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Petersen" , Bart Van Assche , Mikulas Patocka , "linux-scsi@vger.kernel.org" Subject: Re: [RFC PATCH v2 0/2] add simple copy support Thread-Topic: [RFC PATCH v2 0/2] add simple copy support Thread-Index: AQHWyi08xMuKL73ZZUaIarInYKlQvg== Date: Tue, 8 Dec 2020 12:37:52 +0000 Message-ID: References: <20201204094659.12732-1-selvakuma.s1@samsung.com> <20201207141123.GC31159@lst.de> <01fe46ac-16a5-d4db-f23d-07a03d3935f3@suse.de> <20201207192453.vc6clbdhz73hzs7l@mpHalley> <20201208122248.utv7pqthmmn6uwv6@mpHalley> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: javigon.com; dkim=none (message not signed) header.d=none;javigon.com; dmarc=none action=none header.from=wdc.com; x-originating-ip: [129.253.240.72] x-ms-publictraffictype: Email x-ms-office365-filtering-ht: Tenant x-ms-office365-filtering-correlation-id: 50276e26-5770-4e9d-ebe9-08d89b76146e x-ms-traffictypediagnostic: SN6PR04MB4688: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: wdcipoutbound: EOP-TRUE x-ms-oob-tlc-oobclassifiers: OLM:7691; x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 83MaK3bxef/YyUz965MJhh0VWCUK1FzEM8xQPMAlBV/PCnpTj4QsfTwxmr/opNxxz7sezpcT0FuFEXE6+fthlJEolJkPnsWmn1IZey+Xm4odGv/RII+Hm6NgpXJbhNM3ZQwkMJcUFz7KV0gkjUMPhwbvjXla521O0krLnuEcJLcOfv6TleG79Rr/Br99TPv0a9i2JlseJNjwFjYhiRNG3ymLLXUHO/gJjSY/cC40C1bDaqNAJdTgFxUvGvbqmJmU7UeBv/OLzF/gKOA63vWYICchEOYXexj0cjxNyH0j88OD+2I4o9N80tC8l4SMd1Ge x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SN4PR0401MB3598.namprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(366004)(186003)(6506007)(53546011)(5660300002)(66556008)(7416002)(54906003)(4326008)(26005)(86362001)(8936002)(66446008)(91956017)(66946007)(66476007)(64756008)(71200400001)(76116006)(7696005)(2906002)(83380400001)(498600001)(52536014)(6916009)(8676002)(9686003)(55016002)(33656002)(4744005);DIR:OUT;SFP:1102; x-ms-exchange-antispam-messagedata: =?iso-8859-1?Q?hXoZZYOsSI1tef74rXtmZ/sr9UvCdM+iSb12WHZ/HirFhds/JrG+gVQp8K?= =?iso-8859-1?Q?1glI/qRMoGZ3b2bmWC0GK5xDOGeXnuzNPPfOYwSV5SlwvR0et7XbFSz1h0?= =?iso-8859-1?Q?DBqFl6xfVEVu7b8UB4iwNJY3XFJSbYJphjSTZwP41zAs2TGGEwtCmz+1BY?= =?iso-8859-1?Q?qrXEWlzC4hPpo3DvOO2IsqJpxSmdMoQxXDVekS4Vp72pAn+cNkyY3wB5sl?= =?iso-8859-1?Q?X0AWusHi4rqC0oicsH/ulnsQ92609BZf+wd5lW9VB++Ntlq5TuPgK6Xn7r?= =?iso-8859-1?Q?Jt+PZnKUY8baR33lSv54L5L2ETEZWIq53JWD/VyjasGSo3n6kfD+431QvZ?= =?iso-8859-1?Q?yjQ/sAHL5NBZ8e5Pt/5vLMK9L572MlsRsGFfIntoGgeWiLtEO02wRNPm59?= =?iso-8859-1?Q?IfkaR9sk7EbCd8Hk1YRWutH/yvbopm84LRqJjC8ksQfnAQdVlgDiFTA/H/?= =?iso-8859-1?Q?DRSRogmZRhIF1ETPpGi+D+SFuFbgWPJGU4nM2qUovkgJv7heqCC/22QI4V?= =?iso-8859-1?Q?l/C09l2QFILoQWpMQ4tH7dutI0DbrUN/6yXmTRpsbpgTThOksvIgfmsaz/?= =?iso-8859-1?Q?FTnZ8E3UU3rPFmBCT3kkXYTLFsU4iTHgOgRst8gR9mz5jj7HmmwoVNlWyc?= =?iso-8859-1?Q?yvflC6qgTZdINNHn/xZOf9h2vPYLSzq6ZHXBu1uvBWGc3QYdDHps+l0kVI?= =?iso-8859-1?Q?jczJE+zROarQdSMlmp42fwpO+DcIRMKfCXJlDNzhA1CXSMIMgM84Z/odho?= =?iso-8859-1?Q?iWzlpS4y48WUg1A7YwJSl8pY/KDzEKdHMt+pS9lSh+uGOIBKWf7VKbvqr8?= =?iso-8859-1?Q?M2Nm32qO2kqBNIxLDTJo9ANFRImB/vvb1lksDHUsu2IcdjSlRZv8vKeedc?= =?iso-8859-1?Q?yUomWavPHWpqUtmEAlPevPwTT+23dL/pDv0xV9UHAjyDIsOPzPXbb6IyYE?= =?iso-8859-1?Q?yxL1p8AGGjvMs7wIVFPU8ohUXW60YFbN/VE1Wjxd1W7vhkB0/AZj6TPOcY?= =?iso-8859-1?Q?ZPqL7ixekTYyfYd5SjZFoDaFet/MdV4i/Ddn3m?= Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: wdc.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: SN4PR0401MB3598.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 50276e26-5770-4e9d-ebe9-08d89b76146e X-MS-Exchange-CrossTenant-originalarrivaltime: 08 Dec 2020 12:37:52.3295 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: b61c8803-16f3-4c35-9b17-6f65f441df86 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: uoDEvVRI6Bu2bCZj2jMSUK1+BhUKw5uR/UrbKbu355p4YOyYZMw11ucxaAxEf80O9Li5EmBhltmcZrcpKJXmMaJJnsWdP+pAGj6XuP3FiAQ= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN6PR04MB4688 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/12/2020 13:22, Javier Gonz=E1lez wrote:=0A= > Good idea. Are you thinking of a sysfs entry to select the backend?=0A= =0A= Not sure on this one, initially I thought of a sysfs file, but then=0A= how would you do it. One "global" sysfs entry is probably a bad idea.=0A= Having one per block device to select native vs emulation maybe? And=0A= a good way to benchmark.=0A= =0A= The other idea would be a benchmark loop on boot like the raid library=0A= does.=0A= =0A= Then on the other hand, there might be workloads that run faster with =0A= the emulation and some that run faster with the hardware acceleration.=0A= =0A= I think these points are the reason the last attempts got stuck.=0A=