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 D6F61330B0B; Thu, 6 Aug 2026 05:34:10 +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=1785994453; cv=none; b=Ohz+KNb5bBvEsVwmgVctbP5WHshuRCAG8DgcxGXIzNXVLkO/PAofeHQg6HgJMvW52ygCVaUg6l94VIJK1FMt9NUlAeoK+zy+ujWiO5o6pNKfmOGVZdEDrWPBgJj6N3Fpmc1fwJOjyqs7t9Dg1x38FJvw58kwGiCoatABK5+1B7s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785994453; c=relaxed/simple; bh=qtFPb0PIesEz8aAUF8i75Bjty05zFqcGVFOo04ZMUH4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XN5HHxdYFHjUyXpRguwtcQLWrf3AlH6EXrXfyhpLX5V7V859YSDjIxotNpLlMTfmiU+sbfMuQbG7kuqc7WuuIaHX6GqHkfxxmbnv6Gc68guTf0r9N5uEao2XM8g/M0J2wB2nm65lI9pDCpBJfpzXxXvQeAq9EoOay7qojnOPN+0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ogJHBTtJ; 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="ogJHBTtJ" Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 505941F000E9; Thu, 6 Aug 2026 05:34:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785994450; bh=n9gPSN0F4S7gbGqQFG/UTpug4iTvH7g11Ov/aHjBKs4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ogJHBTtJoWZzvQTbD8nhWh0CC0f1pSL85swyRaZ0kGtyBr0E7cqcM+TZNmhPHXBB8 ZeAaCIGWRKao4LHhcgf+w0E+gPjvhzHZ1o63szJwhL0B7UO/IgeoZ9YgocnAFYUfna EiLPEedhLH6M9GzSFml27aiZVnxl/L1CvNOkYn7oCeP8ubURUh/ou+z2YENryINz0c vnduVHhvys7+r6JKvz4paP+38lmXKBvbOkh4rcjHcySCxhNynGmRpoAchrflV/r6lX N0tEPSGQPRcShLtYqnWk9c7q2WnU0ubN+KYauGOFA0VHZThVXRCfFu8nhuC/XJDVvN R/NpqCIK8swhg== Date: Wed, 5 Aug 2026 22:34:09 -0700 From: "Darrick J. Wong" To: Matthew Wilcox Cc: Amir Goldstein , John Groves , John Groves , Miklos Szeredi , Dan Williams , Bernd Schubert , Alison Schofield , John Groves , Jonathan Corbet , Jake Edge , Shuah Khan , Vishal Verma , Dave Jiang , Jan Kara , Alexander Viro , David Hildenbrand , Christian Brauner , Randy Dunlap , Jeff Layton , Jonathan Cameron , Stefan Hajnoczi , Joanne Koong , Josef Bacik , Bagas Sanjaya , Chen Linxuan , James Morse , Fuad Tabba , Sean Christopherson , Shivank Garg , Ackerley Tng , Gregory Price , Andrew Morton , Namjae Jeon , Lorenzo Stoakes , Greg Kroah-Hartman , Ira Weiny , Pasha Tatashin , Haren Myneni , Pratyush Yadav , Giovanni Cabiddu , Jiri Slaby , Ethan Nelson-Moore , Gabriel Whigham , Aravind Ramesh , Ajay Joshi , "venkataravis@micron.com" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "nvdimm@lists.linux.dev" , "linux-cxl@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "fuse-devel@lists.linux.dev" Subject: Re: [PATCH V12 00/12] famfs: the Fabric-Attached Memory File System (standalone) Message-ID: <20260806053409.GL3560084@frogsfrogsfrogs> References: <20260803022730.75731-1-john@jagalactic.com> <0100019fc572ca94-ec363dd7-3a77-484b-b4b7-f2503a0931a6-000000@email.amazonses.com> Precedence: bulk X-Mailing-List: linux-cxl@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 Thu, Aug 06, 2026 at 06:19:49AM +0100, Matthew Wilcox wrote: > On Mon, Aug 03, 2026 at 10:52:19AM +0200, Amir Goldstein wrote: > > > The most important thing to know about famfs is that it CANNOT be used as a > > > general purpose file system. It is for enabling file-based byte-level access > > > (including direct mmap) to very large (e.g. 100TB) shared/disaggregated > > > memory appliances - which have become available during this long process, > > > and which are in need of Linux support. > > > > > > So famfs cannot be used by anybody who doesn't know why they need it; Making > > > famfs standalone means it can't affect users who don't use it. And my super- > > > mega-corp employer (Micron), as well as other memory companies, need it. > > > We do not intend to abandon it, but imagine if we did: fs/famfs/ should be > > > removed if the memory companies can't be bothered to maintain it. > > > > It does not work this way. > > When vfs maintainers accept standalone famfs they accept the burden of > > maintaining it whenever vfs internal APIs change even if the filesystem was > > abandoned by the mega-corps. > > That is the code of the push back for adding new filesystems. > > Removing the fs and breaking deployed systems is not an option for the vfs > > maintainers. > > Sure it is. We removed EFS just last month, because we decided that it > wasn't worth keeping any more. Just like we removed Itanium architecture > support (and a number of other architectures before that). We've removed > other filesystems in the past (xiafs, ext, surely a few others). and freevxfs just this week because the one user/complainer said hch could let it die. --D > Yes, there are burdens on others by accepting this filesystem -- but if > it's a standalone VFS filesystem, those are felt by those who work on > the VFS. If it's part of FUSE, then it's felt by those who work on FUSE. > And we've already determined that those who work on FUSE are even more > overburdened than those who work on the VFS. > > famfs does not seem to be a natural fit for FUSE. It has needs unlike any > other Linux filesystem, and quite possibly unlike any other filesystem > that is to come. Rearchitecting FUSE to make famfs fit seems like a > very dodgy proposition to me. > >