From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E972E5328C2 for ; Wed, 9 Sep 2026 11:18:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788952700; cv=none; b=VBt3JLRdbfrP2wG4x9jqyaN6W4oAq3uBVEIJEhXquOGVBnK8W3C20QFBJ/LaLxCiG5/O+d0UWWeba3swoStPnvsBHBpbNcXHLbgLUmL2MxbeoWCPz7GrA8voJ3ExRQBPgxC74o9nVVYJ2Y83Ygqdqi5EG5SmZl3o0JLXmtq51ns= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788952700; c=relaxed/simple; bh=zOEjwSnsDLGfG/pdeBNOVWeruweXwfJsxl7v7zv3/yY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bGaZEdxF1TbTs8ysAPhWDCOP+u6fUnAEevPW4aN/KG7Vzmvn2M2pIuVeZ1XzgSCaMwXAkJfqLkBH3YMhkW59tbnL/wWd29T5HWgDJPmf4dY2Le2/qXfgRp2YRAKbxczF1osGfSzdJLOY+U817houG3Nn2k5/xWGauc/txdCrWhU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FYEQtAN5; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FYEQtAN5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B58591F00A3A; Wed, 9 Sep 2026 11:18:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788952691; bh=zOEjwSnsDLGfG/pdeBNOVWeruweXwfJsxl7v7zv3/yY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=FYEQtAN5KmjTi1SPWjCLNXNqio0wiGEDLX4TLQjBVpZfHG7P1KfnyXuYvshcFpa1S B88U316k4f8BizNr3hFSBOxDd8cJZr6XPwT9l9/0v3VCoc4OHM6bNxB42X0HwTPkTX Z0JhFCO2OTJ653bQH13UfQn9EEIXrjHMqV3g+ZwMLnG3vNsnOwSI2RhmpSi7bayd80 0Aj3rIGzOj7DqyKVvq9owikr+ZgBTi6Uglul2byZHt29aUPqYs5DAjbzfO1ULdk4nW BW+Z1xwRgM+Be/vH8ixBWG1Dp0FaNGtcrS+ixLXtXwzbMyOK0sBQn39/QlaVyFovYw XmfmFxwOK8ycw== Date: Wed, 9 Sep 2026 12:18:03 +0100 From: "Lorenzo Stoakes (ARM)" To: David Laight 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: References: <20260901190123.3511535-1-noren@nvidia.com> <20260909113836.6cbe8d17@pumpkin> 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: <20260909113836.6cbe8d17@pumpkin> 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. But I'm not sure if this is something we really need to worry about? > > David > > > > > -- > > Cheers, Lorenzo > > > -- Cheers, Lorenzo