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[109.81.20.148]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-483bfb8724bsm170155795e9.11.2026.03.02.08.26.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Mar 2026 08:27:00 -0800 (PST) Date: Mon, 2 Mar 2026 17:26:59 +0100 From: Michal Hocko To: Kairui Song Cc: Yafang Shao , Barry Song <21cnbao@gmail.com>, lenohou@gmail.com, akpm@linux-foundation.org, axelrasmussen@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, weixugc@google.com, wjl.linux@gmail.com, yuanchu@google.com, yuzhao@google.com Subject: Re: [PATCH] mm/mglru: fix cgroup OOM during MGLRU state switching Message-ID: References: <20260228161008.707-1-lenohou@gmail.com> <20260228212837.59661-1-21cnbao@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 5896AA0019 X-Stat-Signature: kh16hqkt9k7z3ksbiimb5pcgpacwfrqs X-Rspam-User: X-HE-Tag: 1772468822-821587 X-HE-Meta: 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 z7cZD6hj 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon 02-03-26 16:00:03, Kairui Song wrote: > On Mon, Mar 2, 2026 at 3:43 PM Yafang Shao wrote: [...] > > > To be honest, the on/off toggle is quite odd. If possible, > > > I’d prefer not to switch MGLRU or active/inactive > > > dynamically. Once it’s set up during system boot, it > > > should remain unchanged. > > > > While it is well-suited for Android environments, it is not viable for > > Kubernetes production servers, where rebooting is highly disruptive. > > This limitation is precisely why we need to introduce dynamic toggles. > > I agree with Barry, the switch isn't supposed to be a knob to be > turned on/off frequently. Is there any actual usecase other than debugging to switch the reclaim plementation back and forth? In other words do we really need to care about this issue at all? Is the additional code worth it? -- Michal Hocko SUSE Labs