From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753216AbeBEPJb (ORCPT ); Mon, 5 Feb 2018 10:09:31 -0500 Received: from mga04.intel.com ([192.55.52.120]:21162 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752914AbeBEPJY (ORCPT ); Mon, 5 Feb 2018 10:09:24 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,465,1511856000"; d="scan'208";a="27411002" Date: Mon, 5 Feb 2018 08:13:14 -0700 From: Keith Busch To: "jianchao.wang" Cc: axboe@fb.com, linux-kernel@vger.kernel.org, hch@lst.de, linux-nvme@lists.infradead.org, sagi@grimberg.me Subject: Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case Message-ID: <20180205151314.GP24417@localhost.localdomain> References: <1517554849-7802-1-git-send-email-jianchao.w.wang@oracle.com> <1517554849-7802-3-git-send-email-jianchao.w.wang@oracle.com> <20180202182413.GH24417@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 05, 2018 at 10:26:03AM +0800, jianchao.wang wrote: > > Freezing is not just for shutdown. It's also used so > > blk_mq_update_nr_hw_queues will work if the queue count changes across > > resets. > blk_mq_update_nr_hw_queues will freeze the queue itself. Please refer to. > static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, Yes, but how many requests are you letting enter to their demise by freezing on the wrong side of the reset? We don't use the nuclear option out of convenience.