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[109.81.31.109]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b7077cfa966sm1093828666b.65.2025.11.03.10.18.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Nov 2025 10:18:32 -0800 (PST) Date: Mon, 3 Nov 2025 19:18:31 +0100 From: Michal Hocko To: Roman Gushchin Cc: Andrew Morton , linux-kernel@vger.kernel.org, Alexei Starovoitov , Suren Baghdasaryan , Shakeel Butt , Johannes Weiner , Andrii Nakryiko , JP Kobryn , linux-mm@kvack.org, cgroups@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Kumar Kartikeya Dwivedi , Tejun Heo Subject: Re: [PATCH v2 00/23] mm: BPF OOM Message-ID: References: <20251027231727.472628-1-roman.gushchin@linux.dev> <87ldkonoke.fsf@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87ldkonoke.fsf@linux.dev> X-Rspamd-Server: rspam12 X-Rspam-User: X-Rspamd-Queue-Id: B136E1C000F X-Stat-Signature: fcc3zw9ah64sc6no6rpyumapugauw3pj X-HE-Tag: 1762193914-711857 X-HE-Meta: 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 00mUGvTR tuNy1J55cof0fq8W4X74eb5A71bP6Y1G0DG/JAwRJ4o7KeOvU/8cfoNJoJ6r74HorQmtGynjBKLyWsgkUjrWaBi/qTFKW2GUSf2Nw2qGpGuxkh33zfy7eyPOfJkZiR6zjJgBl0Ep87k5deZbRKmr5hEYYV+bAhcVqkmT3BkqnZ0h3EPqKEFIIOsApJZHzXBxTg8yKx/S3nXoqsQ40/+AzOE/tQp7eLubuA83D/px6tKyFIb6i1syXhFkPgdVy4VBP1Yom12MwRWrWn6Nncv1WEtydsgHhBuN+wtN1NGRipfVmhgN8fNhFcr6jZevDGEM8K+fPyp6V4CGz2btK+UpHGhvUBYujJ80ALfsiv6vu7Z7vzlDn7b6MGN3MUcR7/mOEK8gB/IwUgyWgl/3MofY65JhFC6L9CW1MyCwU X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun 02-11-25 12:53:53, Roman Gushchin wrote: > Michal Hocko 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