From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0C4ACA9EAF for ; Wed, 30 Oct 2019 06:36:16 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id B0F7520874 for ; Wed, 30 Oct 2019 06:36:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="inpJU2DW"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="RRPlrkCe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B0F7520874 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uzPl3+Xj/WmVfKprE6BLqm+Vfpjr94FDy17pkzCVzFE=; b=inpJU2DWN6hmZ4 6QmK92dKpUDAI9NgFZyIk9x6jgcnR0SE3gmLqDtGoR7K/zB5fZc1kjh7QGlkkTuQTjNK3QdmHBa2n gZYTjeREzgh7ruiVPMm0IlW8h/L9EVEUTMyv5iePktEUKigIn04pgm1xtgz2FHhuxqDQ376GAGtBc dVjqQiKV0iIjmGJYMafm9rpGEHJKEgJMN77lpj35aQhFsQJF+q9ckYWMSSHPnRmIm6UlCJjN+0JNg Tjc7obTvwVcl3u31fZtOTs3iuO8Ct2s+pTtVvDpMtFeS9pV8Wtr6LtPTpRjvrRZZ4B2551IiQdXEx 3MUtOJhTYrs/3qBc4wlw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iPhaZ-0004Ck-Jj; Wed, 30 Oct 2019 06:36:15 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iPhaX-0004CJ-5i for linux-nvme@lists.infradead.org; Wed, 30 Oct 2019 06:36:14 +0000 Received: from redsun51.ssa.fujisawa.hgst.com (unknown [199.255.47.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3475F2067D; Wed, 30 Oct 2019 06:36:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572417372; bh=ye+9uTcDFHfW4nG0kg+9QlIaQGEYdj9xh87zTZYlUwk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RRPlrkCeoOTCZI4vuUlCau2Uujy3hLqPtXwlWBgWnWsmBVeBAHhzEnP6r7GjnAVie IUItHgHHNk4Rk20C3s1Nodhd9fFIx65Z4XcurjcLU4hICUtoeX4b/uvAahdhueg/nk kZ9sHhWagswid0IcxqPMc7GaOcYrfcLQ3NdQ7N0c= Date: Wed, 30 Oct 2019 15:36:09 +0900 From: Keith Busch To: Chaitanya Kulkarni Subject: Re: [PATCH] nvmet: allow block device to use buffered I/O Message-ID: <20191030063609.GB16863@redsun51.ssa.fujisawa.hgst.com> References: <1572409583-3109-1-git-send-email-chaitanya.kulkarni@wdc.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1572409583-3109-1-git-send-email-chaitanya.kulkarni@wdc.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191029_233613_234050_1570C1C3 X-CRM114-Status: UNSURE ( 8.17 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: hch@lst.de, linux-nvme@lists.infradead.org, sagi@grimberg.me Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Oct 29, 2019 at 09:26:23PM -0700, Chaitanya Kulkarni wrote: > NVMeOF target already has a support to execute requests in the > buffered I/O mode with file backend. This patch allows=A0block devices > to be used with file backend code so that buffered I/O parameter can > be set for a block device backed namespace when newly introduce > configfs parameter use_vfs=3D1. Is the fs overhead so bad that we can't just remove the bio based nvme target? It seems low enough that having a single path to optimize is worth considering. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme