From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 CF12E250F5 for ; Mon, 18 Sep 2023 17:12:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=PSu733GoRVslMPSzrldgnW4DQMtvUqIFfdE6Ea7KZtw=; b=QqaOJE1v345bmLMIpNweBLn/oH 6f2sZbZH4foXRRJpd1Zf7LnAzLpRH/IzhInYD+6NtcYsrz1QzAItN0ai8Kp/WQxNg/WWUgr42msSB VgtN+BZ7yUpY2eg1lxZA/nLvmd/nq3863BAiukLuaooCsrOhZcYC3P3oeJcJmHCWu6Mcj06TEwquV UNGOtgGoI2pNpX/b+fGYXjsL7Mr9yU/X2lwBARt0Me3S1gSS+eW8JyBpNt5/PWSJDeq5trmO1oJoI TMe0klFsS09bnRvKTgLllar6aE1dZDo86LPFK7KFPn6VyukqQ7xQnqXknbPM7FAOqLosyUF/yUgEo 7vqUojPw==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1qiHn2-00Fxbi-2x; Mon, 18 Sep 2023 17:12:04 +0000 Date: Mon, 18 Sep 2023 10:12:04 -0700 From: Luis Chamberlain To: Matthew Wilcox Cc: hch@infradead.org, djwong@kernel.org, dchinner@redhat.com, kbusch@kernel.org, sagi@grimberg.me, axboe@fb.com, brauner@kernel.org, hare@suse.de, ritesh.list@gmail.com, rgoldwyn@suse.com, jack@suse.cz, ziy@nvidia.com, ryan.roberts@arm.com, patches@lists.linux.dev, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, p.raghav@samsung.com, da.gomez@samsung.com, dan.helmick@samsung.com Subject: Re: [RFC v2 00/10] bdev: LBS devices support to coexist with buffer-heads Message-ID: References: <20230915213254.2724586-1-mcgrof@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Luis Chamberlain On Fri, Sep 15, 2023 at 10:51:12PM +0100, Matthew Wilcox wrote: > On Fri, Sep 15, 2023 at 02:32:44PM -0700, Luis Chamberlain wrote: > > However, an issue is that disabling CONFIG_BUFFER_HEAD in practice is not viable > > for many Linux distributions since it also means disabling support for most > > filesystems other than btrfs and XFS. So we either support larger order folios > > on buffer-heads, or we draw up a solution to enable co-existence. Since at LSFMM > > 2023 it was decided we would not support larger order folios on buffer-heads, > > Um, I didn't agree to that. Coverage on sunsetting buffer-heads talk by LWN: https://lwn.net/Articles/931809/ "the apparent conclusion from the session: the buffer-head layer will be converted to use folios internally while minimizing changes visible to the filesystems using it. Only single-page folios will be used within this new buffer-head layer. Any other desires, he said, can be addressed later after this problem has been solved." And so I think we're at the later part of this. I'm happy to see efforts for buffer-heads support with large order folio support, and so at this point I think it would be wise to look for commonalities and colalborate on what things could / should be shared. Luis