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PSA: If your Jellyfin is having high memory usage, add MALLOC_TRIM_THRESHOLD_=100000 to environment (lemm.ee)
submitted 3 days ago* (last edited 2 days ago) by [email protected] to c/[email protected]
7 comments fedilink hide all child comments
 

Many users reported high memory/RAM usage, some 8GB+.

In my case gone from 1.5GB+ to 400MB or less on Raspberry Pi 4.

Adding MALLOC_TRIM_THRESHOLD_=100000can make a big difference.

With Docker:
Add to your docker-compose.yml and docker compose down && docker compose up -d

...
environment:
  - MALLOC_TRIM_THRESHOLD_=100000
...

With systemd:
Edit /etc/default/jellyfin change the value of MALLOC_TRIM_THRESHOLD_ and restart the service

# Disable glibc dynamic heap adjustment
MALLOC_TRIM_THRESHOLD_=100000

Source: https://github.com/jellyfin/jellyfin/issues/6306#issuecomment-1774093928

Official docker,Debian,Fedora packages already contain MALLOC_TRIM_THRESHOLD_.
Not present on some docker images like linuxserver/jellyfin

Check is container (already) have the variable
docker exec -it jellyfin printenv | grep MALLOC_TRIM_THRESHO LD_

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[–] [email protected] 5 points 2 days ago* (last edited 2 days ago) (1 children)

It's bad form to just say "set this variable to this value" without any explanation about what that variable does and why that value helped.

Your configuration may not work or may be detrimental for others.

[–] [email protected] -1 points 2 days ago (1 children)

If you click the source linked, you can read through all the details.

[–] [email protected] 3 points 1 day ago

The linked source also doesn’t explain what the env variable actually does or why it fixes anything.

[–] [email protected] 4 points 2 days ago (1 children)

PS: Reddit doesn't allow edit post titles, needed to repost

But this is Lemmy.

[–] [email protected] 1 points 2 days ago

OP didn't update their repost bot to understand what it's reposting.

[–] [email protected] 1 points 3 days ago (1 children)

What does it do?

[–] [email protected] -1 points 3 days ago

The value of this tunable is the minimum size (in bytes) of the top-most, releasable chunk in an arena that will trigger a system call in order to return memory to the system from that arena.

https://www.gnu.org/software/libc/manual/html_node/Memory-Allocation-Tunables.html

MALLOC_MMAP_THRESHOLD_ is an environment variable that sets the size threshold for using the mmap system call to allocate memory instead of using the heap.

  • Default: 128 KiB
  • Behavior:
    • If a memory request is ≥ 128 KiB, mmap is used.
    • If < 128 KiB, the heap is used.
  • Purpose:
    • Helps manage large memory allocations more efficiently.
    • Can be adjusted to optimize performance for specific applications.