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 90FDCC54EE9 for ; Tue, 27 Sep 2022 17:30:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F32888E00EE; Tue, 27 Sep 2022 13:30:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EE1FA8E00C1; Tue, 27 Sep 2022 13:30:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D5A9E8E00EE; Tue, 27 Sep 2022 13:30:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id C71B28E00C1 for ; Tue, 27 Sep 2022 13:30:43 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 986C4120860 for ; Tue, 27 Sep 2022 17:30:43 +0000 (UTC) X-FDA: 79958555166.18.6536EFA Received: from na01-obe.outbound.protection.outlook.com (mail-eastusazon11010008.outbound.protection.outlook.com [52.101.51.8]) by imf28.hostedemail.com (Postfix) with ESMTP id 06E08C0010 for ; Tue, 27 Sep 2022 17:30:42 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=VhWqXq9kG5xazFhOfGYSs7JUakC6RdrsY/Z3E0oXyk9n7w5+xOAsB7onowtYjXPKb9C3Eq5ecQjQdPr+9iJjA/rBAg3g8oH6uaMA9q3YQHvM2J8jPvObHR6q3JQ289OwX19eOlz7vqBpIbhlRxE/QcLVG4HM/STFAO/LrQ4d+ZfPOd85k7vdPTrnUgDbMI6AG4mnkD17Afn1jBCySRh12r8CiE9vMAt+gMEojDMOeTKqk4t0n5J4+Y4zjXs+wlfSp7n5AuJk7/uElKmxSQ7GfuFSrQi9ksGPAfgFfRNibHh4bO9S8ydWCghDwfLrJEw3YJbaNS2cJ5Idf1TKwGRkqw== 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=JtzeYhySMjvQmHWlSL2i9vWhVHc1bGQZ0Az2MvwbdyI=; b=mqjMo4Z02KkES0e4H5n8Jp4io1j7tFoVOtBNx1wSapM6MbXLuLssH0YIs4uaLO4CxAgxFW0j22td9GjxMOD+nLcYoQ0VCfvZ06zzWIqrHsTX+0LACpLOjdn3gu/IIfSLRa4welvACQyw+FZHjiXKBy2jW7mn3fyLY22LeaijOJPEkm4t0ywP5ToqUKLWaazyayRr1RDgPIzmjQINB0tIVsjbZ6+mKRcY2XPwr8QHCeYznXK8xNC/A8e8asqjI0RpsdeJze/zvJYcuJelheI/em22UA358HjKS9+HgzvmDRrX5Ux4VnL2beTimzrPqfKHOWrvJBEkLqn9hSlu25JyzA== 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=JtzeYhySMjvQmHWlSL2i9vWhVHc1bGQZ0Az2MvwbdyI=; b=YBrwbxUZAUwGMRDqDN+kXT5+f9FCodgiQU58Lu5/nai9B/rGGhykeuWfQxuwoQehH3LQvAtwBaKGmvvJHpVMxu1M9AuIMpw3W16tur1GXru4xt0ivP4VCV1bdJ0lOXL+1HoDhJ3nDtCcqJ9lj4Qp/MK02s8OjpKKulls879iW/8= Received: from BY3PR05MB8531.namprd05.prod.outlook.com (2603:10b6:a03:3ce::6) by BN3PR05MB2418.namprd05.prod.outlook.com (2a01:111:e400:7bb4::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5676.8; Tue, 27 Sep 2022 17:30:39 +0000 Received: from BY3PR05MB8531.namprd05.prod.outlook.com ([fe80::942c:7d1b:6b3d:85b6]) by BY3PR05MB8531.namprd05.prod.outlook.com ([fe80::942c:7d1b:6b3d:85b6%5]) with mapi id 15.20.5676.015; Tue, 27 Sep 2022 17:30:39 +0000 From: Nadav Amit To: Chih-En Lin CC: Andrew Morton , Qi Zheng , David Hildenbrand , Matthew Wilcox , Christophe Leroy , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Luis Chamberlain , Kees Cook , Iurii Zaikin , Vlastimil Babka , William Kucharski , "Kirill A . Shutemov" , Peter Xu , Suren Baghdasaryan , Arnd Bergmann , Tong Tiangen , Pasha Tatashin , Li kunyu , Anshuman Khandual , Minchan Kim , Yang Shi , Song Liu , Miaohe Lin , Thomas Gleixner , Sebastian Andrzej Siewior , Andy Lutomirski , Fenghua Yu , Dinglan Peng , Pedro Fonseca , Jim Huang , Huichun Feng Subject: Re: [RFC PATCH v2 3/9] mm, pgtable: Add ownership to PTE table Thread-Topic: [RFC PATCH v2 3/9] mm, pgtable: Add ownership to PTE table Thread-Index: AQHY0o4d02iFGEmJ0k6DfjGH6P+1aK3ziJsA Date: Tue, 27 Sep 2022 17:30:39 +0000 Message-ID: <2A6CA595-1F8D-4A83-9E85-E2C4392395CB@vmware.com> References: <20220927162957.270460-1-shiyn.lin@gmail.com> <20220927162957.270460-4-shiyn.lin@gmail.com> In-Reply-To: <20220927162957.270460-4-shiyn.lin@gmail.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: Apple Mail (2.3696.120.41.1.1) x-ms-publictraffictype: Email x-ms-traffictypediagnostic: BY3PR05MB8531:EE_|BN3PR05MB2418:EE_ x-ms-office365-filtering-correlation-id: 03d62068-df04-48af-1884-08daa0adfeed 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:(13230022)(4636009)(39860400002)(376002)(136003)(366004)(396003)(346002)(451199015)(7416002)(122000001)(2906002)(66556008)(64756008)(53546011)(7406005)(41300700001)(83380400001)(6506007)(76116006)(66946007)(6512007)(5660300002)(478600001)(38070700005)(8936002)(38100700002)(36756003)(6486002)(26005)(71200400001)(6916009)(186003)(54906003)(8676002)(86362001)(33656002)(316002)(4326008)(66446008)(66476007)(2616005)(45980500001);DIR:OUT;SFP:1101; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?HMKA7SzJTN9FS1YIce3SKGZ3HoBsCoe1HY2gTKPJD0O9+xne+WBoPH1+RwtY?= =?us-ascii?Q?r2dhvtjCMrT2EJCzp22y0S1dY9bYGp66fCjyNgHMdJM9Xh17s2hOFf1gMqew?= =?us-ascii?Q?cHdDPAI6Avzg0Ik3wHgnz838j41LNfFqjk6KK9wo6IfD+4gxcQydAitkoXAE?= =?us-ascii?Q?jsXNZtKu8LtvoOiCu7OQHZTF/tBAu3QKOVgjysXBuX6ThFPNCDgG7Wpt1AjR?= =?us-ascii?Q?/CrftbSELFagxpwJSXoO5SpguBXw5UBTE/9H3XL43TvWgzLJkr9S2bLOu5jM?= =?us-ascii?Q?gifu+1bR2FBbG9CdjrMMyck5QXj/3Z5cWaQdjH9I2r9uASv8F2shhKFYis3e?= =?us-ascii?Q?mSbuIgZK9oaB7BAsPq/fSBVzJSpgoY3tVLaQFMbuOKtD0Zn+AL9GRtj/d/Tx?= =?us-ascii?Q?LBHBxKUjsDGc+dSmtSWQ08S7Tw0B2BSUIjxXVUez0Fca3TgExA4ujXiEdh39?= =?us-ascii?Q?8auaMopRn+4UMmZPuIqjEleoQEIeTQfxIY2cEv5WkYmDpwWJiio2cExTLNlW?= =?us-ascii?Q?L7/NIn2Fx52GD1qBzH2jHAa6i6XS2PLoJL/ssajWfe74Xqm3Ypwi0wMV7YRU?= =?us-ascii?Q?OBRWrFmFBVUEwl8ROmq8kwj39wC2DDlb5h92UA8oq9id+7sm5uAjgA668WGc?= =?us-ascii?Q?QIekjy5Uc4Hy60gQYFlxscsUqKuPZ+q/0uS+telGPEj2WjxWKPoq0HFRe3MA?= =?us-ascii?Q?d5AuJHSq/7xdI0j+v6FMsddJleaD7Hg71DCctshD8GcM6VWxXaoM77errgYZ?= =?us-ascii?Q?fo5tcZmDwRzRduXTqLVaAxEseUvqe7vkwvO9hch7+m7dJ//Er/BGCA2Z0wlt?= =?us-ascii?Q?TgLcx4gvhQ32uanF1cCkIsh5q1o1KeoJ318Zy7mtOaphrt9f97lStTyR5Die?= =?us-ascii?Q?8h7UozJdRxqlAVpf+ZNgsrUw/mAmYlV/sybXkEp6/lMaSBQjyqU4Pwmg0IE6?= =?us-ascii?Q?QZvga//3PivDU9lYUI4IztI2sJmfOsiLbhZQXujDTAe+y1/oMD1jj8QuEWxY?= =?us-ascii?Q?hXnwVf4x6HSpv2HCPR0ukIH9yVHqu9dyOY3Li893mXt3fGZbuVMOC3K2FKF5?= =?us-ascii?Q?o7leshHhQUVovMdZ+Xp93DqPIEO9Znp0kQH0igrvuwmBW3tzWvmVb6qfySjC?= =?us-ascii?Q?7vsTcT3J6v/I1kqp0dZ7I2pye/BHkSvTmbyB22gASHegdy9b/mRmOrkW7A+h?= =?us-ascii?Q?Ew2AlpAvEu7tdyQV1xvZ5GL9oLq343DfqtTu/KDYEeUA4vkKmz6d2ey2Tjd0?= =?us-ascii?Q?k/K+fyPRsfDJOZXNYbm+D5ugj7/2vnnwLJawbEBmDCzrL8A5veNLLIxcZZqK?= =?us-ascii?Q?mWNFFoS3e87sPCXU/lWjmu9f52onmf1ChGEt6MgF9gcFm9P4bnLlq16T5g67?= =?us-ascii?Q?F6n39hs3LdbWOAo9/PoWTcYPkFuz3tC+i7imBV2bGRgKvHz0CbQkk7vUyeqi?= =?us-ascii?Q?j+TcGkRu/zzRxF6b1qyK40D+YUyIadVqqjfG7fR3xnlopFMBNFLzkH518pUv?= =?us-ascii?Q?UyN1sj0/dHacB0h/Tfy087gS9MyXr2gbADhtEF4GGWkzuayFdsjJY6+HMf0/?= =?us-ascii?Q?QkorkbAduxtT6Olh2vfRmy9rEJQR+FnDYjMkExJ6?= Content-Type: text/plain; charset="us-ascii" Content-ID: <2FABEF823C97AF4886BD7FA075BAE33E@namprd05.prod.outlook.com> Content-Transfer-Encoding: quoted-printable 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: 03d62068-df04-48af-1884-08daa0adfeed X-MS-Exchange-CrossTenant-originalarrivaltime: 27 Sep 2022 17:30:39.2772 (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: VzcoKrnSSzIW5BXvaGXcuN9PS7rkWK1o/K8l2PX37pBrNrsAgRYl+XJV8UIK716IcBZOCA5NNY9gfRolMVe7HA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN3PR05MB2418 ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1664299843; a=rsa-sha256; cv=pass; b=sHSQLfywfAvCipue85+HpdUviuFFdJ6kNlGycPwn7FBNLTVPmqHVUFKSV8cjb6cePxOT5m NE3DIahFUxnuiMCJ1inaFQMB+y6iQi7VgzqtoRoYvTQuVZtBi52oVnrD4QAIVHyXbOy7zq a5vJsm/C9jRlbg9rybWVdLMxIp6NClE= ARC-Authentication-Results: i=2; imf28.hostedemail.com; dkim=pass header.d=vmware.com header.s=selector2 header.b=YBrwbxUZ; spf=pass (imf28.hostedemail.com: domain of namit@vmware.com designates 52.101.51.8 as permitted sender) smtp.mailfrom=namit@vmware.com; dmarc=pass (policy=quarantine) header.from=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=1664299843; 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=JtzeYhySMjvQmHWlSL2i9vWhVHc1bGQZ0Az2MvwbdyI=; b=U9Tq5WQivoh+sRSLxRRXfELSCwfw9eCbTLze6zeaeKBpS0LUEylzEK+gYhsSbfM6iWY5GU QsCEFt9V2omStKnio6z7qOPkCo0JGJlkCUWcNLldpVM6smEqHB5LwDNakr5Za+lCXkTAxv qAL0wy3YLFWESvy3axtFu42fdCIESRs= X-Stat-Signature: 1rges169oyxdfj8najga6n7n7hsd9cnk X-Rspamd-Queue-Id: 06E08C0010 X-Rspam-User: Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=vmware.com header.s=selector2 header.b=YBrwbxUZ; spf=pass (imf28.hostedemail.com: domain of namit@vmware.com designates 52.101.51.8 as permitted sender) smtp.mailfrom=namit@vmware.com; dmarc=pass (policy=quarantine) header.from=vmware.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") X-Rspamd-Server: rspam01 X-HE-Tag: 1664299842-298844 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 Sep 27, 2022, at 9:29 AM, Chih-En Lin wrote: > Introduce the ownership to the PTE table. It uses the address of PMD > index to track the ownership to identify which process can update > their page table state from the COWed PTE table. >=20 > Signed-off-by: Chih-En Lin > --- > include/linux/mm.h | 1 + > include/linux/mm_types.h | 5 ++++- > include/linux/pgtable.h | 10 ++++++++++ > 3 files changed, 15 insertions(+), 1 deletion(-) >=20 > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 21f8b27bd9fd3..965523dcca3b8 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -2289,6 +2289,7 @@ static inline bool pgtable_pte_page_ctor(struct pag= e *page) > return false; > __SetPageTable(page); > inc_lruvec_page_state(page, NR_PAGETABLE); > + page->cow_pte_owner =3D NULL; > return true; > } >=20 > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index cf97f3884fda2..42798b59cec4e 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -152,7 +152,10 @@ struct page { > struct list_head deferred_list; > }; > struct { /* Page table pages */ > - unsigned long _pt_pad_1; /* compound_head */ > + union { > + unsigned long _pt_pad_1; /* compound_head */ > + pmd_t *cow_pte_owner; /* cow pte: pmd */ > + }; > pgtable_t pmd_huge_pte; /* protected by page->ptl */ > unsigned long _pt_pad_2; /* mapping */ > union { > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index d03d01aefe989..9dca787a3f4dd 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -615,6 +615,16 @@ static inline int pte_unused(pte_t pte) > } > #endif >=20 > +static inline void set_cow_pte_owner(pmd_t *pmd, pmd_t *owner) > +{ > + smp_store_release(&pmd_page(*pmd)->cow_pte_owner, owner); > +} > + > +static inline bool cow_pte_owner_is_same(pmd_t *pmd, pmd_t *owner) > +{ > + return smp_load_acquire(&pmd_page(*pmd)->cow_pte_owner) =3D=3D owner; > +} Hiding synchronization primitives in such manner, and especially without proper comments, makes it hard to understand what the ordering is supposed to achieve.