Configuring memory allocation¶

To configure memory allocation, you must tune the memory_limit attributes of high and max for the QM partition.

The max value represents the maximum limit for memory use in the QM partition. If QM processes attempt to exceed the max limit, the Out of Memory (OOM) killer is initiated. The high value is the memory threshold that the kernel tries not to exceed. If QM processes reach the high limit, the kernel will proactively release memory.

Prerequisites

Podman is installed.
The automotive-image-builder tool is installed.
A custom manifest file with a QM partition, such as the manifest file that you created in Embedding containerized applications in the QM partition.

Procedure

In your manifest file, configure the memory_limit attributes max and high to 40% and 35%, respectively:
Example memory_limit configuration
```
qm:
  memory_limit:
    max: 40%
    high: 35%
```

Verification

Build a disk image:

Example aib-dev build command

$ aib-dev build \
    --distro autosd10 \
    --target qemu \
    <my_manifest>.aib.yml \
    <my_image>.qcow2

Run the image:
Example Automotive Image Runner command
```
$ air --nographics <my_image>.qcow2
```
After the image starts, log in as root using the password password.
Use the systemctl show command to display the MemoryMax value generated by the max option you set in your manifest:
Verify QM partition MemoryMax
```
[root@localhost ~]# systemctl show qm | grep MemoryMax
MemoryMax=823468032
```
Use the systemctl show command to display the MemoryHigh value generated by the high option you set in your manifest:
Verify QM partition MemoryHigh
```
[root@localhost ~]# systemctl show qm | grep MemoryHigh
MemoryHigh=720535552
```

Review the contents of the drop-in file generated by your manifest using the cat command:

Show drop-in configuration file contents

[root@localhost ~]# cat /usr/share/containers/systemd/qm.container.d/10-automotive.conf
[Service]
MemoryMax=40%
MemoryHigh=35%
CPUWeight=idle

[Container]

Additional resources