From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752294AbeBIBvk (ORCPT ); Thu, 8 Feb 2018 20:51:40 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:57900 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752100AbeBIBvj (ORCPT ); Thu, 8 Feb 2018 20:51:39 -0500 Subject: Re: [PATCH V2 0/6]nvme-pci: fixes on nvme_timeout and nvme_dev_disable To: Keith Busch , Sagi Grimberg Cc: axboe@fb.com, hch@lst.de, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org References: <1517822415-11710-1-git-send-email-jianchao.w.wang@oracle.com> <073ce416-fd26-b41a-187d-1db9210c48b0@grimberg.me> <20180208175606.GD5039@localhost.localdomain> From: "jianchao.wang" Message-ID: Date: Fri, 9 Feb 2018 09:50:58 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180208175606.GD5039@localhost.localdomain> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8799 signatures=668665 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802090019 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Keith and Sagi Many thanks for your kindly response. That's really appreciated. On 02/09/2018 01:56 AM, Keith Busch wrote: > On Thu, Feb 08, 2018 at 05:56:49PM +0200, Sagi Grimberg wrote: >> Given the discussion on this set, you plan to respin again >> for 4.16? > > With the exception of maybe patch 1, this needs more consideration than > I'd feel okay with for the 4.16 release. > Currently, one of the block is the nvme_wait_freeze in nvme_reset_work. This cause some issues when I test this patchset yesterday. As I posted on the V1 patchset mail thread: if we set NVME_REQ_CANCELLED and return BLK_EH_HANDLED as the RESETTING case, nvme_reset_work will hang forever, because no one could complete the entered requests. if we invoke nvme_reset_ctrl after modify the state machine to be able to change to RESETTING to RECONNECTING and queue reset_work, we still cannot move things forward, because the reset_work is being executed. if we use nvme_wait_freeze_timeout in nvme_reset_work, unfreeze and return if expires. But the timeout value is tricky.. And actually, one of the possible solution to fix this cleanly is blk_set_preempt_only. It is a lightweight way to gate the new bios out of generic_make_request. Looking forward your advice on this. And many thanks for your precious time on this. Sincerely Thanks Jianchao