From: Bart Van Assche <Bart.VanAssche@wdc.com>
To: "lduncan@suse.com" <lduncan@suse.com>,
        "tang.chen@huawei.com" <tang.chen@huawei.com>,
        "cleech@redhat.com" <cleech@redhat.com>,
        "axboe@kernel.dk" <axboe@kernel.dk>
CC: "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "guijianfeng@huawei.com" <guijianfeng@huawei.com>,
        "zhengchuan@huawei.com" <zhengchuan@huawei.com>
Subject: =?utf-8?B?UmU6IOetlOWkjTogW2lzY3NpXSBEZWFkbG9jayBvY2N1cnJlZCB3aGVuIG5l?=
 =?utf-8?Q?twork_is_in_error?=
Thread-Topic: =?utf-8?B?562U5aSNOiBbaXNjc2ldIERlYWRsb2NrIG9jY3VycmVkIHdoZW4gbmV0d29y?=
 =?utf-8?Q?k_is_in_error?=
Thread-Index: AdMU7px11YQAMA8RQpqjHfoYPGQQNgAIc0wAABXO1gAAKg2GAA==
Date: Tue, 15 Aug 2017 21:45:49 +0000
Message-ID: <1502833548.2259.9.camel@wdc.com>
References: <22E823DBB7698E489DC113638F7470729C17B6@DGGEMM506-MBX.china.huawei.com>
         <1502723836.2333.3.camel@wdc.com>
         <22E823DBB7698E489DC113638F7470729C1AF0@DGGEMM506-MBX.china.huawei.com>
In-Reply-To: <22E823DBB7698E489DC113638F7470729C1AF0@DGGEMM506-MBX.china.huawei.com>
Accept-Language: en-US
Content-Language: en-US
wdcipoutbound: EOP-TRUE
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: text/plain; charset="utf-8"
Content-ID: <36D7F8533B3DCA4D867F4793C40F1E86@namprd04.prod.outlook.com>
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-originalarrivaltime: 15 Aug 2017 21:45:49.7601
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: b61c8803-16f3-4c35-9b17-6f65f441df86
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR0401MB1533
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from base64 to 8bit by nfs id v7FLkfOF020019
Content-Length: 1221
Lines: 28

On Tue, 2017-08-15 at 02:16 +0000, Tangchen (UVP) wrote:
> But I'm not using mq, and I run into these two problems in a non-mq system.
> The patch you pointed out is fix for mq, so I don't think it can resolve this problem.
> 
> IIUC, mq is for SSD ?  I'm not using ssd, so mq is disabled.

Hello Tangchen,

Please post replies below the original e-mail instead of above - that is the
reply style used on all Linux-related mailing lists I know of. From
https://en.wikipedia.org/wiki/Posting_style:

A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?

Regarding your question: sorry but I quoted the wrong commit in my previous
e-mail. The commit I should have referred to is 255ee9320e5d ("scsi: Make
__scsi_remove_device go straight from BLOCKED to DEL"). That patch not only
affects scsi-mq but also the single-queue code in the SCSI core.

blk-mq/scsi-mq was introduced for SSDs but is not only intended for SSDs.
The plan is to remove the blk-sq/scsi-sq code once the blk-mq/scsi-mq code
works at least as fast as the single queue code for all supported devices.
That includes hard disks.

Bart.