Ubuntu 26.10 changes how the system choose which processes are killed when memory runs low, making a rogue browser tab is less likely to punt you back to the login screen.
When your system runs out of memory, the kernel’s out-of-memory (OOM) killer kicks in, terminating processes to recover some.
The issue is that doesn’t always kill the right things.
By default, many apps and critical desktop services share the same priority score. When the OOM killer is choosing its victim target, it looks at their OOM scores, not “what’s using the most memory”.
Firefox and GNOME Shell, for example, share the same priority status. If memory pressure increases, the OOM killer may decide to terminate GNOME Shell to free up memory rather than the the process causing runaway memory requirements.
I regularly encounter this myself in Ubuntu VMs if I try to do too many things (with too many Firefox tabs open): rather than OOM nuking an app, it kills GNOME Shell instead – but I’d much rather a tab crash than my entire desktop session.
Ubuntu 26.10 makes changes to mitigate this.
Canonical’s Jean Baptiste Lallement says “the goal is simply to preserve the desktop session where possible” by terminating apps before core session services. To do this, it’s lowered the OOM scores for desktop processes so they’re less likely to be nixed.
Ubuntu 26.10 also stops systemd-oomd being able to kill user sessions as it doesn’t use the same OOM priority scores as the kernel, and important desktop services could still be nixed based on memory pressure requirements.
These changes will improve how Ubuntu copes when memory runs out, but Lallement calls it “a first step” that “does not make Ubuntu immune to OOM conditions”. More granular OOM policies for desktop services and apps are planned.
Ubuntu 26.10 is released on Thursday 15 October, 2026, but if you plan to test drive the beta that’s due on Thursday 24 September, these changes will be there – not that you’ll notice them, hopefully!
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