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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4858bc74298sm39687472f8f.6.2026.09.09.05.27.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Sep 2026 05:27:36 -0700 (PDT) Date: Wed, 9 Sep 2026 13:27:35 +0100 From: David Laight To: "Lorenzo Stoakes (ARM)" Cc: Johannes Weiner , Zi Yan , "Vlastimil Babka (SUSE)" , Nimrod Oren , Andrew Morton , David Hildenbrand , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Hugh Dickins , Nirmoy Das , Dragos Tatulea , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] mm: remove min_free_kbytes adjustment for THP Message-ID: <20260909132735.1fc1a309@pumpkin> In-Reply-To: References: <20260901190123.3511535-1-noren@nvidia.com> <20260909113836.6cbe8d17@pumpkin> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) 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-Transfer-Encoding: 7bit On Wed, 9 Sep 2026 12:18:03 +0100 "Lorenzo Stoakes (ARM)" wrote: > On Wed, Sep 09, 2026 at 11:38:36AM +0100, David Laight wrote: > > On Wed, 9 Sep 2026 09:11:04 +0100 > > "Lorenzo Stoakes (ARM)" wrote: > > > > > On Tue, Sep 08, 2026 at 03:30:30PM -0400, Johannes Weiner wrote: > > > > On Tue, Sep 08, 2026 at 08:24:38AM -0400, Zi Yan wrote: > > > > > On Tue Sep 8, 2026 at 7:54 AM EDT, Vlastimil Babka (SUSE) wrote: > > > > > > Given neither of the patchset versions achieved universal acceptance, could > > > > > > we try just disabling all the automatic (re)calculations of min_free_kbytes > > > > > > the first moment the sysctl gets adjusted from userspace? > > > > > > > > > > Sounds good to me. Johannes, WDYT? > > > > > > > > +1 That sounds good to me as well. > > > > > > Me also! :>) > > > > You might want some method of restoring the default behaviour. > > Maybe setting to 0 can be used (if that is just silly). > > I suppose the concern would be an embedded user for some reason enabling > CONFIG_TRANSPARENT_HUGEPAGE and then defaulting to THP ->madvise and getting the > bigger reserves before somehow disabling it after boot. Or just testing whether it makes any difference to a workload. David > > But I'm not sure if this is something we really need to worry about? > > > > > David > > > > > > > > -- > > > Cheers, Lorenzo > > > > > > > -- > Cheers, Lorenzo