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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 03F43C4CEC4 for ; Wed, 18 Sep 2019 17:10:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D90D821920 for ; Wed, 18 Sep 2019 17:10:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731438AbfIRRKC (ORCPT ); Wed, 18 Sep 2019 13:10:02 -0400 Received: from verein.lst.de ([213.95.11.211]:34657 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727243AbfIRRKA (ORCPT ); Wed, 18 Sep 2019 13:10:00 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id DB71568B05; Wed, 18 Sep 2019 19:09:56 +0200 (CEST) Date: Wed, 18 Sep 2019 19:09:56 +0200 From: Christoph Hellwig To: Keith Busch Cc: Christoph Hellwig , "Baldyga, Robert" , "axboe@fb.com" , "sagi@grimberg.me" , "linux-nvme@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "Rakowski, Michal" Subject: Re: [PATCH 0/2] nvme: Add kernel API for admin command Message-ID: <20190918170956.GA19639@lst.de> References: <20190913111610.9958-1-robert.baldyga@intel.com> <20190913143709.GA8525@lst.de> <850977D77E4B5C41926C0A7E2DAC5E234F2C9C09@IRSMSX104.ger.corp.intel.com> <20190916073455.GA25515@lst.de> <850977D77E4B5C41926C0A7E2DAC5E234F2C9D03@IRSMSX104.ger.corp.intel.com> <20190917163909.GB34045@C02WT3WMHTD6.wdl.wdc.com> <20190918132611.GA16232@lst.de> <20190918170807.GA50966@C02WT3WMHTD6> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190918170807.GA50966@C02WT3WMHTD6> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 18, 2019 at 11:08:07AM -0600, Keith Busch wrote: > And yes, that bouncing is really nasty, but it's really only needed for > PRP, so maybe let's just not ignore that transfer mode and support > extended metadata iff the controller supports SGLs. We just need a > special SGL setup routine to weave the data and metadata. Well, what is the point? If people really want to use metadata they should just buy a drive supporting the separate metadata pointer. In fact I haven't had to deal with a drive that only supports interleaved metadata so far given how awkward that is to deal with. But based on the discussions here it seems Intel is stupid enough to ship such a thing.