Re: Hard system lock-ups when using encrypted swap and RAM is exhausted

[Zdenek Kabelac <zkabelac@redhat.com>]

Dne 10. 01. 26 v 8:09 Askar Safin napsal(a):
> On Fri, Jan 2, 2026 at 4:47 PM Mikulas Patocka <mpatocka@redhat.com> wrote:
>> Hi
>>
>> Dm integrity doesn't need to allocate memory when processing I/O requests
> 
> Thank you for answer!
> 
> Unfortunately, my experience shows the opposite thing.
> 
> [[ TL;DR: my experience shows that dm-integrity journaled mode is buggy, and
> non-journaled mode is not. I. e. journaled mode seems to allocate memory, and
> this causes temporary (for 4 minutes) lockups (on high specced
> machine). Or maybe journaled mode has
> some another bug, which causes such lockups. They are not reproducible in
> non-journaled mode. ]]


I think it's important to decipher what and how it's blocked - I kind of 
suspect your system is not blocked on 'dm-integrity' itself - rather some 
userland app being swapped out of CPU.

You probably do need to configure your systemd-oom killer to prevent getting 
your system to it's knees - if you run your system to the moment whether it 
takes 4 minutes to run a task - there is something seriously wrong with the 
configuration - as OOM is supposed to kill userland RAM hogging task much 
earlier (possibly even your overbloated google chrome APP if it run out of 
bounds).

So I think you should also show whole device tree of your system and some more 
information - so there is even 'remote' chance trying to reproduce your scenario.

Regards

Zdenek