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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2353C433FE for ; Thu, 3 Feb 2022 16:15:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345048AbiBCQPn (ORCPT ); Thu, 3 Feb 2022 11:15:43 -0500 Received: from verein.lst.de ([213.95.11.211]:38119 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231744AbiBCQPm (ORCPT ); Thu, 3 Feb 2022 11:15:42 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id 8DFEC68AFE; Thu, 3 Feb 2022 17:15:34 +0100 (CET) Date: Thu, 3 Feb 2022 17:15:34 +0100 From: Christoph Hellwig To: Luis Chamberlain Cc: Adam Manzanares , Mikulas Patocka , Javier =?iso-8859-1?Q?Gonz=E1lez?= , Chaitanya Kulkarni , "linux-block@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "dm-devel@redhat.com" , "linux-nvme@lists.infradead.org" , linux-fsdevel , Jens Axboe , "msnitzer@redhat.com >> msnitzer@redhat.com" , Bart Van Assche , "martin.petersen@oracle.com >> Martin K. Petersen" , "roland@purestorage.com" , Hannes Reinecke , "kbus @imap.gmail.com>> Keith Busch" , Christoph Hellwig , "Frederick.Knight@netapp.com" , "zach.brown@ni.com" , "osandov@fb.com" , "lsf-pc@lists.linux-foundation.org" , "djwong@kernel.org" , "josef@toxicpanda.com" , "clm@fb.com" , "dsterba@suse.com" , "tytso@mit.edu" , "jack@suse.com" , Kanchan Joshi Subject: Re: [RFC PATCH 3/3] nvme: add the "debug" host driver Message-ID: <20220203161534.GA15366@lst.de> References: <20220201102122.4okwj2gipjbvuyux@mpHalley-2> <20220202060154.GA120951@bgt-140510-bm01> <20220203160633.rdwovqoxlbr3nu5u@garbanzo> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220203160633.rdwovqoxlbr3nu5u@garbanzo> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Feb 03, 2022 at 08:06:33AM -0800, Luis Chamberlain wrote: > On Wed, Feb 02, 2022 at 06:01:13AM +0000, Adam Manzanares wrote: > > BTW I think having the target code be able to implement simple copy without > > moving data over the fabric would be a great way of showing off the command. > > Do you mean this should be implemented instead as a fabrics backend > instead because fabrics already instantiates and creates a virtual > nvme device? And so this would mean less code? It would be a lot less code. In fact I don't think we need any new code at all. Just using nvme-loop on top of null_blk or brd should be all that is needed. 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 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0E8EBC433EF for ; Thu, 3 Feb 2022 16:16:02 +0000 (UTC) Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-318-a1HLIazUPdumkKxI1S6SZA-1; Thu, 03 Feb 2022 11:15:58 -0500 X-MC-Unique: a1HLIazUPdumkKxI1S6SZA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B31D619251A2; Thu, 3 Feb 2022 16:15:53 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 84823838E6; Thu, 3 Feb 2022 16:15:53 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 044C11809CB8; Thu, 3 Feb 2022 16:15:53 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 213GFoel017892 for ; Thu, 3 Feb 2022 11:15:50 -0500 Received: by smtp.corp.redhat.com (Postfix) id BA3F42166B1A; Thu, 3 Feb 2022 16:15:50 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast04.extmail.prod.ext.rdu2.redhat.com [10.11.55.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B658C2166B18 for ; Thu, 3 Feb 2022 16:15:45 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A7DD11044560 for ; Thu, 3 Feb 2022 16:15:45 +0000 (UTC) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-158-PZ9Y-WdyN7KTVXkR9rQW_A-1; Thu, 03 Feb 2022 11:15:41 -0500 X-MC-Unique: PZ9Y-WdyN7KTVXkR9rQW_A-1 Received: by verein.lst.de (Postfix, from userid 2407) id 8DFEC68AFE; Thu, 3 Feb 2022 17:15:34 +0100 (CET) Date: Thu, 3 Feb 2022 17:15:34 +0100 From: Christoph Hellwig To: Luis Chamberlain Message-ID: <20220203161534.GA15366@lst.de> References: <20220201102122.4okwj2gipjbvuyux@mpHalley-2> <20220202060154.GA120951@bgt-140510-bm01> <20220203160633.rdwovqoxlbr3nu5u@garbanzo> MIME-Version: 1.0 In-Reply-To: <20220203160633.rdwovqoxlbr3nu5u@garbanzo> User-Agent: Mutt/1.5.17 (2007-11-01) X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-loop: dm-devel@redhat.com Cc: "djwong@kernel.org" , "linux-nvme@lists.infradead.org" , "clm@fb.com" , "dm-devel@redhat.com" , Adam Manzanares , "osandov@fb.com" , Javier =?iso-8859-1?Q?Gonz=E1lez?= , Bart Van Assche , "linux-scsi@vger.kernel.org" , Christoph Hellwig , "roland@purestorage.com" , "zach.brown@ni.com" , "dsterba@suse.com" , Chaitanya Kulkarni , "msnitzer@redhat.com >> msnitzer@redhat.com" , "josef@toxicpanda.com" , "linux-block@vger.kernel.org" , Mikulas Patocka , "kbus @imap.gmail.com>> Keith Busch" , "Frederick.Knight@netapp.com" , Jens Axboe , "tytso@mit.edu" , Kanchan Joshi , "martin.petersen@oracle.com >> Martin K. Petersen" , "jack@suse.com" , linux-fsdevel , "lsf-pc@lists.linux-foundation.org" Subject: Re: [dm-devel] [RFC PATCH 3/3] nvme: add the "debug" host driver X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Thu, Feb 03, 2022 at 08:06:33AM -0800, Luis Chamberlain wrote: > On Wed, Feb 02, 2022 at 06:01:13AM +0000, Adam Manzanares wrote: > > BTW I think having the target code be able to implement simple copy without > > moving data over the fabric would be a great way of showing off the command. > > Do you mean this should be implemented instead as a fabrics backend > instead because fabrics already instantiates and creates a virtual > nvme device? And so this would mean less code? It would be a lot less code. In fact I don't think we need any new code at all. Just using nvme-loop on top of null_blk or brd should be all that is needed. -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel