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Miller" , Eric Dumazet , Jakub Kicinski , Neal Cardwell , Paolo Abeni , Willem de Bruijn , Matthieu Baerts , Mat Martineau , Michal Hocko , Roman Gushchin , Shakeel Butt , Andrew Morton , Michal =?iso-8859-1?Q?Koutn=FD?= , Tejun Heo , Simon Horman , Geliang Tang , Muchun Song , Mina Almasry , Kuniyuki Iwashima , netdev@vger.kernel.org, mptcp@lists.linux.dev, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v3 net-next 12/12] net-memcg: Decouple controlled memcg from global protocol memory accounting. Message-ID: <20250813130009.GA114408@cmpxchg.org> References: <20250812175848.512446-1-kuniyu@google.com> <20250812175848.512446-13-kuniyu@google.com> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250812175848.512446-13-kuniyu@google.com> On Tue, Aug 12, 2025 at 05:58:30PM +0000, Kuniyuki Iwashima wrote: > If all workloads were guaranteed to be controlled under memcg, the issue > could be worked around by setting tcp_mem[0~2] to UINT_MAX. > > In reality, this assumption does not always hold, and processes that > belong to the root cgroup or opt out of memcg can consume memory up to > the global limit, becoming a noisy neighbour. As per the last thread, this is not a supported usecase. Opting out of memcg coverage for individual cgroups is a self-inflicted problem and misconfiguration. There is *no* memory isolation *at all* on such containers. Maybe their socket buffers is the only thing that happens to matter to *you*, but this is in no way a generic, universal, upstreamable solution. Knob or auto-detection is not the issue. Nacked-by: Johannes Weiner