Re: [PATCH v2 00/23] mm: BPF OOM

Michal Hocko
2025-11-03T18:18:34Z

On Sun 02-11-25 12:53:53, Roman Gushchin wrote:
> Michal Hocko <mhocko@suse.com> writes:
>
> > On Mon 27-10-25 16:17:03, Roman Gushchin wrote:
> >> The second part is related to the fundamental question on when to
> >> declare the OOM event. It's a trade-off between the risk of
> >> unnecessary OOM kills and associated work losses and the risk of
> >> infinite trashing and effective soft lockups. In the last few years
> >> several PSI-based userspace solutions were developed (e.g. OOMd [3] or
> >> systemd-OOMd [4]). The common idea was to use userspace daemons to
> >> implement custom OOM logic as well as rely on PSI monitoring to avoid
> >> stalls. In this scenario the userspace daemon was supposed to handle
> >> the majority of OOMs, while the in-kernel OOM killer worked as the
> >> last resort measure to guarantee that the system would never deadlock
> >> on the memory. But this approach creates additional infrastructure
> >> churn: userspace OOM daemon is a separate entity which needs to be
> >> deployed, updated, monitored. A completely different pipeline needs to
> >> be built to monitor both types of OOM events and collect associated
> >> logs. A userspace daemon is more restricted in terms on what data is
> >> available to it. Implementing a daemon which can work reliably under a
> >> heavy memory pressure in the system is also tricky.
> >
> > I do not see this part addressed in the series. Am I just missing
> > something or this will follow up once the initial (plugging to the
> > existing OOM handling) is merged?
>
> Did you receive patches 11-23?

OK, I found it. Patches 11-23 are threaded separately (patch 11
with Message-ID: <20251027232206.473085-1-roman.gushchin@linux.dev> doesn't
seem to have In-reply-to in header) and I have missed them previously. I
will have a look in upcoming days.

--
Michal Hocko
SUSE Labs