Useful Stuff¶

Symbolic Link to Windows Folder¶

ln -s /media/sigma_ibo/Windows/Dokumente\ und\ Einstellungen/Pamibr/Desktop/Masterarbeit/ /home/sigma_ibo/Desktop/
Symbolic Link to Windows Folder

Mount Windows partition Desktop¶

sudo nano /etc/fstab
At the end of the file, add: UUID=0E58A36658A34B73 /home/sigma_ibo/Desktop ntfs defaults 0 0, it looks like this
reboot

How to Extract (Unzip) tar.xz File¶

How to Extract (Unzip) tar.xz File

Launch programs after startup¶

nano /home/sigma_ibo/startup.sh
chmod +x /home/sigma_ibo/startup.sh
File: startup.sh
Configure Startup Apps

Install gnome¶

sudo apt install gnome-shell-extension-ubuntu-dock

Desktop folders not visible¶

sudo apt install ubuntu-desktop

Windows 11 on QEMU and display settings¶

Install Windows 11 in KVM on Ubuntu 22.04
Execute virtio-win-guest-tools in VM
Windows 10 VM shows 100% CPU
QEMU settings: QEMU, XML win11
Windows 10 VM Settings

Remove keyring from Edge¶

To stop being prompted to unlock the ‘default’ keyring on boot, set a blank password for the keyring. - Open the utility “Passwords & Keys”. If not installed: sudo apt-get install seahorse
- Right-click the “Login” folder and select “Change Password”. - Enter your old password and leave the new password blank.

See how many cores you have¶

nproc or cat /proc/cpuinfo | grep processor | wc -l or cat /proc/cpuinfo | grep 'core id' or lscpu

start_qemu.sh from everywhere¶

Script start_qemu.sh needs to be in /home/sigma_ibo/Desktop/Masterarbeit/masterthesis-documentation/QEMU/.

sudo nano ~/.bashrc
export PATH=$PATH:/home/sigma_ibo/Desktop/Masterarbeit/documentation/resources/QEMU/

Add konsole to replace console¶

nautilus-open-any-terminal

sudo apt install python3-nautilus python3-pip gir1.2-gtk-4.0
pip install nautilus-open-any-terminal
nautilus -q
sudo apt remove nautilus-extension-gnome-terminal
gsettings set com.github.stunkymonkey.nautilus-open-any-terminal terminal konsole
gsettings set com.github.stunkymonkey.nautilus-open-any-terminal keybindings '<Ctrl><Alt>t'
gsettings set com.github.stunkymonkey.nautilus-open-any-terminal new-tab true
gsettings set com.github.stunkymonkey.nautilus-open-any-terminal flatpak system

Change default terminal with right-click option "Open in Terminal" in file manager

SSH ohne Passwort¶

Um eine SSH-Verbindung von Ihrem Host-Computer zu Ihrem Gast-Computer (oder Server) herzustellen, können Sie die folgenden Schritte ausführen:

Generieren Sie ein SSH-Schlüsselpaar auf Ihrem Host-Computer. Sie können dies mit dem Befehl ssh-keygen tun. Sie werden aufgefordert, ein Passwort einzugeben, aber Sie können einfach Enter drücken, um kein Passwort zu setzen (obwohl dies aus Sicherheitsgründen nicht empfohlen wird).

ssh-keygen

Kopieren Sie Ihren öffentlichen Schlüssel auf den Gast-Computer. Sie können dies mit dem Befehl ssh-copy-id tun. Ersetzen Sie benutzername durch Ihren Benutzernamen auf dem Gast-Computer und ip_address durch die IP-Adresse des Gast-Computers.

ssh-copy-id root@192.168.1.51

Stellen Sie eine SSH-Verbindung zum Gast-Computer her. Sie können dies mit dem Befehl ssh tun. Ersetzen Sie wieder benutzername und ip_address durch Ihren Benutzernamen und die IP-Adresse des Gast-Computers.

ssh root@192.168.1.51

Nachdem Sie diese Schritte ausgeführt haben, sollten Sie in der Lage sein, sich ohne Passwort bei Ihrem Gast-Computer anzumelden.

Wenn Sie den ssh-copy-id Befehl verwenden, wird Ihr öffentlicher SSH-Schlüssel in der Datei ~/.ssh/authorized_keys auf dem Gast-Computer (dem Computer, zu dem Sie eine SSH-Verbindung herstellen) gespeichert.

Jede Zeile in dieser Datei repräsentiert einen öffentlichen Schlüssel, der für die Authentifizierung zugelassen ist. Wenn Sie also mehrere Schlüssel haben, die Sie verwenden, um sich bei diesem Computer anzumelden, wird jeder Schlüssel als separate Zeile in dieser Datei angezeigt

Check on which CPU a task is running¶

ps -eo pid,psr,comm | grep <name>

Limit WSL2 resources¶

Edit the WSL config to limit the memory usage as mentioned here.

#turn off all wsl instances such as docker-desktop
wsl --shutdown
notepad "$env:USERPROFILE/.wslconfig"

Set the values you want for CPU core and Memory:

[wsl2]
memory=3GB   # Limits VM memory in WSL 2 up to 3GB
processors=2 # Makes the WSL 2 VM use two virtual processors

Connect to hardware Salamander 4¶

ssh root@192.168.1.244

Boot parameters¶

cat /proc/cmdline

Stress the CPUs¶

stress -c $(nproc)

Check cpu MAXMHZ, MINMHZ, CURRENT MHZ¶

$ lscpu --all --extended
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE    MAXMHZ   MINMHZ      MHZ
  0    0      0    0 0:0:0:0          yes 5000,0000 400,0000 2900.000
  1    0      0    1 4:4:1:0          yes 5000,0000 400,0000 2900.000
  2    0      0    2 8:8:2:0          yes 5200,0000 400,0000 2900.000
  3    0      0    3 12:12:3:0        yes 5200,0000 400,0000 4174.117
  4    0      0    4 16:16:4:0        yes 5000,0000 400,0000 2900.000
  5    0      0    5 20:20:5:0        yes 5000,0000 400,0000 2900.000
  6    0      0    6 24:24:6:0        yes 4000,0000 400,0000 2926.742
  7    0      0    7 25:25:6:0        yes 4000,0000 400,0000 2900.000
  8    0      0    8 26:26:6:0        yes 4000,0000 400,0000 2900.000
  9    0      0    9 27:27:6:0        yes 4000,0000 400,0000 2900.000
 10    0      0   10 28:28:7:0        yes 4000,0000 400,0000 3332.776
 11    0      0   11 29:29:7:0        yes 4000,0000 400,0000 2900.000
 12    0      0   12 30:30:7:0        yes 4000,0000 400,0000 2900.000
 13    0      0   13 31:31:7:0        yes 4000,0000 400,0000 3218.336

See threads of a task¶

sigma_ibo@sigma-ibo:~$ ls /proc/464458/task | wc -l
6
sigma_ibo@sigma-ibo:~$ htop -H -p 464458

Thread priorities¶

Set / Manipulate Real Time Attributes of a Linux Process
Full list of all threads on the system with process id, thread id, short name, scheduling policy, nice value and realtime-priority. ps reports SCHED_DEADLINE as DLN, SCHED_OTHER as TS, SCHED_BATCH as B, SCHED_IDLE as IDL, SCHED_FIFO as FF and SCHED_RR as RR.

ps axHo psr,pid,lwp,args,policy,nice,rtprio

All the tasks on CPU 13

ps axHo psr,pid,lwp,args,policy,nice,rtprio | awk '$1 == 13'

All rt processes

ps axHo psr,pid,lwp,args,policy,nice,rtprio | grep -P '\s[0-9]+\s*$'
ps axHo psr,pid,lwp,args,policy,nice,rtprio | awk '$NF ~ /^[0-9]+$/' | sort -k4,4 -V > rt_processes.txt

Set all threads of a process to a real-time priority

ps -T -p $(pgrep -f "qemu-system-x86_64 -M pc,ac") | awk '{print $2}' | tail -n +2 | xargs -I {} sudo chrt -f -p 10 {}

Watch it

watch -d -c -n 1 "ps axHo psr,pid,lwp,args,policy,nice,rtprio | awk '\$1 == 4'"

Test suite: rt-tests¶

An Analysis of the Real-Time Performance of Linux Kernels The rt-tests test suite contains programs to test various real-time Linux features; more details are available here. The step-by-step procedure to install the rt-tests suite from the source is given below.

First, you need to install the libraries:

sudo apt-get install build-essential libnuma-dev

Next, clone the code and build from the source:

git clone git://git.kernel.org/pub/scm/utils/rt-tests/rt-tests.git
cd rt-tests
git checkout stable/v1.0
make all
make install

Useful Not needed¶

Add more CPUs to QEMU virtual machine with -smp option¶

The -smp option specifies the number of CPUs

Replace n with the number of CPUs you want to add. For example, if you want to add 4 CPUs, you would use -smp cpus=4.

After making these changes, the specified number of CPUs will be available when you boot your Yocto image with this script.

exec qemu-system-x86_64 -M pc,accel=kvm -kernel ./bzImage \
-m 2048 -drive file=salamander-image-sigmatek-core2.ext4,format=raw,media=disk \
-append "console=ttyS0 console=tty1 root=/dev/sda rw panic=1 sigmatek_lrt.QEMU=1 ip=dhcp rootfstype=ext4 \
-net nic,model=e1000,netdev=e1000 -netdev bridge,id=e1000,br=nm-bridge \
-fsdev local,security_model=none,id=fsdev0,path=drive-c -device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_>
-drive if=pflash,format=qcow2,file=ovmf.code.qcow2 \
-smp cpus=n \
-no-reboot -nographic

Check with: cat /sys/devices/system/cpu/online

root@sigmatek-core2:~# cat /sys/devices/system/cpu/online
0-9

Isolate CPUs in QEMU with isolcpus¶

To use isolcpus in a Yocto image, you need to add it to the kernel command line parameters. In your case, these parameters are specified in the -append option in your QEMU command. Add isolcpus=x,y,z. Replace x,y,z with the CPU cores you want to isolate. For example, if you want to isolate cores 0, 1 and 2, you would use isolcpus=0,1,2.

exec qemu-system-x86_64 -M pc,accel=kvm -kernel ./bzImage \
-m 2048 -drive file=salamander-image-sigmatek-core2.ext4,format=raw,media=disk \
-append "console=ttyS0 console=tty1 root=/dev/sda rw panic=1 sigmatek_lrt.QEMU=1 ip=dhcp rootfstype=ext4 isolcpus=0,1,2" \
-net nic,model=e1000,netdev=e1000 -netdev bridge,id=e1000,br=nm-bridge \
-fsdev local,security_model=none,id=fsdev0,path=drive-c -device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_>
-drive if=pflash,format=qcow2,file=ovmf.code.qcow2 \
-smp cpus=n \
-no-reboot -nographic

Check with: cat /sys/devices/system/cpu/isolated

root@sigmatek-core2:~# cat /sys/devices/system/cpu/isolated
0-2

Gid PID Of processes¶

Start latency and write output to latency_output.txt: latency -T 60 > latency_output.txt 2>&1 &
Get ID of xenomai task: ps aux | grep latency

root@sigmatek-core2:~# latency -T 60 > latency_output.txt 2>&1 &
[1] 557
root@sigmatek-core2:~# ps aux | grep latency
root       557  0.0  0.6  14040 12852 ttyS0    SLl  11:34   0:00 latency -T 60
root       563  0.0  0.0   3256  1148 ttyS0    S+   11:34   0:00 grep latency

Assign tasks to the isolated CPUs¶

To assign these latency tasks to the isolated CPUs, you can use the taskset command with the process ID (PID) of each latency task. For example, if you want to assign the latency task with PID 536 to CPU 1, you would use:

taskset -pc x abc

Remember to replace abc with the actual PID of the latency task. You can repeat this process for each latency task and each isolated CPU.

Kill processes¶

Kill processes with kill x

^M error message¶

The error message you're seeing is typically caused by a mismatch in line endings. Scripts that have been edited or created on Windows use a different line ending (\r\n) than Unix/Linux (\n). The ^M in the error message is a visual representation of \r (carriage return), which is not expected or understood by the Linux shell.

You can convert the line endings of your script to the Unix format using a tool like dos2unix. Here's how you can do it:

sudo apt-get install dos2unix  # Install dos2unix tool
dos2unix <file>

Split too long Prompt¶

ChatGPT PROMPTs Splitter

Configure ip addresses¶

Configure PC to 10.10.1.1.
Salamander Gateway set to 10.10.1.229

Ubuntu VM on virtual machine manager¶

After giving the VM access to the vsocket, and installing trace-cmd along with dependancies, run trace-cmd agent. Now, the guest is able to negotiate with host about timestamp synchronization. After running ./start_kernelshark.sh, we can view KVM Combo plots