Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
To:     Daniel Wagner <dwagner@suse.de>, Hannes Reinecke <hare@suse.de>
Cc:     linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
        James Smart <james.smart@broadcom.com>,
        Keith Busch <kbusch@kernel.org>,
        Ming Lei <ming.lei@redhat.com>,
        Wen Xiong <wenxiong@us.ibm.com>,
        James Smart <jsmart2021@gmail.com>
References: <20210802112658.75875-1-dwagner@suse.de>
 <20210802112658.75875-7-dwagner@suse.de>
 <79c89923-f586-79e7-6dfd-c15ceb21f569@suse.de>
 <20210804080847.bajae2twtnmccvq7@beryllium.lan>
From:   Sagi Grimberg <sagi@grimberg.me>
Message-ID: <d43f83cf-a3cd-df16-5af8-1f530b25d1cc@grimberg.me>
Date:   Tue, 10 Aug 2021 18:05:04 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.11.0
MIME-Version: 1.0
In-Reply-To: <20210804080847.bajae2twtnmccvq7@beryllium.lan>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk


> On Wed, Aug 04, 2021 at 09:23:49AM +0200, Hannes Reinecke wrote:
>> There still is now an imbalance, as we're always calling
>> 'nvme_unfreeze()' (irrespective on the number of queues), but will only
>> call 'nvme_start_freeze()' if we have more than one queue.
>>
>> This might lead to an imbalance on the mq_freeze_depth counter.
>> Wouldn't it be better to move the call to 'nvme_start_freeze()' out of
>> the if() condition to avoid the imbalance?
> 
> What about something like nmve_is_frozen() which would avoid the tracking
> of the queue state open coded as it is right?

Why is there a conditional freeze?