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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFC45C43334 for ; Tue, 21 Jun 2022 17:58:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3AC098E000F; Tue, 21 Jun 2022 13:58:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 35D448E0003; Tue, 21 Jun 2022 13:58:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2251F8E000F; Tue, 21 Jun 2022 13:58:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 105E58E0003 for ; Tue, 21 Jun 2022 13:58:52 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id DA03061017 for ; Tue, 21 Jun 2022 17:58:51 +0000 (UTC) X-FDA: 79603003662.18.61AD90F Received: from NAM04-BN8-obe.outbound.protection.outlook.com (mail-bn8nam04on2072.outbound.protection.outlook.com [40.107.100.72]) by imf27.hostedemail.com (Postfix) with ESMTP id 6A9F14001C for ; Tue, 21 Jun 2022 17:58:51 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=hgnDnMyM5wd13Qgg8+frNP5tePKNXg/zeRxzCAp67s4LPhC4PkDY5tz3RWNyJb/qep4uq0x4hN8TIDNRHrweSxj1IDjsAkyFNJzFTBL5zFfN8JORnmdV58RELZyUjcJLJNCkBy/b5CeqD86SQMrk8F0QgmS4AniEm2+lcaDgF2fb+4IY8RlqRd/3ft4Q7UtLYNj9MSYNVFg3TUOVj8Q7sTJbSf7SsQqJfQLLMWjgquK61lmmW3qWIzdBGs3ZEGdhNkP4u3y1qv6UGWN8ebQuhXqeOS//gCEpHlRl/mGxghqPrp7LOJC72lgDAGC81lSpmtrtLRyd1UaECB5zNf4HjQ== 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-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=5+6j1VTp1owv0vIT8gXCFvVOZQfO7tHnO3zb8YkWIKw=; b=TmSkQikk+PJs3I0bybVQyETTxOpp71MIlQ40jpR7r96g8y3ujGVC71Adphk8ExIUrYy4H3OdKSgP8jMuyu34epCR5HwoSFUQbGh1YjXZ/+nOo1bv/XlD+sIkFgohC98FMx/dkxm94OApva3ON2FMgaIk8ppcGTflD8tgGUbIqLkrbph6h6tmIREjwKtyL5b0OlyP8cGAXTY5ZCfWbDafy+uexoL52UBkEWCCtibjf6ain/DaGgNOAH+gVbwNGMzuCIMG0iJkESI9060GsWT4v4nGDre7ZOzARx0VsiV0wRDN2tKdO1GWOxTKG0Lz+qLlDdMbkNoUZPDU2QX1bwFmlQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=vmware.com; dmarc=pass action=none header.from=vmware.com; dkim=pass header.d=vmware.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=vmware.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=5+6j1VTp1owv0vIT8gXCFvVOZQfO7tHnO3zb8YkWIKw=; b=yNR89JjNh6/e4k9NHynSQiZDv7pckuJYhIbKlPmjy2ZbjiuvDDaYzHagcCSFVVhy9Pf+F17ZYdQT0h5KXoff9l3mP+etR2jw+SqwMAP3HKjyE6VamcTHivRqenyF3F2powR+Z5BXQS6hfSfMTESwvSq++vyIznX71t4NG/KbeOk= Received: from BY3PR05MB8531.namprd05.prod.outlook.com (2603:10b6:a03:3ce::6) by CO2PR05MB2774.namprd05.prod.outlook.com (2603:10b6:102:11::26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5373.15; Tue, 21 Jun 2022 17:58:49 +0000 Received: from BY3PR05MB8531.namprd05.prod.outlook.com ([fe80::a4f8:718a:b2a0:977f]) by BY3PR05MB8531.namprd05.prod.outlook.com ([fe80::a4f8:718a:b2a0:977f%5]) with mapi id 15.20.5373.015; Tue, 21 Jun 2022 17:58:48 +0000 From: Nadav Amit To: Peter Xu CC: Linux MM , David Hildenbrand , Mike Kravetz , Hugh Dickins , Andrew Morton , Axel Rasmussen , Mike Rapoport Subject: Re: [RFC PATCH v2 4/5] userfaultfd: zero access/write hints Thread-Topic: [RFC PATCH v2 4/5] userfaultfd: zero access/write hints Thread-Index: AQHYhHSiD6ptuxKI80qnGyCa1pMmRK1aGQ2AgAADfICAAAsZAIAAAJEA Date: Tue, 21 Jun 2022 17:58:48 +0000 Message-ID: <33013FD3-7DB1-41A0-A23F-7B4E53A60FD7@vmware.com> References: <20220619233449.181323-1-namit@vmware.com> <20220619233449.181323-5-namit@vmware.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: Apple Mail (2.3696.100.31) x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 3e8cc3f9-ccb5-4d9e-0b85-08da53afb189 x-ms-traffictypediagnostic: CO2PR05MB2774:EE_ x-microsoft-antispam-prvs: x-ms-exchange-senderadcheck: 1 x-ms-exchange-antispam-relay: 0 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:BY3PR05MB8531.namprd05.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230016)(4636009)(39860400002)(366004)(346002)(396003)(136003)(376002)(186003)(38100700002)(86362001)(83380400001)(8676002)(71200400001)(54906003)(316002)(4326008)(66946007)(64756008)(66446008)(76116006)(66476007)(66556008)(36756003)(5660300002)(6916009)(41300700001)(33656002)(2616005)(6486002)(6506007)(6512007)(53546011)(26005)(38070700005)(8936002)(122000001)(4744005)(478600001)(2906002)(45980500001);DIR:OUT;SFP:1101; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?utf-8?B?ekVkZ1p6cGIyZDJReWhZLzBQK2c3YzVkb1p0QmhNUVduMHNSRitYZ28yckNq?= =?utf-8?B?WFJWSGpwbG9iR1dqTm5BR0V5K0oxSTMrSUtLdXRkNjRMRzdDUFpLNUE1MTkv?= =?utf-8?B?YTBsNTkyRzVYNE5QNFBoeVE4WE9MeFVZUU9PaGNGanBOaURCTTV1SFZMZXd6?= =?utf-8?B?WStCYkljYmRZUytlZndmcUJBUTFWYnQ1ejBPd1JkM1piOHZlZDU1VHZMRDdJ?= =?utf-8?B?M1pXRmpnditpWjZDbGNZaFJ4YUxWWHlLUkEzMVZiNHVKem9lN2FYNXVhQ0dq?= =?utf-8?B?dE1IR2Y0K1ZISmY5RzAzVjA3YXd0dVVRM2NuYzNGR2RxRDlRejNIVzFMYVp6?= =?utf-8?B?SmNveks1a05OWHpTNldhbmpjYUVOVzVYbTRhcnR0T3A1SC9iQ1BsUjdkdlRu?= =?utf-8?B?ejVjSm4yM0dUd21uV0NUdWxucjBpaW85OW1CNG5ZT1d0QnhQSjVTcUtKMWNh?= =?utf-8?B?alhyUzJnNjNORHJnMlhWakdpeUZlVjFYL28zWFNjaTVmcEhMbThrOUJjbXpx?= =?utf-8?B?ZFMvWnMrRGt3MFdJRFFpVHZ6YU1UaWN2R0VVbzhObDcwVWM3b0FMbUV1U3hR?= =?utf-8?B?anBrQVZOeE0rSmYvYU1Ca1dmZUJSbVVVM1FNN0lRdkRxWS91ZWozTDZXcld6?= =?utf-8?B?WDZLNFVuTGhRSXh0dDBjMWc0dG4vODdaYSttMHVCRGFuSU80RHV1YmtDc3hM?= =?utf-8?B?ZmlyQTlxdHJpeWF4THlRUjZEL2NlUTJ0aEZJUXc0TkNCQ2dQRzcwamtYc3do?= =?utf-8?B?cS9JRk9EWEJNNUVDRVJndzMwV1A4SDYzQk1iWlpyL3phbCtaRmZFTTkySGp3?= =?utf-8?B?K05yV2I0KzIyYk9JSjQrTkpod0w5M1hqeUJGU2RXWGUzaklwVFEyYms4Q1Nq?= =?utf-8?B?b0w0K29tNHlWcEFBYnRhUWd1U21CK1luNlYzZHd2UExJRFJMNWV5ZmpWME9C?= =?utf-8?B?WmpudllwQ2gyRG9UdnM5R0g4aUlEelJRVFdiMTNPWXUzblVJRWhUQjJuODZI?= =?utf-8?B?bGlWT3J0bitkVFNPZnVhZXRLeldsdWgzckpMRzlmeXMvaUtqY1E5TGxONFVw?= =?utf-8?B?bE1jMGNMWituOEYxeWY0dWV2dElveTdxU3VYM3dQSmlWV2g4dm4xd1VzNUNl?= =?utf-8?B?b3lFRDhsZWFRSVlWUitJblFLMVZJTzl0dU5DaG8vRTB3ZEk5dTdOWHFHaXl5?= =?utf-8?B?U1VFaGpDdWI1c09IamFTZ2FVeWtaeGY1QngwR0hsZ1N3RmpaSml5YXJDNys5?= =?utf-8?B?RDVOaTQ5Y0Y3SUJEbWpMc1gzSEZvejVzSjZRcEkzQ2VJVHFoY05tZWNLUUNk?= =?utf-8?B?akhvR2wzZzZVVFR0UG1uaWt6bWYvQStzb0dKUUptRXdUaEY5bG8weXl0eFVJ?= =?utf-8?B?SUtLQ1gwWC9MdXlHYlViZU1Gajd2ZDY0YlUvUW5pN3VKcVozRWxyTmp0Nlls?= =?utf-8?B?ZWxFN1BzdWNXSWFyRU4rRnhPN3JSdURySFh5M1R5Qkw2MWR4RENMQ0FFaW9j?= =?utf-8?B?OHhtS3pQNi9HSW5SVzhTYlArRGpxYkZLazRJTFRkeVFkMTZzY1RTVmExV0Jy?= =?utf-8?B?Y3VGY2k1d21KTm91ZlRjbSt0czhSbDBSNm1uR1lqSXZWck5JOG1LY2VzMHY2?= =?utf-8?B?OWRaeW44TGFSaTBMMEdzd3h0ck9zUDVkVWpjc1RzdHhNNDJIcklxTFpBMFVs?= =?utf-8?B?Tk9icUNPcFB3V3VDbGFUeVZ6N2NYSHBLL1lQNG5ZY3cycHhZQXZMOHVWMlY4?= =?utf-8?B?RkNrZ1VqYlJHUGVKR2x4NE1lc0FMekxGcW5KMCtYUHpKOTdTTitOeDk3Qjl0?= =?utf-8?B?MU1UUFBRK29xZDYyWmNTZzJCbmJjV3I2ZDdDZ2lrMGgzT1Y2T0hYLzVkOStp?= =?utf-8?B?K1lzNngwaUl1Z1c1Z21NbjQrM3A4MW5LZ1ZZbEwxWnI3U2lZUWNnY05iTGdD?= =?utf-8?B?N2lWWnFRbERSWFkwR3FyTTJQTmpXTHJ2bEdGNm9iSzA3V3hwNThUZ2d1Kyty?= =?utf-8?B?YVJjQngya0VMM293VWsxdE5neTNDQ1RldmZoYUswTERvblIyWmw3YVFSNmZI?= =?utf-8?B?QXQwb2J5MXkrekFQeFZSRUxMN3BJdGJZR1FjU21DeDBsdEJPYTh1SzBSNExw?= =?utf-8?B?VnVSR003TlpFdFJXemFMYzBrSkx6Z1V3UFRuY29vWTdoRXJaajBEcW9QRWZI?= =?utf-8?B?Z2RKdFlmaHFNMndINTNaR2lGTXRqd0VtV0ZZT2N2OE5ZZ09jMHNVRm1IM1NX?= =?utf-8?B?YmtEUWkzbDF6dkp1UmM1L2dBMUhpeVhscUVGTVp2U1pCYXRZTFovVXk4SFJO?= =?utf-8?B?cGZPR3NTeG5RWDJ3YW9EVWc1ZXpPT29oQTB1WE9SejcrOEJoSDMvdz09?= Content-Type: text/plain; charset="utf-8" Content-ID: Content-Transfer-Encoding: base64 MIME-Version: 1.0 X-OriginatorOrg: vmware.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: BY3PR05MB8531.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3e8cc3f9-ccb5-4d9e-0b85-08da53afb189 X-MS-Exchange-CrossTenant-originalarrivaltime: 21 Jun 2022 17:58:48.8652 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: b39138ca-3cee-4b4a-a4d6-cd83d9dd62f0 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 8sOJ0E1hTZfULkfKSOnR/T9/d826efBLbePgPq0/pcneRMH+KT1gPvWrl6GeaNbBxx7wW3Ux4rFgsbJtXKHKIw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO2PR05MB2774 ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1655834331; a=rsa-sha256; cv=pass; b=2mKB06fQqjAb8czm2k9Dh14sqlCndU9S9eaU0buY0wWe65Hk/9gGFINUE7t9G69Zx3I4u4 9RWnPALoVlQ6w3LFfFuEcjf8hQhM8cU48sSf8c452vD/CcvWIcYVjJsBJRP++bQEtrjwPh +IeT+mPGZSRlB7WAB2gwNJi1Qafny04= ARC-Authentication-Results: i=2; imf27.hostedemail.com; dkim=pass header.d=vmware.com header.s=selector2 header.b=yNR89JjN; dmarc=pass (policy=quarantine) header.from=vmware.com; spf=none (imf27.hostedemail.com: domain of namit@vmware.com has no SPF policy when checking 40.107.100.72) smtp.mailfrom=namit@vmware.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655834331; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5+6j1VTp1owv0vIT8gXCFvVOZQfO7tHnO3zb8YkWIKw=; b=AjAoKuMzw/kpKSRQ8RXC0fLLgzd+emRw6rsyer8RCFQXx4fQyXoQ9DFAou4R20zBlgJ7b2 9SwJ20hHxIgTOjBclczXs0BOSq0XX+pAUvod5MLHjwK5mGjnzCVrJDVfEUpJR9TiZVRLaJ +tobRNIxd754i9XAooi0AJqcNpwgloc= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 6A9F14001C X-Stat-Signature: jcamo47udzss4gd9gxqg7xxduuu9zqrn X-Rspam-User: Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=vmware.com header.s=selector2 header.b=yNR89JjN; dmarc=pass (policy=quarantine) header.from=vmware.com; spf=none (imf27.hostedemail.com: domain of namit@vmware.com has no SPF policy when checking 40.107.100.72) smtp.mailfrom=namit@vmware.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") X-HE-Tag: 1655834331-285048 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: T24gSnVuIDIxLCAyMDIyLCBhdCAxMDo1NiBBTSwgUGV0ZXIgWHUgPHBldGVyeEByZWRoYXQuY29t PiB3cm90ZToNCg0KPiDimqAgRXh0ZXJuYWwgRW1haWwNCj4+PiBOaXQ6IGNhbiBkcm9wIHRoaXMg c2luY2UgcmV0IHdpbGwgYWx3YXlzIGJlIC1FTk9NRU0gaGVyZS4uDQo+PiANCj4+IEkgbm90aWNl ZC4gSnVzdCB0aG91Z2h0IGl0IGlzIGNsZWFyZXIgdGhpcyB3YXksIGFuZCBtb3JlIHJvYnVzdCBh Z2FpbnN0DQo+PiBmdXR1cmUgY2hhbmdlcy4NCj4gDQo+IEknZCByYXRoZXIgbGVhdmUgdGhhdCBm b3IgZnV0dXJlLCBidXQgaWYgeW91IHJlYWxseSBwcmVmZXIgdGhhdCBubyBwcm9ibGVtDQo+IG9u IG15IHNpZGUgdG9vLg0KPiANCj4gUGxlYXNlIGp1c3Qgc3RpbGwgY2hlY2sgWzFdIGFib3ZlIGFu ZCB0aGF0J3MgdGhlIG1ham9yIHJlYWwgY29tbWVudCwganVzdA0KPiB0byBtYWtlIHN1cmUgaXQn cyBub3Qgb3Zlcmxvb2tlZC4uDQoNClllcy4gSSBub3RpY2VkIGl0IGp1c3QgYWZ0ZXIgc2VuZGlu ZyBteSBlbWFpbCwgYW5kIGRpZG7igJl0IHdhbnQgdG8gc3BhbS4NCkZpeGVkLg0KDQpUaGFua3Mg Zm9yIG5vdGljaW5nIGl0ISENCg0KUmVnYXJkcywNCk5hZGF2