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=-5.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 6ADDAC2BA1A for ; Fri, 24 Apr 2020 07:09:37 +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 36E7620700 for ; Fri, 24 Apr 2020 07:09:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ZRy8Bod+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36E7620700 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de 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=0cjJAbEKBz9NttwIPsRfZS9YjYsdnb28fvz+Rtkk768=; b=ZRy8Bod+z/PwIt UUoJOa+CPJQzLMAwRqnhLHIvD+7A2Xcgaqbwbbx6dOrHcrcZIrGSRhIXE8Y5t0zL24APbxPL2kTLb ulu/zplM0c04xyHWHkeWcc4KIj31CCbUoeZcUBAguUA+YFLdJUDmp/XbtTtStUV6A2NNhIDMn4jii 6JFYOWOtp7e6uxi2wLzLKMwpXuQT6PsrUwehM6xC+0QelZNAvR5PlzSXM9oxCwB2fucKsCK553oC7 SDCZWYBL9qLgyEQWmWa0hxi/+NxFBcgMMjHqADCrdYGE3eASbbWajBfmBS406z5KP8isMYeiuEkgx LlhvdbgDWIQHbI6wvu1g==; 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 1jRsSt-00020J-Vx; Fri, 24 Apr 2020 07:09:35 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jRsSr-0001z8-5n for linux-nvme@lists.infradead.org; Fri, 24 Apr 2020 07:09:34 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 73FD368CEE; Fri, 24 Apr 2020 09:09:30 +0200 (CEST) Date: Fri, 24 Apr 2020 09:09:30 +0200 From: Christoph Hellwig To: Max Gurtovoy Subject: Re: [PATCH 08/17] nvme-rdma: add metadata/T10-PI support Message-ID: <20200424070930.GC24059@lst.de> References: <20200327171545.98970-1-maxg@mellanox.com> <20200327171545.98970-10-maxg@mellanox.com> <20200421122030.GI26432@lst.de> <688ec4ba-78e8-0ba3-9ee9-3c19b3e7b0c6@mellanox.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <688ec4ba-78e8-0ba3-9ee9-3c19b3e7b0c6@mellanox.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200424_000933_365737_7232D6C1 X-CRM114-Status: GOOD ( 12.21 ) 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: axboe@kernel.dk, jsmart2021@gmail.com, sagi@grimberg.me, martin.petersen@oracle.com, shlomin@mellanox.com, linux-rdma@vger.kernel.org, israelr@mellanox.com, vladimirk@mellanox.com, linux-nvme@lists.infradead.org, idanb@mellanox.com, jgg@mellanox.com, oren@mellanox.com, kbusch@kernel.org, Christoph Hellwig 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 Thu, Apr 23, 2020 at 12:22:27PM +0300, Max Gurtovoy wrote: >>> diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c >>> index e38f8f7..23cc77e 100644 >>> --- a/drivers/nvme/host/rdma.c >>> +++ b/drivers/nvme/host/rdma.c >>> @@ -67,6 +67,9 @@ struct nvme_rdma_request { >>> struct ib_cqe reg_cqe; >>> struct nvme_rdma_queue *queue; >>> struct nvme_rdma_sgl data_sgl; >>> + /* Metadata (T10-PI) support */ >>> + struct nvme_rdma_sgl *md_sgl; >>> + bool use_md; >> Do we need a use_md flag vs just using md_sgl as a boolean and/or >> using blk_integrity_rq? > > md_sgl will be used if we'll get a blk request with blk_integrity (memory = > domain). > > use_md will be responsible for wire domain. > > so instead of this bool we can check in any place (after prev commit = > changes): > > " > > if (queue->pi_support && nvme_ns_has_pi(ns)) > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 req->use_md =3D c.common.op= code =3D=3D nvme_cmd_write || > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0 c.common.opcode =3D=3D nvme_cmd_read; > > " > > And this is less readable IMO. It would obviously have to go into a little helper, but I really hate adding lots of little fields caching easily derived information. There are a few exception, for example if we really need to not touch too many cache lines. Do you have a git tree with your current code? That might be a little easier to follow than the various patches, maybe I can think of something better. >>> + if (blk_integrity_rq(rq)) { >>> + memset(req->md_sgl, 0, sizeof(struct nvme_rdma_sgl)); >> Why do we need this memset? > > just good practice we took from drivers/scsi/scsi_lib.c. > > It's not a must and I can remove it if needed and test it. I think (and please double check) that we initialize all three fields anyway, so the memset should not be needed. _______________________________________________ linux-nvme mailing list linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme