From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F593C433ED for ; Mon, 26 Apr 2021 12:03:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5250461178 for ; Mon, 26 Apr 2021 12:03:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232953AbhDZMEg (ORCPT ); Mon, 26 Apr 2021 08:04:36 -0400 Received: from mail-eopbgr750055.outbound.protection.outlook.com ([40.107.75.55]:47421 "EHLO NAM02-BL2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S231550AbhDZMEe (ORCPT ); Mon, 26 Apr 2021 08:04:34 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=RGOvqT1jb3BtPL0pMqHTmG5qUeSYT4tpiLffCWR+3L05wsAGq0chs2M4vAkt3lMsVX86RMoqUu97wZ0Y59HpOT+m0PVRtc7+MoAJA5NTqQ/o33SOS7FwVkZ7lXpeUwUs5y1lgYOVOZgQsYpSQA5e55gOT/ss1badHrXHsRcrfwbI057Rm0citHsEHF4eCQnqjIHmYPvCf84nC2mgSHOTcFKL/1347DWfbZ0qVz1dQwQWZda5J9XT9Urn7zwoFJ9nuA/bn0PuIVyuwj7z92v2qEGmRRy1PODH4Uwp2g/dSBIDdoWrD6fZSISUDsZD4eUI8myQS9ZHoDErOC67IQuCwA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=+cMw7vx3m5F5O42yb+JP2z1WjGdP8QG9pnOByvesn5Y=; b=IKVVWmfsJ7nYXPZuLEHFso20A2cLyIky4HSGLg1o4UjGBD/ANMIrdrxRv4jBvrZTN0W3SUKA8tqECcVA5Dqlk8zLQiTkq84vl7bF1et9hY1JWX+oWB19E4bZM8hAgNmqPisEnsVF1FKUuNLqWivCXbNWz6TBHwqODkIA/k3knNReM8vrS5oZFpsBQIVt9J30cicEatLdazUDKUThMqo1e2AmeYgDD2jsHGGJyrFvHW1Gn5I/jtEY/BI3Mh+78q5ntdVyg7VsT59TKCvOcngzAX00vJMnOFSsD9z/mPxtEtpJUVcyQyAwIeNaPHGl2NouYyk1FcfNsC3oBM6zeoDMKw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=+cMw7vx3m5F5O42yb+JP2z1WjGdP8QG9pnOByvesn5Y=; b=W6rriQLRix/a2G32hQhavT+Lpaz/KVGfwtcM89i94JhX6KSnBAIOUpBv98zO9/dzy+vbLRDNs22bXCo0gLLNZWci1xneHrtx5ocSfj4eiYGLCgBSh+Nw1IVzuGJqqcPdW5e15lsX/HxRYneVD1fDrtfYkLFZCdbEY3XIhNtB8/c2vruhRoh/B9hT9TE5KVnF0pHy+evDZsuRHYmDXVaDR/BBBFXwcwGlaszdJomHFy2i2UKRRArPPV13jpreyfLpniUJldIDonXOkE3q12f91a5Zgc72B5FikYhmbyn2hJqRRF9ISibxQ8RdjldUiSy/yEpN3xDwO5XU7PSIHJt8WA== Authentication-Results: kernel.org; dkim=none (message not signed) header.d=none;kernel.org; dmarc=none action=none header.from=nvidia.com; Received: from DM6PR12MB3834.namprd12.prod.outlook.com (2603:10b6:5:14a::12) by DM6PR12MB4943.namprd12.prod.outlook.com (2603:10b6:5:1bc::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4065.23; Mon, 26 Apr 2021 12:03:51 +0000 Received: from DM6PR12MB3834.namprd12.prod.outlook.com ([fe80::1c62:7fa3:617b:ab87]) by DM6PR12MB3834.namprd12.prod.outlook.com ([fe80::1c62:7fa3:617b:ab87%6]) with mapi id 15.20.4065.026; Mon, 26 Apr 2021 12:03:51 +0000 Date: Mon, 26 Apr 2021 09:03:49 -0300 From: Jason Gunthorpe To: Leon Romanovsky Cc: Doug Ledford , Shay Drory , linux-rdma@vger.kernel.org Subject: Re: [PATCH rdma-next] RDMA/restrack: Delay QP deletion till all users are gone Message-ID: <20210426120349.GP1370958@nvidia.com> References: <20210420123950.GA2138447@nvidia.com> <20210420152541.GC1370958@nvidia.com> <20210422142939.GA2407382@nvidia.com> <20210425130857.GN1370958@nvidia.com> <20210425172254.GO1370958@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Originating-IP: [47.55.113.94] X-ClientProxiedBy: BL1PR13CA0378.namprd13.prod.outlook.com (2603:10b6:208:2c0::23) To DM6PR12MB3834.namprd12.prod.outlook.com (2603:10b6:5:14a::12) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from mlx.ziepe.ca (47.55.113.94) by BL1PR13CA0378.namprd13.prod.outlook.com (2603:10b6:208:2c0::23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4087.17 via Frontend Transport; Mon, 26 Apr 2021 12:03:50 +0000 Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1lazxt-00D10C-5w; Mon, 26 Apr 2021 09:03:49 -0300 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 3ece569b-abfc-4fee-363f-08d908ab5aa8 X-MS-TrafficTypeDiagnostic: DM6PR12MB4943: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:7219; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM6PR12MB3834.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(396003)(39860400002)(366004)(136003)(346002)(376002)(1076003)(5660300002)(2906002)(2616005)(38100700002)(33656002)(316002)(66476007)(66556008)(66946007)(26005)(54906003)(426003)(186003)(4326008)(83380400001)(36756003)(9786002)(6916009)(86362001)(9746002)(8936002)(8676002)(478600001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?eknoJn3GVCV+LWG0glwWXSQzU0D4b/zX9gYEgaieppGrXt25ODRTmUWvX7af?= =?us-ascii?Q?91KJUGpZcE/u6G21Od7BrFtUTr0yoFFRJHll5CUjAbJiwtgVbRF9WZG9LMEp?= =?us-ascii?Q?4bul4YZZE2Z1pbyID0dLnGa2mPgi2Ptzn/1No3FPSvMl+0ujIfV5+K5Cp+gu?= =?us-ascii?Q?g+ZxE99K7nzRKsTeCbfHT2/1+qisQxWJn5wgpI6zmQI6KL3peLp6nFQ/Z8bV?= =?us-ascii?Q?okpviQ5hxLT5MJ1kyP45pzK6T7z9eahYtnxfabmvH70jaVakBjzTZQjafkkk?= =?us-ascii?Q?v+WRHsUrnU6Fim3UDkPvgcd7x5X0eXJO+bekJyYTsrC6kDMOBncJkK3dNNSj?= =?us-ascii?Q?7hc0UxqtEV4qFq7JImu7i0ajgipz5k8RiM7PqS2IOMM+ri8V3APw0z8RNXPi?= =?us-ascii?Q?ltI4P4rh4cm3c+nbQUMWfLsbJLjSQrZrEyT57eDIXSG7iiEOstFxos+dPKmU?= =?us-ascii?Q?K0tBNQWmini4n4vevMmRbXpzYUocjwWHW2hWhjaoI6OVxFNnDRVVfGiDiCf0?= =?us-ascii?Q?eQpVQlFRxMkCUnt1Pw0oA6s8ZysuVo/u2nh//TVMW2Fe9WCEGxiPhRg8gN5a?= =?us-ascii?Q?gBUD1nKlHenHA9MApCFEU0PRwYsJ6QM4CFh0CLjf2loeIEgQQnT9i1KLufNm?= =?us-ascii?Q?ofcXEuFWV1KXa/CSYqKaA6jI88uaWPClDx92tYROVjQXLWu7kfQqimIGkonu?= =?us-ascii?Q?0QfXockErS2vN7C9PndGLH3TeGP9Gqqx8sjcENBtfmuFaV4oA4d+1ukXPMhV?= =?us-ascii?Q?r9kr9wqD1XlTyOCUYzinTSVTBvQrLsZZd1n4+mXeOhFMtc2DBvNE/e0ut/Wo?= =?us-ascii?Q?KLP0oEbTAPa9XWdS399oPDqO68XzNVQfA5UfCTXe401mVYeuX1aeklfjdwnY?= =?us-ascii?Q?aCuru2GJbrxixV8QtlnJsIjeLJn01tRFWwGBRTjn9MwBlWp5CLbRoqeg0mMp?= =?us-ascii?Q?1mpLOd+p74/UoEwjuIaXPzMyyhnJ09tG5JRs6JBoA9MyJOe7g8x5af53mPGW?= =?us-ascii?Q?B1PEt9Z+KupBVkTOHZy5wrgwKuyG0vOZhv5IYQyhmzWLC00uNF/tdD3xaa1H?= =?us-ascii?Q?7U5qhTLbuQdW1PJ0ZNrE9dDoAZU44qYv9PVdstxTVduo8ymXaQ3YgXeriH7l?= =?us-ascii?Q?ShEQOeYdY4Xj1EBt411ICx/jrtaXqOEwmu2VPXjD9jyTUKX4mnsACRDTCLSO?= =?us-ascii?Q?hMEEj8pqUP2fJBpkng/5ktZ4YWuod703/Ia08fXw6eUyJEs4HmMo64PYElgW?= =?us-ascii?Q?+rnjGjuamRCfEEZHuMaSeJJxco4k82Gn/RU5G4aoMe4isvgNpMYr7mSXZlR9?= =?us-ascii?Q?DKfoAkOSgOIUscX7YsMAMsod?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3ece569b-abfc-4fee-363f-08d908ab5aa8 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB3834.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Apr 2021 12:03:50.9495 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: /cKTofMJoHRn6Nrs4PZFEeCadeJAdu7IuDwVBUYsCeISv7UK2PFzNqbbWBHFyo6K X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4943 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Sun, Apr 25, 2021 at 08:38:57PM +0300, Leon Romanovsky wrote: > On Sun, Apr 25, 2021 at 02:22:54PM -0300, Jason Gunthorpe wrote: > > On Sun, Apr 25, 2021 at 04:44:55PM +0300, Leon Romanovsky wrote: > > > > > The proposed prepare/abort/finish flow is much harder to implement correctly. > > > > > Let's take as an example ib_destroy_qp_user(), we called to rdma_rw_cleanup_mrs(), > > > > > but didn't restore them after .destroy_qp() failure. > > > > > > > > I think it is a bug we call rdma_rw code in a a user path. > > > > > > It was an example of a flow that wasn't restored properly. > > > The same goes for ib_dealloc_pd_user(), release of __internal_mr. > > > > > > Of course, these flows shouldn't fail because of being kernel flows, but it is not clear > > > from the code. > > > > Well, exactly, user flows are not allowed to do extra stuff before > > calling the driver destroy > > > > So the arrangement I gave is reasonable and make sense, it is > > certainly better than the hodge podge of ordering that we have today > > I thought about simpler solution - move rdma_restrack_del() before .destroy() > callbacks together with attempt to readd res object if destroy fails. Is isn't simpler, now add can fail and can't be recovered Jason