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[109.81.88.11]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-486f8c292e2sm48894715e9.2.2026.03.19.01.35.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Mar 2026 01:35:40 -0700 (PDT) Date: Thu, 19 Mar 2026 09:35:38 +0100 From: Michal Hocko To: Shakeel Butt Cc: Daniil Tatianin , Andrew Morton , Johannes Weiner , Roman Gushchin , Muchun Song , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Axel Rasmussen , Yuanchu Xie , Wei Xu , Brendan Jackman , Zi Yan , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, yc-core@yandex-team.ru Subject: Re: [PATCH] mm: add memory.compact_unevictable_allowed cgroup attribute Message-ID: References: <3db237d0-1ee8-44b7-a356-f3015173f7c2@yandex-team.ru> <7ca9876c-f3fa-441c-9a21-ae0ee5523318@yandex-team.ru> <73322279-c6f8-4319-827b-938c20c96b9b@yandex-team.ru> Precedence: bulk X-Mailing-List: linux-kernel@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: On Wed 18-03-26 12:55:49, Shakeel Butt wrote: [...] > IMO we should actually deprecate compact_unevictable_allowed and always allow > compaction for unevictable memory. We should decouple the notion of mlocked > memory from the pinned/unmovable memory. Pinned memory has much more > consequences on the system related to fragmentation and availability of larger > folios than mlocked memory. If there are applications which need unmovable > memory, they should request it explicitly. I don't think there is an API for > such memory but for such use-cases, it makes sense to have an explicit API. That would be really hard to do in a backward compatible way and there are workloads (e.g. RT) where mlock is supposed to imply even no minor faults. -- Michal Hocko SUSE Labs