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 1F7F2C64ED6 for ; Mon, 27 Feb 2023 17:45:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229657AbjB0Rp0 (ORCPT ); Mon, 27 Feb 2023 12:45:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229754AbjB0RpZ (ORCPT ); Mon, 27 Feb 2023 12:45:25 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4A7A241E6; Mon, 27 Feb 2023 09:45:07 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A232C60EE2; Mon, 27 Feb 2023 17:44:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27632C433EF; Mon, 27 Feb 2023 17:44:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677519895; bh=/SOVKtkDSxDxmC89ievuT6HH6QX3NhvtmNmaObVIk6w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jl/ZvmRNcuW9+rhUypdYi2dd6xgmzzP8r0oObXLU2Q1eoo7mwD99uKgALcAAA4Tun Fk/PDUeywnsaN8TPspId/XjmpLG/58C0sJDU+dK7+BkkmMiyZ+i44ADEyb0jECmntA 3OoHn3Fq2GFb8E+Mn0e+rPx+MDJF/6k7RRLtUyY+K6h4IcVeHQubyAgubUUZ8of773 fd796yjYxhBxia1AV4TL0MAYDaqg0eF8A2Kxbv6f8MPpagrTAXCKiGZOqCAtJgEkFR UUFAg+ElDgXuSxAcV+n9azzcUCItmLn8lPlzcJ3iT68A68AQlcqYpg4RMxYAhihhxi bIB6CF9CB0Z+Q== Date: Mon, 27 Feb 2023 10:44:51 -0700 From: Keith Busch To: Hannes Reinecke Cc: Sagi Grimberg , Damien Le Moal , Chaitanya Kulkarni , "hch@lst.de" , "martin.petersen@oracle.com" , "dgilbert@interlog.com" , "linux-nvme@lists.infradead.org" , "linux-block@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "lsf-pc@lists.linuxfoundation.org" Subject: Re: [LSF/MM/BPF BOF] Userspace command abouts Message-ID: References: <57d8dff9-2fdb-8198-6cdc-7265797a704a@interlog.com> <23526cf9-d912-59a7-4742-6003d6ccfd45@grimberg.me> <561afa67-04d0-c675-6bbb-048313da152b@grimberg.me> <73b4dd39-9ce8-9b55-8a1d-06865f3bde32@nvidia.com> <0fe59301-65e6-d8a9-033e-0243ad59c56b@opensource.wdc.com> <316431ed-1727-7e80-2090-84ac5b334f74@grimberg.me> <3ea301b1-c808-ce08-8ec8-3a631b385fb9@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3ea301b1-c808-ce08-8ec8-3a631b385fb9@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Feb 27, 2023 at 06:28:41PM +0100, Hannes Reinecke wrote: > On 2/27/23 17:33, Sagi Grimberg wrote: > > > > I'm not up to speed on how CDL is defined, but I'm unclear how CDL at > > the queue level would cause the host to open more queues? Because each CDL class would need its own submission queue in that scheme. They can all share a single completion queue, so this scheme doesn't necassarily increase the number of interrupt vectors. > > Another question, does CDL have any relationship with NVMe "Time Limited > > Error Recovery"? where the host can set a feature for timeout and > > indicate if the controller should respect it per command? > > > > While this is not a full-blown every queue/command has its own timeout, > > it could address the original use-case given by Hannes. And it's already > > there. > I guess that is the NVMe version of CDLs; can you give me a reference for > it? They're not the same. TLER starts timing after a command experiences a recoverable error, where CDL is an end-to-end timing for all commands.