Disabling CONFIG_COMPACTION

["Pratoussy, Martin (GE Vernova)" <Martin.PRATOUSSY@xxxxxx>]

Hello,

 

We are facing an issue regarding Linux kernel 5.10.153. When we try to allocate huge amount of memory, we eventually run prematurely out of memory.

The bug has been discovered as follows: although “free” and “top” commands would show 40 MB of free memory, sending a 32 MB file through SFTP into RAM cache will lead to an OOM error before finishing the transfer.

It has been noted that the command “echo 1 > /prox/sys/vm/compact_memory” leads into the very same behavior of the kernel. Disabling CONFIG_COMPACTION is surprisingly resolving the allocation issue and we are trying to understand why.

 

You will find below more information about the error we are facing:

• Architecture: Nios2
• Total RAM size: 64 MB
• Available RAM size when error occurs: ~17MB
• Error message: “Huh VM_FAULT_OOM leaked out to the #PF handler. Retrying PF”

 

Would you have any idea of what is happening?

 

You will find attached the .config of our kernel.

 

Best regards,

 

Martin Pratoussy

Embedded software engineer apprentice – Electronics & High Voltage Digital, Grid Solutions

GE Renewable

M +33 (0)7 82 54 60 81

www.gegridsolutions.com

21, Rue Cyprian | 69100 Villeurbanne  | France

 

Attachment: ATT34402.config
Description: ATT34402.config