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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 AF323C4CEC4 for ; Wed, 18 Sep 2019 17:08:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7388E21907 for ; Wed, 18 Sep 2019 17:08:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568826490; bh=G32la0/Uj46Si9JMGEgwbmCiq3XWbFpIxwtdy37oWGg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=uLBWzKB35ibEP/KNH8zM9CRhsff9EsbGJ9zJnHbmgeZHSpqCLdjN57q0n7L2vFjYk 6H5mu4um8BahEvXjd6U8ACmnp/C+gn39RXdiFPDSpBscQKwBSnpLRzbrOr0FWZDZKH wL01QEJroVQoeYEIuRcgQ0hK+Ca+4oX1SCGTlJrU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732068AbfIRRIJ (ORCPT ); Wed, 18 Sep 2019 13:08:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:33524 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727243AbfIRRIJ (ORCPT ); Wed, 18 Sep 2019 13:08:09 -0400 Received: from C02WT3WMHTD6 (unknown [8.36.226.102]) (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 AE93520665; Wed, 18 Sep 2019 17:08:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568826489; bh=G32la0/Uj46Si9JMGEgwbmCiq3XWbFpIxwtdy37oWGg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YP2Yqo7A+koYz2c0hxGZWLyAtwlLvVGPuowlGAe8Oxuzos29a5n15XvP2WSACUtF4 pM3ZQ7G/mmiXf5s9lQ1w+w+KmvZvV997vH2ORoIeMMda7cK13y0zwAoDXs5WviUnX5 /4C893hbfXv6atKsV30Y0YVVUZ6x1CmhNQNnC2RA= Date: Wed, 18 Sep 2019 11:08:07 -0600 From: Keith Busch To: Christoph Hellwig Cc: "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: <20190918170807.GA50966@C02WT3WMHTD6> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190918132611.GA16232@lst.de> User-Agent: Mutt/1.12.1 (2019-06-15) 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 03:26:11PM +0200, Christoph Hellwig wrote: > Even if we had a use case for that the bounce buffer is just too ugly > to live. And I'm really sick and tired of Intel wasting our time for > their out of tree monster given that they haven't even tried helping > to improve the in-kernel write caching layers. Right, I don't have any stake in that out-of-tree caching either. I am more just interested in trying to get Linux to generically reach as many NVMe spec features as possible, and extended formats have been in-spec since the beginning of nvme. 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.