx------ 1 cups-browsed lpadmin 64 May 1 14:29 5 -> 'anon_inode:[eventfd]'
lrwx------ 1 cups-browsed lpadmin 64 May 1 14:29 6 -> 'socket:[9085882]'

[Pirouette Cacahuète (lissyx)]

same for me, I have not verified what was causing it, this is the first time it happens for me though I upgraded to 23.04 a few weeks ago already. Connected over WiFi, as someone mentions.

[hil liao (hilliao)]

The problem is critical to servers or systems that have peak usage at times that consumes high CPUs. The motherboard's Ethernet port is connect to a 1 gbp/s switch. The wifi is used as a hot spot.

on a AMD Ryzen 5 3600 computer, I observe the same. Here are some specs:
Motherboard: https://www.newegg.com/msi-b450m-pro-vdh-max/p/N82E16813144265
RAM: 8GB
Disk: Sk Hynix p31 Gold 1TB
Description: Ubuntu 23.04

`sudo killall -v cups-browsed` does not kill the process but makes it use even more CPU. The correct method is `service cups-browsed stop`. That will take about 1 minute. If you need the daemon service, you can start it later. But it may go crazy again!

[Angel D. Segarra (angel-segarra)]

I have again experienced this after the update that was intended to address this. Just today I found cups-browsed using 100% CPU. This is on 23.04 Lunar with 2.0~rc1-0ubuntu1.1 cups-browsed.

[Guy Korland (gkorland)]

I see 200% CPU usage on Ubuntu 23.04 (Ubuntu Mate)

Linux guy-ThinkPad-T14-Gen-2i 6.2.0-31-generic #31-Ubuntu SMP PREEMPT_DYNAMIC Mon Aug 14 13:42:26 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

[Yang Ma (mayangluon)]

I also see a 200% CPU usage on Ubuntu 23.10 (Kubuntu)

Linux HP-ZBook 6.5.0-14-generic #14-Ubuntu SMP PREEMPT_DYNAMIC Tue Nov 14 14:59:49 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux