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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 AEB51C3A589 for ; Tue, 20 Aug 2019 16:05:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5FA3322DD6 for ; Tue, 20 Aug 2019 16:05:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="B6Ic+tmr"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="NY226oIE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FA3322DD6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=fb.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 03B376B0266; Tue, 20 Aug 2019 12:05:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F2DED6B0269; Tue, 20 Aug 2019 12:05:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DCFC66B026A; Tue, 20 Aug 2019 12:05:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0135.hostedemail.com [216.40.44.135]) by kanga.kvack.org (Postfix) with ESMTP id BB21C6B0266 for ; Tue, 20 Aug 2019 12:05:57 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 6E0A1180AD7C3 for ; Tue, 20 Aug 2019 16:05:57 +0000 (UTC) X-FDA: 75843282354.19.sleep21_16cd4a8facc0d X-HE-Tag: sleep21_16cd4a8facc0d X-Filterd-Recvd-Size: 9743 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Tue, 20 Aug 2019 16:05:56 +0000 (UTC) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7KFnobm004554; Tue, 20 Aug 2019 09:05:48 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=facebook; bh=If66QaEQSLNceea86j1WT0DnyltAlVduRJVfmvuWcdw=; b=B6Ic+tmreSTmrXXIGC1TcnQQvQMgKTBNv4wZ/B/ssUqXUaspyh4AiUUikw0eKRTZbwSB DA8zqF1hoOXMpotYC31dNqvupIwztLqZTlr1aa68KZQaBXQsoURzlwlL5Q3/TGcrKBZu 6+bxW0UpGwSX0rHSQqQeXumQYE0hEy0pMZ4= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 2ugjxd8ccw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Tue, 20 Aug 2019 09:05:48 -0700 Received: from ash-exhub204.TheFacebook.com (2620:10d:c0a8:83::4) by ash-exhub103.TheFacebook.com (2620:10d:c0a8:82::c) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Tue, 20 Aug 2019 09:05:47 -0700 Received: from NAM05-CO1-obe.outbound.protection.outlook.com (100.104.31.183) by o365-in.thefacebook.com (100.104.36.100) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1713.5 via Frontend Transport; Tue, 20 Aug 2019 09:05:47 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=GECa1CRLsxEHC3EFeW5xTK6NPsmm+Xor2qhHHe8ovmT4vTMS+OlR1cE7mQyJOIUYoo7rHsd+ZB+RMnBeEBckadPwIlxsvJcmUn3dg3X81vkmLyrA5HIKEqqvO/sl/0JzXrqDPAYCjJiWXaBhFylgNN0BD78Ivare/z9VQuzf/3L4HJde22wWp8/tt0QkFm6EyDOCP9oyvNAywZorXJvOeSt1RMntmYmyWLr37nuabik5A3v5VdAv4ooNXh7b3oLEtdJJoqCN1yWp0kT0hPQhbb2TIGKUcxgoTX+MZKmZM2CmS6XFXOKUjQ4EeQAcmiI2fc/2q9hMHn9dXaJkMhMnvw== 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=If66QaEQSLNceea86j1WT0DnyltAlVduRJVfmvuWcdw=; b=LKLSz3V/g7NUtsMDE9s/ekoiknB5EpUzowZIsfRAesIRUqHBuu7E8jVSPjruHhIc6YWNVmu0DU0sZeBwYMHyG6BihFpX9WPPk47drQtxsx1hfE4wkNC9o4LzJFxRNVlzOJjFbTK4KiXAH+/j7a4VcPKruU2NOwjW0YUXz2rS5N8nucsnOnI8FsB2t4hFshRZ6LmFOrvGF/EKIBTVNUgO304XD1GtOUkILJTJZ81gUCyDM05urBKNBIjwsQ9YTBC5/3xzahZmm+SRuqs2tUnqXTgs6DmzeSaheKGPoVRejesYOA4jD5hlvjxI/0NxtIE7kpLzutK0vq/EI5WV4Am2/w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=fb.com; dmarc=pass action=none header.from=fb.com; dkim=pass header.d=fb.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector2-fb-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=If66QaEQSLNceea86j1WT0DnyltAlVduRJVfmvuWcdw=; b=NY226oIEy4+x2AaUG3sRP3Ypjlk5tTBkS6qzWnBnXa7h8hrLL/jfsJ1hQOQmJpwvSMnlVsjM3hSC4NsgCRL73BpFojui/rbDqNsDfCOvYKNM4how21UyGHlRPLEsE/sAwpHu94CZMhXXF/OHaZW3aUOTBWUvxrBZXr2b3cES3mo= Received: from MWHPR15MB1165.namprd15.prod.outlook.com (10.175.3.22) by MWHPR15MB1375.namprd15.prod.outlook.com (10.173.233.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2178.16; Tue, 20 Aug 2019 16:05:46 +0000 Received: from MWHPR15MB1165.namprd15.prod.outlook.com ([fe80::45ee:bc50:acfa:60a5]) by MWHPR15MB1165.namprd15.prod.outlook.com ([fe80::45ee:bc50:acfa:60a5%3]) with mapi id 15.20.2178.018; Tue, 20 Aug 2019 16:05:46 +0000 From: Song Liu To: Dave Hansen CC: Linux Kernel Mailing List , Linux MM , Kernel Team , "stable@vger.kernel.org" , Joerg Roedel , Thomas Gleixner , Dave Hansen , Andy Lutomirski , "Peter Zijlstra" Subject: Re: [PATCH] x86/mm/pti: in pti_clone_pgtable() don't increase addr by PUD_SIZE Thread-Topic: [PATCH] x86/mm/pti: in pti_clone_pgtable() don't increase addr by PUD_SIZE Thread-Index: AQHVVywgQMe0L9XqWkSJYmnWEvsfracED/kAgAAEv4CAAAEbAIAAHhOA Date: Tue, 20 Aug 2019 16:05:45 +0000 Message-ID: References: <20190820075128.2912224-1-songliubraving@fb.com> <520249E9-1784-4728-88D7-5A21DFE17B8E@fb.com> <463379e3-5a31-5064-dd02-ea2fe149fa7e@intel.com> In-Reply-To: <463379e3-5a31-5064-dd02-ea2fe149fa7e@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: Apple Mail (2.3445.104.11) x-originating-ip: [2620:10d:c090:200::2:8c4e] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 17687d25-8bfe-44ac-66d7-08d7258842a5 x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600148)(711020)(4605104)(1401327)(2017052603328)(7193020);SRVR:MWHPR15MB1375; x-ms-traffictypediagnostic: MWHPR15MB1375: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:5236; x-forefront-prvs: 013568035E x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(396003)(136003)(346002)(376002)(39860400002)(366004)(199004)(189003)(102836004)(478600001)(71190400001)(14454004)(71200400001)(99286004)(76176011)(14444005)(66946007)(4326008)(81156014)(6486002)(64756008)(76116006)(256004)(66476007)(6512007)(8936002)(229853002)(25786009)(50226002)(6436002)(81166006)(66556008)(66446008)(8676002)(186003)(5660300002)(486006)(6916009)(53936002)(6246003)(446003)(57306001)(6116002)(2906002)(6506007)(53546011)(11346002)(36756003)(86362001)(54906003)(46003)(7736002)(305945005)(316002)(33656002)(476003)(2616005);DIR:OUT;SFP:1102;SCL:1;SRVR:MWHPR15MB1375;H:MWHPR15MB1165.namprd15.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; received-spf: None (protection.outlook.com: fb.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam-message-info: tn3iLESiiYjG3cDAVp5aNItL2nXW/8uloVv8gwCmGjwOM8hxZO82akiOt6sWDGmu7FIsg2utk3JVa/fVyoF17BKYFV3Objbw7q28M1t+L3YvZ4IJn9KHXYc+XrpqkGBlsbARkvzKmLCn5DIHdY0RfqnM4rmREF4PZje65mGfUTTAmgbsvGs11keZg6J9P3qMniW4f1bLzjfDhPYB08+nXE6SVv8u8qtxF8PnQe4c6slv1fwjZ7MIgfTTAx7AkQkVBLtAcHt5ntJqmGaX048z5P9hEF8S4uolkc1wgDZO/ra/TEtJ8/mgplK9189d1DtURxtfj8XPQ+3ekngep0z19Vfjjk/64kLwa1t7fISTUAISU086tUaZAi0vet9ywIqQ+JHzuxf/vO8xjFKQNupokzgsy4j8cTMLoMKOGn0TcNI= Content-Type: text/plain; charset="us-ascii" Content-ID: <867AF1B8D022F5428B01A990A62E7921@namprd15.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: 17687d25-8bfe-44ac-66d7-08d7258842a5 X-MS-Exchange-CrossTenant-originalarrivaltime: 20 Aug 2019 16:05:45.8306 (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: nQrW9FRZRlJ28bU4lcVACMJsXNDpHbMOJyuM1OBHkIpPUEAMs7GRx6wKGwWduTulAsouySMfIs4j2IdelCvm+A== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR15MB1375 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-08-20_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=862 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908200149 X-FB-Internal: deliver 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: > On Aug 20, 2019, at 7:18 AM, Dave Hansen wrote: >=20 > On 8/20/19 7:14 AM, Song Liu wrote: >>> *But*, that shouldn't get hit on a Skylake CPU since those have PCIDs >>> and shouldn't have a global kernel image. Could you confirm whether >>> PCIDs are supported on this CPU? >> Yes, pcid is listed in /proc/cpuinfo.=20 >=20 > So what's going on? Could you confirm exactly which pti_clone_pgtable() > is causing you problems? Do you have a theory as to why this manifests > as a performance problem rather than a functional one? >=20 > A diff of these: >=20 > /sys/kernel/debug/page_tables/current_user > /sys/kernel/debug/page_tables/current_kernel >=20 > before and after your patch might be helpful. I believe the difference is from the following entries (7 PMDs) Before the patch: current_kernel: 0xffffffff81000000-0xffffffff81e04000 14352K ro = GLB x pte efi: 0xffffffff81000000-0xffffffff81e04000 14352K ro = GLB x pte kernel: 0xffffffff81000000-0xffffffff81e04000 14352K ro = GLB x pte After the patch: current_kernel: 0xffffffff81000000-0xffffffff81e00000 14M ro = PSE GLB x pmd efi: 0xffffffff81000000-0xffffffff81e00000 14M ro PSE= GLB x pmd kernel: 0xffffffff81000000-0xffffffff81e00000 14M ro = PSE GLB x pmd current_kernel and kernel show same data though.=20 Thanks, Song