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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 E3211C10F0E for ; Thu, 18 Apr 2019 12:53:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD0602183E for ; Thu, 18 Apr 2019 12:53:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388533AbfDRMxN (ORCPT ); Thu, 18 Apr 2019 08:53:13 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:38030 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733205AbfDRMxM (ORCPT ); Thu, 18 Apr 2019 08:53:12 -0400 Received: from [123.118.215.169] (helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1hH6XL-0008Mq-GR; Thu, 18 Apr 2019 12:53:08 +0000 Subject: Re: [PATCH] nvme: determine the number of IO queues To: Minwoo Im , Maxim Levitsky , linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, keith.busch@intel.com, axboe@fb.com References: <1555510379-20199-1-git-send-email-aaron.ma@canonical.com> <096935354b16662eb481aeda1f48001ba489463c.camel@redhat.com> <99ab1942-9c38-695d-03dc-ea6eecb31217@gmail.com> From: Aaron Ma Openpgp: preference=signencrypt Autocrypt: addr=aaron.ma@canonical.com; prefer-encrypt=mutual; keydata= mQENBFffeLkBCACi4eE4dPsgWN6B9UDOVcAvb5QgU/hRG6yS0I1lGKQv4KA+bke0c5g8clbO 9gIlIl2bityfA9NzBsDik4Iei3AxMbFyxv9keMwcOFQBIOZF0P3f05qjxftF8P+yp9QTV4hp BkFzsXzWRgXN3r8hU8wqZybepF4B1C83sm2kQ5A5N0AUGbZli9i2G+/VscG9sWfLy8T7f4YW MjmlijCjoV6k29vsmTWQPZ7EApNpvR5BnZQPmQWzkkr0lNXlsKcyLgefQtlwg6drK4fe4wz0 ouBIHJEiXE1LWK1hUzkCUASra4WRwKk1Mv/NLLE/aJRqEvF2ukt3uVuM77RWfl7/H/v5ABEB AAG0IUFhcm9uIE1hIDxhYXJvbi5tYUBjYW5vbmljYWwuY29tPokBNwQTAQgAIQUCV994uQIb AwULCQgHAgYVCAkKCwIEFgIDAQIeAQIXgAAKCRDNxCzQfVU6ntJ9B/9aVy0+RkLqF9QpLmw+ LAf1m3Fd+4ZarPTerqDqkLla3ekYhbrEtlI1mYuB5f+gtrIjmcW27gacHdslKB9YwaL8B4ZB GJKhcrntLg4YPzYUnXZkHHTv1hMw7fBYw82cBT+EbG0Djh6Po6Ihqyr3auHhfFcp1PZH4Mtq 6hN5KaDZzF/go+tRF5e4bn61Nhdue7mrhFSlfkzLG2ehHWmRV+S91ksH81YDFnazK0sRINBx V1S8ts3WJ2f1AbgmnDlbK3c/AfI5YxnIHn/x2ZdXj1P/wn7DgZHmpMy5DMuk0gN34NLUPLA/ cHeKoBAF8emugljiKecKBpMTLe8FrVOxbkrauQENBFffeLkBCACweKP3Wx+gK81+rOUpuQ00 sCyKzdtMuXXJ7oL4GzYHbLfJq+F+UHpQbytVGTn3R5+Y61v41g2zTYZooaC+Hs1+ixf+buG2 +2LZjPSELWPNzH9lsKNlCcEvu1XhyyHkBDbnFFHWlUlql3nSXMo//dOTG/XGKaEaZUxjCLUC 8ehLc16DJDvdXsPwWhHrCH/4k92F6qQ14QigBMsl75jDTDJMEYgRYEBT1D/bwxdIeoN1BfIG mYgf059RrWax4SMiJtVDSUuDOpdwoEcZ0FWesRfbFrM+k/XKiIbjMZSvLunA4FIsOdWYOob4 Hh0rsm1G+fBLYtT+bE26OWpQ/lSn4TdhABEBAAGJAR8EGAEIAAkFAlffeLkCGwwACgkQzcQs 0H1VOp6p5Af/ap5EVuP1AhFdPD3pXLNrUUt72W3cuAOjXyss43qFC2YRjGfktrizsDjQU46g VKoD6EW9XUPgvYM+k8BJEoXDLhHWnCnMKlbHP3OImxzLRhF4kdlnLicz1zKRcessQatRpJgG NIiD+eFyh0CZcWBO1BB5rWikjO/idicHao2stFdaBmIeXvhT9Xp6XNFEmzOmfHps+kKpWshY 9LDAU0ERBNsW4bekOCa/QxfqcbZYRjrVQvya0EhrPhq0bBpzkIL/7QSBMcdv6IajTlHnLARF nAIofCEKeEl7+ksiRapL5Nykcbt4dldE3sQWxIybC94SZ4inENKw6I8RNpigWm0R5w== Message-ID: <130f490e-e173-750d-994e-c00f7c0da080@canonical.com> Date: Thu, 18 Apr 2019 20:52:58 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <99ab1942-9c38-695d-03dc-ea6eecb31217@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/18/19 8:13 PM, Minwoo Im wrote: >> Yes the IO queues number is 0's based, but driver would return error and >> remove the nvme device as dead. > > IMHO, if a controller indicates an error with this set_feature command, > then > we need to figure out why the controller was returning the error to host. > > If you really want to use at least a single queue to see an alive I/O > queue, > controller should not return the error because as you mentioned above, > NCQA, NSQA will be returned as 0-based.  If an error is there, that could > mean that controller may not able to provide even a single queue for I/O. I was thinking about try to set 1 I/O queue in driver to try to probe NVME device. If it works, at least system can bootup to debug instead of just remove NVME device and kernel boot hang at loading rootfs. If you still concern this 1 I/O queue I can still set it as *count = 0; At least we try all count, NVME device still failed to respond. Regards, Aaron > > Thanks, > Minwoo Im