Large number of notifications slow down whole panel

[minhdanh]

What Happened?

At boot wingpanel would take about nearly 1 miniute to appear (when the dock and desktop has appeared). After that it randomly becomes very slow to respond to click (to application menu, time and date, or power icon), may be 5 minutes after the click.
At this moment when checking htop, I can see it's consuming a high amount of CPU:

(The CPU of wingpanel is actually always 100% when it doesn't respond)

Steps to Reproduce

It happens at boot time, and randomly becomes slow to respond after that. I'm not sure how to find a consistence way to reproduce.

Expected Behavior

Wingpanel displays as soon the desktop is shown, and respond quickly to mouse click (and ctrl space)

OS Version

6.x (Odin)

Software Version

Latest release (I have run all updates)

Log Output

I tried to use this command:

killall io.elementary.wingpanel && io.elementary.wingpanel

And could see these lines (new lines keep being added):
```shell
(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:23.729: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-G0N6D1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:23.739: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-UYK2D1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:23.749: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-V0V7D1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:23.760: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-7T53D1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:23.770: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-2RQ9D1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:23.970: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-SD13D1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:23.984: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-Y6B7D1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:24.000: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-IT4UD1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:24.022: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-KAWPD1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:24.677: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-IWOJB1.png”: No such file or directory

(io.elementary.wingpanel:386011): io.elementary.wingpanel.notifications-CRITICAL **: 10:18:24.711: NotificationEntry.vala:79: Unable to mask image: Failed to open file “/tmp/wingpanel-VPI9D1.png”: No such file or directory

(io.elementary.wingpanel:399121): io.elementary.wingpanel.bluetooth-CRITICAL **: 10:23:42.919: Manager.vala:58: Error calling StartServiceByName for org.bluez: Failed to activate service 'org.bluez': timed out (service_start_timeout=25000ms)
** Message: 10:25:45.733: DBusService.vala:64: Service registration suceeded

[canopusStar]

Are you running elementary OS 6.1 Jólnir? Check using lsb_release -a as I have had this Wingpanel issue since that release update. My Wingpanel versions in AppCentre also supposedly updated but is reported as 3.0.1 and 3.0.2 in the AppCentre.

$ lsb_release -a
No LSB modules are available.
Distributor ID: Elementary
Description: elementary OS 6.1 Jólnir

My output for Killall Wingpanel:

$ killall io.elementary.wingpanel && io.elementary.wingpanel
Failed to register: GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying
$

[minhdanh]

Here's mine:

No LSB modules are available.
Distributor ID: Elementary
Description:    elementary OS 6.1 Jólnir
Release:        6.1
Codename:       jolnir

[wouterrutgers]

No LSB modules are available.
Distributor ID: Elementary
Description:    elementary OS 6.1 Jólnir
Release:        6.1
Codename:       jolnir

What I've noticed is that it becomes very unresponsive when I have a lot of unread notifications (500+, slack stacks up quick!). After clearing all notifications, it becomes responsive again.

[minhdanh]

If I create a new account and login with that account, at least I don't see wingpanel slow to start. So maybe it has something to do with my config files?

[cassidyjames]

@minhdanh do you also have a lot of notifications on your main account?

[minhdanh]

@cassidyjames Yes, I do. I'm not sure how many but I haven't cleared the notifications since I installed the OS. I've just cleared all notifications. Let see if it's going to happen again.

[minhdanh]

After clearing the notifications, wingpanel can start very fast after booting.

[janxkoci]

Is there a usability reason why notifications even survive between sessions?

[teamcons]

Necromancing this issue as an user on discord (amalchandran) encountered it:

System info
OS: Linux 6.5 elementary OS 7.1 Horus 7.1 Horus
CPU: (16) x64 AMD Ryzen 7 5800H with Radeon Graphics
Memory: 19.81 GB / 27.25 GB

Steps reproduce the issue (exact issue happened for me).
enable DND mode. continue using with apps like slack, discord, etc that creates notification
after some months you will see the wingpanel takes longer to load on restart

the fast way to reproduce is to use notify-send cli,
create notifications kill and restart wingpanel see its starts using more cpu on restarting
or try opening the application and search see its working fine or not (it will not work)

i will check soon whether this is still an issue in 8

#### EDIT ####
After a few sessions of DND coupled with:
$> while true; do notify-send "yoy" ; done

wingpanel is aggressively slow, and even opening the notification indicator can cause a crash
search in application menu still seem to work without issue

Maybe it would be wise to have notifications decay. I regularly have to clean up there, and piling notifications makes it more difficult to triage the recent and relevant of the obsolete and cluttery

This would both fix the issue and make the indicator more efficient
Mayhaps the delay of notification decay could be set in housekeeping ? Or Notifications ? (where one would look first)