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Tue, 10 Nov 2020 19:24:40 +0000 From: "Chris Mason" To: Christoph Hellwig CC: Nick Terrell , Herbert Xu , , , , , , Kernel Team , Nick Terrell , Petr Malat , Johannes Weiner , Niket Agarwal , Yann Collet , Greg Kroah-Hartman Subject: Re: [PATCH v5 1/9] lib: zstd: Add zstd compatibility wrapper Date: Tue, 10 Nov 2020 14:24:35 -0500 X-Mailer: MailMate (1.13.2r5673) Message-ID: <4ED61269-0F19-46EB-ACE3-C6D81E0A9136@fb.com> In-Reply-To: <20201110183953.GA10656@infradead.org> References: <20201103060535.8460-1-nickrterrell@gmail.com> <20201103060535.8460-2-nickrterrell@gmail.com> <20201106183846.GA28005@infradead.org> <20201110183953.GA10656@infradead.org> Content-Type: text/plain; charset="UTF-8"; format=flowed; markup=markdown Content-Transfer-Encoding: 8bit X-Originating-IP: [172.101.208.204] X-ClientProxiedBy: CH2PR05CA0049.namprd05.prod.outlook.com (2603:10b6:610:38::26) To SA0PR15MB3839.namprd15.prod.outlook.com (2603:10b6:806:83::14) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.1.196] (172.101.208.204) by CH2PR05CA0049.namprd05.prod.outlook.com (2603:10b6:610:38::26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3564.21 via Frontend Transport; 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X-MS-Exchange-AntiSpam-MessageData: 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 X-MS-Exchange-CrossTenant-Network-Message-Id: 37346c73-784a-4a6c-ebbb-08d885ae4528 X-MS-Exchange-CrossTenant-AuthSource: SA0PR15MB3839.namprd15.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Nov 2020 19:24:40.6009 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: ATvWmPIS1uKdEm4nOglBBH5ITeq4GLYdNJY0EOXxhgusFVO+HHh4F1eq/abxaDnS X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN6PR15MB2301 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-11-10_07:2020-11-10,2020-11-10 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 spamscore=0 clxscore=1015 suspectscore=0 lowpriorityscore=0 malwarescore=0 adultscore=0 phishscore=0 bulkscore=0 mlxscore=0 priorityscore=1501 impostorscore=0 mlxlogscore=974 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011100133 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 10 Nov 2020, at 13:39, Christoph Hellwig wrote: > On Mon, Nov 09, 2020 at 02:01:41PM -0500, Chris Mason wrote: >> You do consistently ask for a shim layer, but you haven???t explained >> what >> we gain by diverging from the documented and tested API of the >> upstream zstd >> project. It???s an important discussion given that we hope to >> regularly >> update the kernel side as they make improvements in zstd. > > An API that looks like every other kernel API, and doesn't cause > endless > amount of churn because someone decided they need a new API flavor of > the day. Btw, I'm not asking for a shim layer - that was the > compromise > we ended up with. > > If zstd folks can't maintain a sane code base maybe we should just > drop > this childish churning code base from the tree. I think APIs change based on the needs of the project. We do this all the time in the kernel, and we don’t think twice about updating users of the API as needed. The zstd changes look awkward and large today because it’ a long time period, but we’ve all been pretty vocal in the past about the importance of being able to advance APIs. -chris