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 650AF11CAA for ; Fri, 15 Sep 2023 22:26:40 +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=3m9qKU8v8W/6eLBMQw+/ErP3QLnjCxMnFx4HwWmgbtM=; b=P1zEiqNoOJDZW4Zn8iLOdpq/EX EwViN7q7yUXxx+FvL7jzIuz5QzhuVHuC65u2qptCQ4MNdOaeZv6FH249hBipfGjOo15yCzdzVky7X xlzza5bm3hDb0xp469qmVxQvkn3z8cAHiElgbVPTa/LyejMKKlu19ZwFoNJpdoIdXwJnCQsOVlQw+ WJNTJ2ymWbE1+IMecYh6gFMyXFeYrKDdzLlDQHjyo/soJX2vzE8oCtlYp+43W8CY48/fgagyJboDn bYfnXaPtVwD8XaYEAVQ6vDYx5M3OF5kXy2WbXGDpW7hBKtDK55lAmOxiBvOlG0goFBflvXhQcNEns z+MMY9cw==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1qhHGg-00BUBR-18; Fri, 15 Sep 2023 22:26:30 +0000 Date: Fri, 15 Sep 2023 15:26:30 -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. If block size is equal to folio size, there > are no problems supporting one buffer head per folio. In fact, we could > probably go up to 8 buffer heads per folio without any trouble (but I'm > not signing up to do that work). Patches welcomed for buffer-head larger order folio support :) But in the meantime... Luis