Received: by 2002:ac0:a582:0:0:0:0:0 with SMTP id m2-v6csp786657imm; Thu, 4 Oct 2018 03:23:56 -0700 (PDT) X-Google-Smtp-Source: ACcGV63/Uk1grsraL3bMQ5TsiT6b48O2Ng7IAjtngtRyImGGmCqWaPWnC1ZszUf455pyUEPLXjm7 X-Received: by 2002:a63:3207:: with SMTP id y7-v6mr5161441pgy.101.1538648636029; Thu, 04 Oct 2018 03:23:56 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1538648635; cv=none; d=google.com; s=arc-20160816; b=Irg2TDsqYcGZRVJRzGxC6L2bxQqoSLGm3MB2gwT8ABLPVrT4bCZqWtRLE5OzpgLsvs s8edTDqT4RcfrCLdxicIy00E9//gOA3S4xGthY3+Kpa3uYUifgYln2QjN6NVTA9RPHC2 5Nd9oaC0sXP5nH4JYLcFvHG5sMhDnLup70JyCR6ebzGkfFrRzPOAhl87DeL+3N8v0y1H vEbfsJZhDyvYDI3yThiZyGxlp25JHeLVR21qAA8mbKvPI4yGfAe6vNVnNE+rotc18pro Kvh7zUlgheasMmBJ38vS45WBsyCp2YzPIXbXqS1P4bJ3Bka0ssrV0DVPn1zByJgbHSgT vGPw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:content-transfer-encoding :content-id:spamdiagnosticmetadata:spamdiagnosticoutput:bcl :content-language:accept-language:in-reply-to:references:message-id :date:thread-index:thread-topic:subject:cc:to:from:dkim-signature; bh=LnolxkDOjh220jE2D4msNSmebg1Dzf/sqMksDrflXuM=; b=R4y5Du6wegPbgRmPfpAQT/+aKo4NJsiPsJljcOkeJiUjr8EmyxGBeg1t5qRwmMv/6F SRdR8SBV+gGyCEiQa00Ox8PTsuYeu8eEvxq3IFD2AExXE7jewrTbxXSJ2aV+5L6mE8VX CW+CdgsHxFz50haZCIQPAtoDxf1MNJtW0XI0NI988ZdGRzP7yFgf13PEsOa9NuI7VDn2 JU/zI/OJsE9fxNhcAmuH9HTz7FjXQf4wT3GoGFZxTdLlQbe6OdjbJwFnILoysYjCHK/Q c5kPk3Cl/rylHyY86nNH7WDId7kRTVXIo4U6G/YTGXeU6LSFozpCXeflMvpHlvjgKkMN Vsjw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@vmware.com header.s=selector1 header.b=ikqiENZS; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=vmware.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id u1-v6si4521524pgq.1.2018.10.04.03.23.40; Thu, 04 Oct 2018 03:23:55 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@vmware.com header.s=selector1 header.b=ikqiENZS; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=vmware.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727279AbeJDRQK (ORCPT + 99 others); Thu, 4 Oct 2018 13:16:10 -0400 Received: from mail-eopbgr680083.outbound.protection.outlook.com ([40.107.68.83]:26400 "EHLO NAM04-BN3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727109AbeJDRQK (ORCPT ); Thu, 4 Oct 2018 13:16:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=vmware.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=LnolxkDOjh220jE2D4msNSmebg1Dzf/sqMksDrflXuM=; b=ikqiENZShh5TaGSVimygiWg2iw/FzG/l2pD2x0AKEyeaTWg5oPXmyNaGErUmUzpweiy58LxcOnO+i9dVbSweUSrvxIIE51j9RExxXB5ScqnmXcmOWna7YKpu/jN5D6pmS75uP68vPGlcAf+oO8SV98wibVuqMhE2NxULTJsjplM= Received: from BYAPR05MB4776.namprd05.prod.outlook.com (52.135.233.146) by BYAPR05MB4341.namprd05.prod.outlook.com (52.135.202.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1207.18; Thu, 4 Oct 2018 10:23:29 +0000 Received: from BYAPR05MB4776.namprd05.prod.outlook.com ([fe80::49cd:7d04:35b7:b2a2]) by BYAPR05MB4776.namprd05.prod.outlook.com ([fe80::49cd:7d04:35b7:b2a2%3]) with mapi id 15.20.1207.018; Thu, 4 Oct 2018 10:23:29 +0000 From: Nadav Amit To: Ingo Molnar CC: "hpa@zytor.com" , Ingo Molnar , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , Thomas Gleixner , Jan Beulich , Josh Poimboeuf , Linus Torvalds , Peter Zijlstra , Andy Lutomirski Subject: Re: [PATCH v9 04/10] x86: refcount: prevent gcc distortions Thread-Topic: [PATCH v9 04/10] x86: refcount: prevent gcc distortions Thread-Index: AQHUW2CZEG0GJCpfDkK4fEgcOSwgMqUOuSmAgAAJ9ICAAAHlAIAABIuAgAAEaQCAAAT8gIAABDiAgAAKqIA= Date: Thu, 4 Oct 2018 10:23:29 +0000 Message-ID: <29591D3B-D49B-4D7A-B280-85A2C3F63F9C@vmware.com> References: <20181003213100.189959-1-namit@vmware.com> <20181003213100.189959-5-namit@vmware.com> <20181004075755.GA3353@gmail.com> <20181004083333.GA9802@gmail.com> <10D29A50-C352-4407-A824-0C3C06CD8592@zytor.com> <20181004091222.GB21864@gmail.com> <20181004094519.GA97692@gmail.com> In-Reply-To: <20181004094519.GA97692@gmail.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [66.170.99.1] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;BYAPR05MB4341;20:Ye+6LjcMMVpS3h/Cck0KIhn2L/gsqRFRO6WZ1Uggm4Jc2hseMidB/VmIhuWSqTjxvqlHeantOmRyfDPDfNNYuaFDTLyfSsMy9HVM+zaS/AdGBnLRQHc+Mk7iDc7h3ppl4AV3+R6V7ry9gRoT//FAxS0m/OTxwdPZGeF8+umulrs= x-ms-exchange-antispam-srfa-diagnostics: SOS; x-ms-office365-filtering-correlation-id: a5a9d07e-d716-45ad-43e0-08d629e36de0 x-microsoft-antispam: BCL:0;PCL:0;RULEID:(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600074)(711020)(2017052603328)(7153060)(7193020);SRVR:BYAPR05MB4341; x-ms-traffictypediagnostic: BYAPR05MB4341: bcl: 0 x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(61668805478150); x-ms-exchange-senderadcheck: 1 x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(8211001083)(6040522)(2401047)(5005006)(8121501046)(10201501046)(3231355)(944501410)(52105095)(93006095)(93001095)(3002001)(149066)(150057)(6041310)(20161123564045)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123562045)(20161123560045)(20161123558120)(201708071742011)(7699051)(76991048);SRVR:BYAPR05MB4341;BCL:0;PCL:0;RULEID:;SRVR:BYAPR05MB4341; x-forefront-prvs: 0815F8251E x-forefront-antispam-report: SFV:NSPM;SFS:(10009020)(346002)(376002)(396003)(136003)(39860400002)(366004)(199004)(189003)(8676002)(2906002)(33656002)(6506007)(71200400001)(71190400001)(229853002)(6916009)(54906003)(93886005)(316002)(6436002)(97736004)(66066001)(83716004)(6486002)(82746002)(105586002)(6512007)(81166006)(478600001)(53936002)(25786009)(102836004)(2616005)(476003)(186003)(26005)(68736007)(4326008)(99286004)(7416002)(14454004)(11346002)(81156014)(76176011)(7736002)(486006)(86362001)(5660300001)(305945005)(6346003)(446003)(5250100002)(2900100001)(8936002)(6116002)(256004)(3846002)(6246003)(36756003)(14444005)(106356001);DIR:OUT;SFP:1101;SCL:1;SRVR:BYAPR05MB4341;H:BYAPR05MB4776.namprd05.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; received-spf: None (protection.outlook.com: vmware.com does not designate permitted sender hosts) authentication-results: spf=none (sender IP is ) smtp.mailfrom=namit@vmware.com; x-microsoft-antispam-message-info: pZsCcSVtKSC3dkXrk1gR8Y3B1WjDHM/VEPfzsmYFftduOSAZjFd5x3wVzXKWLAalVYtpxiu6+YsbYtgWDYX6ng1J7Y2ogV3f4Nj2KFk1ygM235JsZoRJGW3LnvW7OfpvNtIoaXMHPgi1s2Ug1990jYIpDZGqB6E7theYxecpQgguVAdLrpjZyvG16O1WAY2yCl16UU3TwkKQplAlQVacdR3RWF5C3rs3CIzRGNZIDiRDsT65g6i5N6kixEj+rhz6YZyCo2KKumDJF6FKAnyEpGi7pD2vAGgq029Ds6q0M3nmCn6MUXLxoI1KF8N6VTEol6hH769Fxf0ln9OMA2RDBUvXlbaGr6S9wwZww41MpNQ= spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM 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-Network-Message-Id: a5a9d07e-d716-45ad-43e0-08d629e36de0 X-MS-Exchange-CrossTenant-originalarrivaltime: 04 Oct 2018 10:23:29.5357 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: b39138ca-3cee-4b4a-a4d6-cd83d9dd62f0 X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR05MB4341 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org YXQgMjo0NSBBTSwgSW5nbyBNb2xuYXIgPG1pbmdvQGtlcm5lbC5vcmc+IHdyb3RlOg0KDQo+IA0K PiAqIE5hZGF2IEFtaXQgPG5hbWl0QHZtd2FyZS5jb20+IHdyb3RlOg0KPiANCj4+PiBBbm90aGVy LCBzZXBhcmF0ZSBxdWVzdGlvbiBJIHdhbnRlZCB0byBhc2s6IGhvdyBkbyB3ZSBlbnN1cmUgdGhh dCB0aGUga2VybmVsIHN0YXlzIGZpeGVkPw0KPj4+IEkuZS4gaXMgdGhlcmUgc29tZSB0b29saW5n IHdlIGNhbiB1c2UgdG8gYWN0dWFsbHkgbWVhc3VyZSB3aGV0aGVyIHRoZXJlJ3MgYmFkIGlubGlu aW5nIGRlY2lzaW9ucyANCj4+PiBkb25lLCB0byBkZXRlY3QgYWxsIHRoZXNlIGJhZCBwYXR0ZXJu cyB0aGF0IGNhdXNlIGJhZCBHQ0MgY29kZSBnZW5lcmF0aW9uPw0KPj4gDQo+PiBHb29kIHF1ZXN0 aW9uLiBGaXJzdCwgSeKAmWxsIGluZGljYXRlIHRoYXQgdGhpcyBwYXRjaC1zZXQgZG9lcyBub3Qg aGFuZGxlIGFsbA0KPj4gdGhlIGlzc3Vlcy4gVGhlcmUgaXMgc3RpbGwgdGhlIGlzc3VlIG9mIGNv bmRpdGlvbmFsIHVzZSBvZg0KPj4gX19idWlsdGluX2NvbnN0YW50X3AoKS4NCj4+IA0KPj4gT25l IGluZGljYXRpb24gZm9yIGJhZCBpbmxpbmluZyBkZWNpc2lvbnMgaXMgdGhlIGlubGluZWQgZnVu Y3Rpb25zIGhhdmUNCj4+IG11bHRpcGxlIChub24taW5saW5lZCkgaW5zdGFuY2VzIGluIHRoZSBi aW5hcnkgYW5kIGFyZSBzaG9ydC4gSSBkb27igJl0DQo+PiBoYXZlIGFuIGF1dG9tYXRpYyBzb2x1 dGlvbiwgYnV0IHlvdSBjYW4gdHJ5LCBmb3IgZXhhbXBsZSB0byBydW46DQo+PiANCj4+IG5tIC0t cHJpbnQtc2l6ZSAuL3ZtbGludXggfCBncmVwICcgdCAnIHwgY3V0IC1kJyAnIC1mMi0gfCBzb3J0 IHwgdW5pcSAtYyB8IFwNCj4+IAlncmVwIC12ICdeICAgICAgMScgfCBzb3J0IC1uIC1yIHwgaGVh ZCAtbiA1DQo+PiANCj4+IFRoZXJlIGFyZSBob3dldmVyIG1hbnkgZmFsc2UgcG9zaXRpdmVzLiBB ZnRlciB0aGVzZSBwYXRjaGVzLCBmb3IgZXhhbXBsZSwgSQ0KPj4gZ2V0Og0KPj4gDQo+PiAgICAg MTEgMDAwMDAwMDAwMDAwMDEyZiB0IGpoYXNoDQo+PiAgICAgIDcgMDAwMDAwMDAwMDAwMDAxNyB0 IGRzdF9vdXRwdXQNCj4+ICAgICAgNiAwMDAwMDAwMDAwMDAwMDExIHQga3phbGxvYw0KPj4gICAg ICA1IDAwMDAwMDAwMDAwMDAwMmYgdCBhY3BpX29zX2FsbG9jYXRlX3plcm9lZA0KPj4gICAgICA1 IDAwMDAwMDAwMDAwMDAwMjkgdCBhY3BpX29zX2FsbG9jYXRlDQo+PiANCj4+IA0KPj4gamhhc2go KSBzaG91bGQgbm90IGhhdmUgYmVlbiBpbmxpbmVkIGluIG15IG1pbmQsIGFuZCBzaG91bGQgaGF2 ZSBhDQo+PiBub24taW5saW5lZCBpbXBsZW1lbnRhdGlvbi4gZHN0X291dHB1dCgpIGlzIHVzZWQg YXMgYSBmdW5jdGlvbiBwb2ludGVyLg0KPj4ga3phbGxvYygpIGFuZCB0aGUgbmV4dCB0d28gc3Vm ZmVyIGZyb20gdGhlIF9fYnVpbHRpbl9jb25zdGFudF9wKCkgcHJvYmxlbSBJDQo+PiBkZXNjcmli ZWQgaW4gdGhlIHBhc3QuDQo+IA0KPiBPaywgdGhhdCdzIHVzZWZ1bCBpbmZvLg0KPiANCj4gVGhl IGhpc3RvZ3JhbSBzdWdnZXN0cyB0aGF0IHdpdGggYWxsIHlvdXIgcGF0Y2hlcyBhcHBsaWVkIHRo ZSBrZXJuZWwgaXMgbm93IGluIGEgcHJldHR5IGdvb2QgDQo+IHN0YXRlIGluIHRlcm1zIG9mIGlu bGluaW5nIGRlY2lzaW9ucywgcmlnaHQ/DQoNCkl0IHdhcyBqdXN0IGFuIGV4YW1wbGUgdGhhdCBJ IHJhbiBvbiB0aGUga2VybmVsIEkgYnVpbHQgcmlnaHQgbm93ICh3aXRoIGENCmN1c3RvbSBjb25m aWcpLiBQbGVhc2UgZG9u4oCZdCByZWdhcmQgdGhlc2UgcmVzdWx0cyBhcyBhbnl0aGluZyBpbmRp Y2F0aXZlLg0KDQo+IEFyZSB5b3UgdXNpbmcgZGVmY29uZmlnIG9yIGEgcmVhc29uYWJsZSBkaXN0 cm8tY29uZmlnIGZvciB5b3VyIHRlc3RzPw0KDQpJIHRoaW5rIGl0IGlzIGJlc3QgdG8gdGFrZSB0 aGUga2VybmVsIGFuZCBydW4gbG9jYWx5ZXNjb25maWcgZm9yIHRlc3RpbmcuDQoNClRha2luZyBV YnVudHUgMTguMDQgYW5kIGRvaW5nIHRoZSBzYW1lIGdpdmVzIHRoZSBmb2xsb3dpbmcgcmVzdWx0 czoNCg0KICAgICAxMiAwMDAwMDAwMDAwMDAwMTJmIHQgamhhc2gNCiAgICAgIDcgMDAwMDAwMDAw MDAwMDAxNyB0IGRzdF9vdXRwdXQNCiAgICAgIDcgMDAwMDAwMDAwMDAwMDAxNCB0IGluaXRfb25j ZQ0KICAgICAgNSAwMDAwMDAwMDAwMDAwMGQ4IHQgamhhc2gyDQogICAgICA1IDAwMDAwMDAwMDAw MDAwNGUgdCBwdXRfcGFnZQ0KICAgICAgNSAwMDAwMDAwMDAwMDAwMDJmIHQgYWNwaV9vc19hbGxv Y2F0ZV96ZXJvZWQNCiAgICAgIDUgMDAwMDAwMDAwMDAwMDAyOSB0IGFjcGlfb3NfYWxsb2NhdGUN CiAgICAgIDUgMDAwMDAwMDAwMDAwMDAyOCB0IHVtYXNrX3Nob3cNCiAgICAgIDUgMDAwMDAwMDAw MDAwMDAxMSB0IGt6YWxsb2MNCiAgICAgIDQgMDAwMDAwMDAwMDAwMDA1MyB0IHRyYWNlX3hoY2lf ZGJnX3F1aXJrcw0KDQpOb3QgYXdmdWwsIGJ1dCBub3QgZ3JlYXQuDQoNCkl0IGlzIGEgYml0IGhh cmQgdG8gZml4IHRoZSBfX2J1aWx0aW5fY29uc3RhbnRfcCgpIHByb2JsZW0gd2l0aG91dCBoYXZp bmcNCnNvbWUgbmVnYXRpdmUgc2lkZS1lZmZlY3RzLg0KDQpSZW1pbmRlcjogX19idWlsdGluX2Nv bnN0YW50X3AoKSBpcyBldmFsdWF0ZWQgYWZ0ZXIgdGhlIGlubGluaW5nIGRlY2lzaW9uDQphcmUg ZG9uZS4gWW91IGNhbiB1c2UgX19idWlsdGluX2Nob29zZV9leHByKCkgaW5zdGVhZCBvZiBhbiDi gJxpZuKAnXMgYW5kDQppbnN0ZWFkIG9mIHRlcm5hcnkgb3BlcmF0b3JzIHdoZW4gZXZhbHVhdGlu ZyBfX2J1aWx0aW5fY29uc3RhbnRfcCgpIHRvIHNvbHZlDQp0aGUgcHJvYmxlbS4gSG93ZXZlciwg dGhpcyBjYXVzZXMgdGhlIGNvbXBpbGVyIG5vdCB0byBrbm93IHNvbWV0aW1lcyB0aGF0IGENCnZh bHVlIGlzIGNvbnN0YW50IGJlY2F1c2UgX19idWlsdGluX2Nob29zZV9leHByICgpIGV2YWx1YXRp b24gaGFwcGVucyB0b28NCmVhcmx5LiBUaGlzIF9fYnVpbHRpbl9jaG9vc2VfZXhwcigpIHByb2Js ZW0gaXMgdGhlIHJlYXNvbiBmb3IgcHV0X3BhZ2UoKSBhbmQNCmt6YWxsb2MoKSBhcmUgbm90IGJl aW5nIGlubGluZWQuIENsYW5nLCBhZ2FpbiwgZG9lcyBub3Qgc3VmZmVyIGZyb20gdGhpcw0KcHJv YmxlbS4NCg0KQW55aG93LCBpdCBtYXkgYmUgYSBnb29kIHByYWN0aWNlIHRvIHRyeSB0byBnZXQg cmlkIG9mIHRoZSByZXN0LiBGb3INCmV4YW1wbGUsIGRzdF9kaXNjYXJkKCkgaGFzIGZvdXIgaW5z dGFuY2VzIGJlY2F1c2UgaXQgaXMgYWx3YXlzIGdpdmVuIGFzIGENCmZ1bmN0aW9uIHBvaW50ZXIu IFNvIGl0IHNob3VsZCBub3QgaGF2ZSBiZWVuIGlubGluZWQuDQoNClJlZ2FyZHMsDQpOYWRhdg==