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Questions[gnome-session](ubuntu)

Martin Hope
Pogoattack
Asked: 2020-03-27 13:23:12 +0800 CST
  • 5

How do I change the default xsession for new users which will be added to the system in the future?

I know I can change the last/default session for an existing user by editing the setting XSession= in /var/lib/AccountsService/users/username

But obviously this file is not created yet for new users. It also seems to be not /etc/gdm3/custom.conf

...
[daemon]
DefaultSession=mysession
....

I was not able to locate the default value in 18.04/gdm3

xorg gdm session users gnome-session
Martin Hope
jirislav
Asked: 2019-08-26 23:55:47 +0800 CST
  • 5

The moment I lock my PC, the fans get really noisy, which means there has to be some kind of CPU/GPU load behind the scenes.

I told myself, I need to know, what process is doing this, so I've crafted this audit script using top and awk, which basically takes *.csv filename as input and writes there every second 10 most demanding processes.

#!/bin/bash

SLEEP_SECS=1

DESTFILE="$1"
if ! [[ "${DESTFILE}" =~ \.csv$ ]]; then
        echo "Please provide name of a destination .csv file!"
        exit 1
fi

if ! test -f "${DESTFILE}"; then
        echo "Seconds;PID;User;% CPU;Process Name" > "${DESTFILE}" || exit $?
fi

while true; do
        top -b -o %CPU -n1 | \
                tail -n +8 | \
                head -10 | \
                awk '{print systime() ";" $1 ";" $2 ";" $9 ";" $12}' \
                >> "${DESTFILE}" || exit $?
        echo -n .
        sleep "${SLEEP_SECS}"
done

So I've started the script and locked my screen, fans got really noisy, I waited a little, logged back in, fans got quiet (as if they knew I don't want them to be noisy when I'm not doing anything with the PC :D ) and I've looked into the processes, which got more than 50% of the CPU usage with this command:

gawk --use-lc-numeric -F';' '{if($4 > 50) {print $0}}' cpu-audit.csv

Here's what I've found:

# The header wasn't there OFC, I'm including it just for the convenience
  Seconds ; PID;  User  ;% CPU;Process Name
1566804437;2496;jirislav;106,7;gnome-shell
1566804438;2496;jirislav;106,7;gnome-shell
1566804439;2496;jirislav;100,0;gnome-shell
1566804440;2496;jirislav;100,0;gnome-shell
1566804442;2496;jirislav;93,8;gnome-shell
1566804443;2496;jirislav;100,0;gnome-shell
1566804444;2496;jirislav;100,0;gnome-shell
1566804445;2496;jirislav;100,0;gnome-shell
1566804446;2496;jirislav;106,7;gnome-shell
1566804449;2496;jirislav;131,2;gnome-shell
1566804449;17446;jirislav;68,8;nautilus

What a surprise, gnome-shell was demanding so much resources? What the ...?! I'm not even using it, I use terminator all the time. Ok, so I ran the terminal audit using ps, but it haven't detected the usage as the top did, why not? I'm even listing all the child processes:

$ while true; do ps fu --ppid 2496 --pid 2496; sleep 1; done
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
jirislav  2496  7.3  2.2 2949284 357176 tty2   Rl+  08:49   3:02 /usr/bin/gnome-shell
jirislav  2522  0.7  0.0 322108  8800 tty2     Sl   08:49   0:18  \_ ibus-daemon --xim --panel disable
jirislav  3239  1.2  0.4 855328 67956 tty2     Sl+  08:49   0:30  \_ /usr/bin/python3 /usr/bin/terminato
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
jirislav  2496  7.3  2.2 2949284 356820 tty2   Sl+  08:49   3:02 /usr/bin/gnome-shell
jirislav  2522  0.7  0.0 322108  8800 tty2     Sl   08:49   0:18  \_ ibus-daemon --xim --panel disable
jirislav  3239  1.2  0.4 855328 67956 tty2     Sl+  08:49   0:30  \_ /usr/bin/python3 /usr/bin/terminato
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
jirislav  2496  7.3  2.2 2949284 356820 tty2   Rl+  08:49   3:03 /usr/bin/gnome-shell
jirislav  2522  0.7  0.0 322108  8800 tty2     Sl   08:49   0:18  \_ ibus-daemon --xim --panel disable
jirislav  3239  1.2  0.4 855328 67956 tty2     Sl+  08:49   0:30  \_ /usr/bin/python3 /usr/bin/terminato

I said enough, let's uninstall gnome-shell, I'm not even using it, why let it consume the resources and run noisy fans without my consent? .. Then it hit me, gnome-shell cannot be uninstalled without also uninstalling ubuntu-desktop - let's put aside the question why there is this weird dependency, which doesn't make sense (it could use any other terminal) - the thing I'm wandering about is - what is Ubuntu doing while my session is locked and can I turn this off?

When I'm on meeting, it's really inconvenient.

Note:

I know about the question Ubuntu 18.04 gnome-shell high CPU usage, but none of the proposed solutions work (not that I even expected them to work, because the issue is that mine gnome-shell is using too much resources only when I lock the PC - not when I use it as the linked question describes)

gnome-terminal cpu-load lock-screen gnome-session
Martin Hope
blah
Asked: 2018-10-17 13:10:52 +0800 CST
  • 10

Hello Guys I am facing an odd issue, I am trying to enable the auto-save-session on Ubuntu 18.04.1 LTS, I try to follow some answers already here, but I wasn't able to restore my gnome session.

I use this link to configure my Ubuntu: https://medium.com/@pwaterz/how-to-dual-boot-windows-10-and-ubuntu-18-04-on-the-15-inch-dell-xps-9570-with-nvidia-1050ti-gpu-4b9a2901493d

My kernel version is 4.18.14-041814-lowlatency, and gnome:3.28 before post this question here I had been tried to do the following:

https://www.howtogeek.com/203952/how-to-automatically-remember-running-applications-from-your-last-session-in-ubuntu-14.04/

Review / edit startup programs rembered by "Remember Currently Running Applications"

I am not sure about what I am doing wrong but, if you can give me some help I would appreciate that.

gnome session gnome-session
Martin Hope
zachtib
Asked: 2012-03-27 06:36:57 +0800 CST
  • 6

I'm trying to set up Ubuntu to act as a kiosk running a custom application, and am trying to get a LightDM session built to automatically start it.

Ideally, I'd like to have two sessions available from LightDM. The default would start my application fullscreened, and the other would open a minimal desktop in case any configuration (mostly connecting to a wireless network) needed to be done.

I've done a lot of research over the last week on custom LightDM & Gnome sessions. I've got a custom greeter written for LightDM that can start either session, but I can't figure out how to add a specific application to the Gnome session that is ultimately started without just putting a launcher in the global startup directory, and I don't want to do that since I don't want the application starting when they open "configuration mode".

Another problem I've run into on my current workaround is that the application doesn't fullscreen properly, which makes me think I'm not starting enough of a gnome session (currently it's just metacity, no panel or anything else).

Edit:

I found a solution. See http://www.webupd8.org/2011/11/make-applications-autostart-only-in.html

gnome-session lightdm