From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932260AbdA3QbW (ORCPT ); Mon, 30 Jan 2017 11:31:22 -0500 Received: from mail-by2nam01on0078.outbound.protection.outlook.com ([104.47.34.78]:65504 "EHLO NAM01-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750745AbdA3QbJ (ORCPT ); Mon, 30 Jan 2017 11:31:09 -0500 Authentication-Results: spf=pass (sender IP is 74.221.232.54) smtp.mailfrom=sandisk.com; broadcom.com; dkim=none (message not signed) header.d=none;broadcom.com; dmarc=bestguesspass action=none header.from=sandisk.com; X-AuditID: ac1c2133-0c3ff70000013ebf-51-588fe4c3afd8 From: Bart Van Assche To: "osandov@osandov.com" , "kashyap.desai@broadcom.com" , "axboe@kernel.dk" CC: "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "hch@infradead.org" , "linux-block@vger.kernel.org" , "paolo.valente@linaro.org" Subject: Re: Device or HBA level QD throttling creates randomness in sequetial workload Thread-Topic: Device or HBA level QD throttling creates randomness in sequetial workload Thread-Index: AQHSexY9XwBA1ANkAkGS0SavtM5A5g== Date: Mon, 30 Jan 2017 16:30:59 +0000 Message-ID: <1485793840.2712.1.camel@sandisk.com> References: <2d656e9c9fbde7206e40a635c61a6084@mail.gmail.com> <298b6ff6-9feb-4b70-ec4c-d1295a0e1f41@kernel.dk> 7a9b012d8c7c456e9ec87d1ba5866a9d@mail.gmail.com In-Reply-To: Accept-Language: nl-NL, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.28.1.254] Content-Type: text/plain; charset="iso-8859-1" Content-ID: MIME-Version: 1.0 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrKIsWRmVeSWpSXmKPExsWyRobxn+6xJ/0RBr+mSVmsvtvPZnF6wiIm iwPzz7Fa7L2lbXF51xw2i+7rO9gs9hw5w2jx6s9eJgcOj1n3z7J5bF6h5XH5bKnHnWt72Dzm /DnI7PF5k1wAWxSXTUpqTmZZapG+XQJXxuOnC9gLVrNVfDv3iK2B8SpLFyMnh4SAicSiFy9Y uxi5OIQEljBJHLnYAOVcYpTYt3AlK0gVm4CRxOwJe1hAEiICExklHnxdxwjiMAssZJI4s3op 2CxhgUiJ9q7vbCC2iECUxNm/s4G6OYBsPYkTOxVAwiwCqhKbJq0AK+cVMJTo3v2RGWLbDUaJ yfN2g23jFLCTWPZ9LTtIL6OArETLa26QMLOAuMStJ/OZIM4WkFiy5zwzhC0q8fLxP1YIW0Hi 84p/bBD1ehI3pk6Bsq0kHnRvY4GwtSWWLXzNDHGDoMTJmU9YJjCKzUKyYhaS9llI2mchaZ+F pH0BI+sqRrHixOTi3PTUAkMTveLEvJTM4my95PzcTYzgyFU03sH4b4P7IUYBDkYlHt4dvX0R QqyJZcWVuYcYJTiYlUR496T3RwjxpiRWVqUW5ccXleakFh9ilOZgURLnfX2sK0JIID2xJDU7 NbUgtQgmy8TBKdXAuP2JRsL7ZXne8Wtrpz7bV3tr35oTGsm5tvree/6w7zj5x/H4q7B1dvwR qfVcP5ML7/lcqY9beOVC8ZvfvvX/tu1bLW7HuHdClK3d16gtiz/M07mZvUOm/YKWct3U0zwX EkydMgWnPfHr7O1XbTDy/Le3KrpxyT9nxZtvVNTy9YWmmye28O5YoMRSnJFoqMVcVJwIAHfN vgTYAgAA X-EOPAttributedMessage: 0 X-MS-Office365-Filtering-HT: Tenant X-Forefront-Antispam-Report: CIP:74.221.232.54;IPV:NLI;CTRY:US;EFV:NLI;SFV:NSPM;SFS:(10009020)(6009001)(7916002)(39840400002)(39450400003)(39850400002)(39860400002)(39410400002)(2980300002)(438002)(24454002)(377424004)(199003)(189002)(2900100001)(81166006)(50466002)(3846002)(229853002)(50986999)(76176999)(54356999)(81156014)(6116002)(102836003)(68736007)(38730400001)(8676002)(36756003)(86362001)(626004)(93886004)(4326007)(54906002)(2270400002)(69596002)(33646002)(2906002)(97736004)(53936002)(5001770100001)(2950100002)(5660300001)(7736002)(8936002)(356003)(103116003)(23756003)(92566002)(47776003)(305945005)(106116001)(8746002)(2201001)(189998001)(106466001)(2501003)(7099028);DIR:OUT;SFP:1101;SCL:1;SRVR:BY2PR02MB1282;H:sacsmgep14.sandisk.com;FPR:;SPF:Pass;PTR:InfoDomainNonexistent;A:1;MX:1;LANG:en; X-Microsoft-Exchange-Diagnostics: 1;BL2FFO11FD044;1: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 X-MS-Office365-Filtering-Correlation-Id: 8862f348-4312-421d-82cd-08d4492d6347 X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001)(8251501002);SRVR:BY2PR02MB1282; X-Microsoft-Exchange-Diagnostics: 1;BY2PR02MB1282;3:st2nmWECecwXbO6GLItr/J/jGZUJwg4+dIm/ZAPk7AR2WJwAwZAR9Fuo+8BPUfX7G7Z11/5ZFFNgjT6vMTID3sosNb3eAq76euQHMJQiF1+N7TgsLmdwFzg5lCBrLs8DzCy8Lp0xwKx355fNWmXllouPYnNUFFDRP+Pfy73U5izleq6vX9cXCoe353APi46jOiHn3DTC0OPt4GDUP8fY56Myf1P5EBxq+sa4pmFMmXl3X9S6KjkEdHQT+2MGiHbGWoFW72fe6eWzLAzzAqS4bRGhNJDZOaM4dMOc7B2O4gsTsQAO3Z6ls1weN96aR7o2FEfj8RaK9HtRVX+lZGX6vvrmMKIwIh0X0m5U+tYjbU6UV5Jh695+4gR7bDfsggcsSNi6A3Z32H00Qbxd76JhPQ== X-Microsoft-Exchange-Diagnostics: 1;BY2PR02MB1282;25: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 X-Microsoft-Exchange-Diagnostics: 1;BY2PR02MB1282;31:dA2ePlpSy5LwbN3kGCqo4b8+ATnViGs6gn4odRizxRrHK3PHPxq/m7iKbRyQWMf22NEpYzOwktXFAzNWv2GeyfQuNX/nNjr+bmgO/4v43Eg+i1NHGcosT9CFBvfxbNAHS+9vCz4HUoojHcCz/HDCIriu98TQeJ3lmtWd7eOtla5XtPAMhY84oUs/dZVzSQdk8uqIMlxZQWj02x+0pCEA/aNqcTxVdpdsQ5FXVo2i0FO89UYB57wsvQIM0EpFXsLMpqgaUATz+sj7ppmLaxDOu5691fYN9FH6tqZ3PciZ8nQ=;20: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 X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:(17755550239193); X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(6040375)(601004)(2401047)(13023025)(13017025)(13015025)(13024025)(13018025)(8121501046)(5005006)(10201501046)(3002001)(6055026)(6041248)(20161123560025)(20161123564025)(20161123562025)(20161123555025)(6072148);SRVR:BY2PR02MB1282;BCL:0;PCL:0;RULEID:;SRVR:BY2PR02MB1282; X-Microsoft-Exchange-Diagnostics: 1;BY2PR02MB1282;4: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 X-Forefront-PRVS: 0203C93D51 X-Microsoft-Exchange-Diagnostics: =?iso-8859-1?Q?1;BY2PR02MB1282;23:ego5++PWTqCa6eVRLhyqjbnutUXtGsbkVm54omo?= =?iso-8859-1?Q?LNMLcH5GDqBoenNK+WCYV6cU5VfWfH0o7k6yw5UhQn0WPm7MiUdSQWaLPI?= =?iso-8859-1?Q?coRgDsYR4nwprTnIC3Aw6hC/iX4Jxggp91ncwwZPNmlPhSH0Dw9p9RXuB8?= =?iso-8859-1?Q?TUFdSzqDdihBnpcavpUx9YD/JSVYYRtWLluVOP2+q3m7oHnpu90wiH+S6C?= =?iso-8859-1?Q?MBSTJrMYAaHK+yn1upl7R2xFbOQWRWkpg0X+7wfOwlN/ZFxxsTvSt1tG9v?= =?iso-8859-1?Q?Tr3O7lVKyfm319elyW4PQWDF7/tMeuHRQkTgCwjzVoKDBepxFsFvMulvGa?= =?iso-8859-1?Q?jaN4/NLHnRYXtpvF3yQs9zTmrQW6nv669Ws13I1rVGfvEw0YLhsOOvRdLq?= =?iso-8859-1?Q?/XNgAXkQYhUciIXrTihbUclpRwJxv4/VePjXxAsQvQytnc7E6VIjnBX9Wk?= =?iso-8859-1?Q?YfniXFejoXCYf+QncKW6/l6OcOP1exW3NSZ5HEOQ+QpgtliftBl6IRjN4F?= =?iso-8859-1?Q?CN1QZDmaWcQz9nRjpB3AQsc9huXtraS2eN+MJRjaK4Obf4DOPkUDsRUBPf?= =?iso-8859-1?Q?oA4UyBO+XIhs1TNUV6iaBsNG43AtVDrFDIyei5WIFLH4b94eHVgT9tPFJJ?= =?iso-8859-1?Q?9r72bOZBuCPHSm78/1ZDDejxcuXurvNeJSi/Ow/cBoQ46CMS5XpJkTdzr9?= =?iso-8859-1?Q?XOlErR22kSOeqvgMfUQV9cU5cqNUR5hNV8c1eGVebzGIiaAsdiNHh+SdO4?= =?iso-8859-1?Q?Jvw93a9xjqZkj9e5eXkU3isUWKG2BRvP9bEwLSZhf7/tga/3gdlGnuKomt?= =?iso-8859-1?Q?t/H/1DmT7LgOFbEMtfUgIWQU3roM/OvhGkEn6IJUMTgqonPPmybpFQEUI1?= =?iso-8859-1?Q?4SLtRzyqX72b1Vh/p7FwB1UAZv1YiaJS1JK3k/mKmksPEoVWHWTGDq5VNp?= =?iso-8859-1?Q?B8wUv5xJkoxHu1KuCvLQlhJnCpxS4aUh3XqDtQQOYeCrJIe4ELzuCZaUs4?= =?iso-8859-1?Q?1GF66pPPEInxl9TwpszJFVVPBHbpn4npRXQx481zc3CR3/c1xc2BJx7Xy9?= =?iso-8859-1?Q?rzryZsehg09FoZDdrWLoqMF2kIgMCfxJvib83JPo733RAnqiP439oXQ+x4?= =?iso-8859-1?Q?7UK3WjcHSRscbLlcOc+s8/Vjrn12B10gbx1hndJNVGfTY+HD9iaKKFNfYD?= =?iso-8859-1?Q?PBgnUaFKjJQZ6Oj3bGBh1oHUSo1ixg+8uttN9RlZpbQYKixayMV8aWNXgd?= =?iso-8859-1?Q?Ct+FlRIqrCU5BWv4fXN05NY4x26Yz2fNmjkkG0LffjrqgKAxAhiZIzs5QW?= =?iso-8859-1?Q?M3aeUAgKBrTWXkXwC1Us880d8z99rEBiVFMFUAf89hQhDhmjr8/G10qPnF?= =?iso-8859-1?Q?b73SQ6SOzfTTNjMDjE/18kkJv44YKlreDotB4JSYtFmeEWKey8+wf3bsCP?= =?iso-8859-1?Q?j9Mg9sBPUSt3rw=3D?= X-Microsoft-Exchange-Diagnostics: 1;BY2PR02MB1282;6:PM+P5h8j4aNAuI7H4lFX03UJXjkPTLs/2t6e5I/HhsPfYGB6rFRjde8cd+tac4klnv5HgULWtvux3gKSvZ7kWb52/ssgaAteH6vcxzpQYxogyTJE69jf55WW4AXcDKjlmYCkofcceGjHj9dn1L4eLDc20uTzARAX5J9cUNxd3+5GCnc/TEfZunlNP6i3soU0RXgTcgpbv9LD/1QbCJJhrpBTFYU+DwnZBTaMOIevrvXgNVirBM7PgE57CYPGRnH/7p9jGzdT5DuSC5u+RC7rn5hoVmFCvBJKrcVWvSZGc9CE7pvFG0ox4SQqvrNIOpmlxzlc8Kzgh4h4uwVCN6DjwljJkRCwifu0gP9JJI3kcm9oftUCGqPE0R8J9jA4ekWFFZGydrTFXoVPGIDu4kvbey59miJyR5ZpT0rXdePNyDZpzoCQwNRZeqOflf5yqa6Q;5:HtjHZ77NhdVyeeVVXgtxcpp9uNFdLJJAE8w5OzW3VX3qWLZdfNjMWW4fYRbbzFy2N7dHT+mykBXRN7BSttUZWLDjJMLnyIJuoCTcU0ph+94/qNwPrMEn7liBG3hpZzGNvP2DJgcPFaX4F0E+zHlo9w==;24:EfOZZYtLN+w1OwR5TrOSQ60FAUsZmDBR0ut1a1lTuOJ8NWE85vW7yS3WeQfw6RCWoKwxaUVIVCIOfxJN4yaoE5VGTSkaqZxhR01IIfM6ux4= SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-Microsoft-Exchange-Diagnostics: 1;BY2PR02MB1282;7:Vh+aDHgdoQ5ekpaHwpfU20I3nK9TrK/4w15YoSuPXClzOn/Wf2H+7ELPo2AfgycsuCwTwRH44caG0GKO6NXWGv/8aj/JYHecNbIxhzdEDUD2n9MyEY80P+Ivnjgr9BSAHURhAB4BKWAw0kKSj9VifxasNq2rHqik/uD2+HZfaeNo+MUWeBct/b9lrcgGqUwZUeeABoN9/yPFAAaj1gZFzeqfN8vrtpzMGF6sqSE3C6TC+KXrK/AO+jksgU15IarWPc2J64HxPoocRflLRrNmjGz6+AhUk6XQssuSM1V6pUfwuPY6BSGmFEvpnTsSqL16//IJs/uXv3zCekmFqxlhw4vBp4wOmJWhkveg24KHO+IgOKT3200RqodyR01E3psTr2BMHX+AHfo8H9lW0VT1ny4CkdIZOPiq8khQdfCEZDciznkWmjmFzdadJo2xETHJIS9HMTTyh7t88nv/9DaMRg== X-OriginatorOrg: sandisk.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jan 2017 16:31:04.6269 (UTC) X-MS-Exchange-CrossTenant-Id: fcd9ea9c-ae8c-460c-ab3c-3db42d7ac64d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=fcd9ea9c-ae8c-460c-ab3c-3db42d7ac64d;Ip=[74.221.232.54];Helo=[sacsmgep14.sandisk.com] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY2PR02MB1282 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v0UGVRqq018127 On Mon, 2017-01-30 at 19:22 +0530, Kashyap Desai wrote: > - if (atomic_inc_return(&instance->fw_outstanding) > > - instance->host->can_queue) { > - atomic_dec(&instance->fw_outstanding); > - return SCSI_MLQUEUE_HOST_BUSY; > - } > + if (atomic_inc_return(&instance->fw_outstanding) > safe_can_queue) { > + is_nonrot = blk_queue_nonrot(scmd->device->request_queue); > + /* For rotational device wait for sometime to get fusion command > from pool. > + * This is just to reduce proactive re-queue at mid layer which is > not > + * sending sorted IO in SCSI.MQ mode. > + */ > + if (!is_nonrot) > + udelay(100); > + } The SCSI core does not allow to sleep inside the queuecommand() callback function. Bart.