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 44AAFC433FE for ; Sun, 30 Oct 2022 00:16:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 722BE8E0001; Sat, 29 Oct 2022 20:16:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6AB0F6B0073; Sat, 29 Oct 2022 20:16:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4FDE38E0001; Sat, 29 Oct 2022 20:16:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 38E486B0071 for ; Sat, 29 Oct 2022 20:16:22 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 02351C0A1C for ; Sun, 30 Oct 2022 00:16:21 +0000 (UTC) X-FDA: 80075699004.03.7FEBD8B Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf14.hostedemail.com (Postfix) with ESMTP id 5360B10000A for ; Sun, 30 Oct 2022 00:16:20 +0000 (UTC) Received: from pps.filterd (m0246627.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29TKK9g0012622; Sun, 30 Oct 2022 00:16:07 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=corp-2022-7-12; bh=tPsYwScA75zcoPjU6ZQCZx2s7XqRblCuzFqWsG+amoM=; b=oaWeDHFx4YApOnPE6qQmVvR+uDdt8bAOSbbLgs8jOrWMo1hW/bNFvcUBPeO6KyoDhJJa 4SWkKtu5nOdLe3G07QHck8OcHKo+kEWpH73pd1ImNyfYXvB27Fd8iLH71nSpq6lxoIPO +Cg6D1MYAaWi2uOpogmEHKXN/ElYoAcOY4Fb2dQLCd7gxLMEXohiFhdRMSpPgsgAUhfQ aP2HCCj6GE7GlPbxqT8zMByBuMqH9b8tNWZ1KRZOsSOtEvT4Ci+XfXr4VtLbotTvaUgF osfmK0u2dGsWRCCqlkO1RODxVjvH1l2yzKmZ9RFfxRLqRjg8nVtYJ/kobQZ9482uX+X/ ow== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3kgts10y4r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 30 Oct 2022 00:16:06 +0000 Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.5/8.17.1.5) with ESMTP id 29TNs0ur019481; Sun, 30 Oct 2022 00:16:05 GMT Received: from nam04-mw2-obe.outbound.protection.outlook.com (mail-mw2nam04lp2171.outbound.protection.outlook.com [104.47.73.171]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3kgtm836m2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 30 Oct 2022 00:16:05 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=ht6QxAoRFlbjchLmem+Bpo8Uv3762UcaWnfBNoynqvmWyeC7tXg4HKJuwKFodpPGhk0GzhDhW32dIRE1PzXi6dJtK6dgKnRtYdfGL+Jj7ko3jDS/+/QUB1uIgSbShtjc4PyU9wm9OKDqfvhNjjw7Kqg9WuAnCrjX2F6NrpbY0rqpjdvT653gyt2I9FSOCYOD8Y7XNL0U6kkAp1SpBtC+QwHioru2AbUwzYqO6NHXPBeNYSfgQHKjpQj25CD+f2puLKGKj2U20Q3SZr6HBm/EV831Ws2rB+qaFwOPwmgLUVIFHk9/PXq7ytWKtbiYgalm1EyLGq+/XiEzDLzD4ErTJQ== 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=tPsYwScA75zcoPjU6ZQCZx2s7XqRblCuzFqWsG+amoM=; b=fOaS7XCDpVR8LGSTrhRHfUsz/x4c0wgPqNV3X6YLMVNqmRqXToJAWCRVVX58x9MN5d/hCpUt/MRUgs7EMcOoMn36lRjtQtnaVJBcUfTQFRSVkyKZlIkeShmzDKaCnCJ12WoEB8OJcK7XQw3+LAGNbiEibzbTYqgixV/gMOCNL64YrL2rbMNGHnTFDTbr+XqvNvpDCpaNdJUMaby2MDPfrESk8cyWNdGVUdISgfm5TEw5msrV/TrqdYSocM84HUsWdL16NFuX/1R3pUnUzfuVKRT+ZrzrthcvojGR3U7bD444UP8H9T+Ysb/pR0ra0RTSmy444RBnyhkprnwaQrMoRg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=tPsYwScA75zcoPjU6ZQCZx2s7XqRblCuzFqWsG+amoM=; b=OG1/Kom1Qm57GQCCDjqwYyLoO94KqFsfC4QNRn43DaVEYoGK3Veyz5eOojow5R5CCueGQAgNcgDFn9eA02aJu2hcjnBxJCrGNelEp2VtGgMGvFMkV5zXrBhCSkf2M8r/akgiEBkoBMcDpOdiPL16mEArQN4uHlcIQeqfw6pEpqo= Received: from BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) by DS7PR10MB5904.namprd10.prod.outlook.com (2603:10b6:8:84::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5723.34; Sun, 30 Oct 2022 00:16:02 +0000 Received: from BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::58e9:95ba:d31e:ddd3]) by BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::58e9:95ba:d31e:ddd3%6]) with mapi id 15.20.5769.018; Sun, 30 Oct 2022 00:16:02 +0000 Date: Sat, 29 Oct 2022 17:15:55 -0700 From: Mike Kravetz To: Peter Xu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi , David Hildenbrand , Axel Rasmussen , Mina Almasry , Rik van Riel , Vlastimil Babka , Matthew Wilcox , Andrew Morton , Wei Chen , stable@vger.kernel.org Subject: Re: [PATCH v2] hugetlb: don't delete vma_lock in hugetlb MADV_DONTNEED processing Message-ID: References: <20221023025047.470646-1-mike.kravetz@oracle.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MW4PR03CA0354.namprd03.prod.outlook.com (2603:10b6:303:dc::29) To BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BY5PR10MB4196:EE_|DS7PR10MB5904:EE_ X-MS-Office365-Filtering-Correlation-Id: 6af8381d-973c-41e8-dfea-08daba0bedc8 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:BY5PR10MB4196.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230022)(7916004)(376002)(346002)(396003)(366004)(39860400002)(136003)(451199015)(66556008)(86362001)(186003)(6916009)(9686003)(316002)(41300700001)(54906003)(6512007)(8936002)(5660300002)(26005)(6506007)(44832011)(2906002)(66946007)(66476007)(4326008)(53546011)(6666004)(83380400001)(7416002)(478600001)(38100700002)(6486002)(33716001)(8676002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?396hMfIWetatqpuL3upx5gQeDh8UWO8Nohv9WrRoTyu7SUJv21LfvpPljdb/?= =?us-ascii?Q?oYGrsx6n1DxVunRGUxHAybNwD6LiGd98sNIEIMHSA34CxMe22687FI+5hqiS?= =?us-ascii?Q?4rcU6XJDBqydmbZnsMdXo0dvK0Or6nWTYYvmqMUlHDi8Nc+5RYEW6Uk/IJvu?= =?us-ascii?Q?BisuP+0OfCl8miuDkV9kaN+k2kxbpE+o6y6bG8dGY5V8vO7ZCS0z3ta0TOXz?= =?us-ascii?Q?HVINaSmfoI5W/rOKqUEcoGdjWc4DqCOe71UylUkW9zOzJGeOhVcdBgBfUgG4?= =?us-ascii?Q?yhMFUZ3aTzheO1jGp/2QEid7gxPL0P0X9quJTwhoGLDx5Dt22inEjrDYtrsQ?= =?us-ascii?Q?UvPLX/jeh4TwpM90LPBbd1+9fZD12nicbXU3dk6c5R0ey7Mw6/YbwkY7L2a8?= =?us-ascii?Q?PqBvH4Iyb48d+Xnd/lGCApvWkrBE/XnFNF5qYQ0aptd6i1ayB2rMc/xKNM4M?= =?us-ascii?Q?6gP5o8cAVqMOudtpfBvarIPkAk2uzRwTdIBx5dFxy1kXGelqAYsdKjOPFYkc?= =?us-ascii?Q?CEaL5Svh4cOnAms2gHbnoOCiCr3h9Rf088Y7d5nQh9k458S715DEdjXlNgY0?= =?us-ascii?Q?Sj5YTtpi8y6dkEo0MsNlr5MCQKGDfXlIBVvqop8+5A+4Q8CnBH5Y1U8t1XjN?= =?us-ascii?Q?5YJbJNPMNGeKN68sLM38HVX4sLIXnSX9yZXjewpF+F8dD+u9k5+KhqGy/TKU?= =?us-ascii?Q?74Vd1GndGSBGdWSgMK7Gr4NVM50vkBz6OfLFqvqRWpVLQ08zPkPw9TOC9RRA?= =?us-ascii?Q?qn1fY1GxOuci2V0/M/8HUgi3Oy0zB8/gTO+gRohuquu7zs0gGm6i7NAzqigp?= =?us-ascii?Q?1G4PMVXdZB/pJSQ6oiz72Wq0Q9gw7RGP59GW22boykvJSo6XLBXlV3SPIWOG?= =?us-ascii?Q?jazlGRCl9DdNIAAJZNmU2H7wICqM4UbS87Swx5zoE68GEQxuUhU1OzkIncVB?= =?us-ascii?Q?Icx/45yj+ZMW4NUhVhhJNVboh3dCjYtvgaoqJRgp7KHiQWtAbzSy/BTdvTUb?= =?us-ascii?Q?DIqDpwtWzo0H93ZOWJrsd3dC+G9c2MGS0Du7vQteg9LSh7ibrjifwpkEikmm?= =?us-ascii?Q?TfGREjKTA36EeolAEnPLF8rNvWS1sFuOYG+C7G/3SoN9f2T8A1F9ptgGfrY6?= =?us-ascii?Q?qkb5Y5c9+g5rlyoTLAEoTF0M+gedJejKhJWzCzrcvlPQJR8V7Oa88vkA8JNS?= =?us-ascii?Q?ycNMXubycEm6CYA/tE03USJcFasHj0AiYMCVClt2e6jDFI3ENfHH10BEFDdH?= =?us-ascii?Q?Z61Woeartu7k4U2anhQNtwyldTerHlCjun2lX9k9zciv/Ynhohl0ZhohDiiT?= =?us-ascii?Q?ReXOrX/f/iYMzHJSp92B9kfrLih7oZp0ou0nSs2gg243qWhMrZbdaUwaZU74?= =?us-ascii?Q?vXnPHq/e9ONA19o0ZA21+QKUPjxLrxbCuo+lTRKhdYttHzpXPOPz+Jd/gLu9?= =?us-ascii?Q?m7SL5o8YgkUwDBekAv2HMPPKSOhbojnMCttWQKJa6wsCfMzSv3CRouBZf9O4?= =?us-ascii?Q?ae8eohq62Int5RSLDQQnITifz5M8+J2PVCoroixTlM3QUR9y7/J5U/nPAe6A?= =?us-ascii?Q?l4D4oEV3tsIKdlxgcN7r04MSUD2GjOtUHHjqJhcrjwOY6AaGtRqjs6PSfyql?= =?us-ascii?Q?pA=3D=3D?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6af8381d-973c-41e8-dfea-08daba0bedc8 X-MS-Exchange-CrossTenant-AuthSource: BY5PR10MB4196.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Oct 2022 00:16:02.6867 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: LcS2YbG252+RyW08471ff5/pHBTEbMIfyvs2yMQhyjy5PWb5HnUtGL5U3+3zYc35+7B7Gh8F28aHOAuA3MUUvw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR10MB5904 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-29_15,2022-10-27_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 mlxscore=0 suspectscore=0 malwarescore=0 spamscore=0 adultscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000 definitions=main-2210290175 X-Proofpoint-GUID: XwaT0TVSStWJ7d_iPC6_tiCXTd9yktja X-Proofpoint-ORIG-GUID: XwaT0TVSStWJ7d_iPC6_tiCXTd9yktja ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1667088980; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=tPsYwScA75zcoPjU6ZQCZx2s7XqRblCuzFqWsG+amoM=; b=OQapkSmEKE+2/JOwY2lFwJnjOqdeJabzbzguVGo7UE1IG2Q6jGZ3fOWfQB4e2+M4IhCzuP 4+I7LyfOq7gRtSyC9KqzwUDNkggT1jUMKgb6cUAr76iaYnDoSUoCtx0dhuZ7nbCEy851Ir xMUJAe6JZChA2iEAUqFrIrc/QjwZDw8= ARC-Authentication-Results: i=2; imf14.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2022-7-12 header.b=oaWeDHFx; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b="OG1/Kom1"; arc=pass ("microsoft.com:s=arcselector9901:i=1"); spf=pass (imf14.hostedemail.com: domain of mike.kravetz@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=mike.kravetz@oracle.com; dmarc=pass (policy=none) header.from=oracle.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1667088980; a=rsa-sha256; cv=pass; b=LcCJCF+fhg+9BP2paNAcZ2+mCWyYVRiOWZRgTW810mvWOB1D7+GwM3AvTIxGJRWKuXPrqJ E1xTFc2y22hTPhVB+jQjjypa80rh3XZW2gQTRCO35bwkIwNaN3LONc1/sHw3Vy2whlkHMx 73LpyNgIfG8Kj7o5uiNrEEbb1ZLxlZQ= X-Stat-Signature: 7qariyircdrfq64qzgd8d965p4wxzxcz X-Rspamd-Queue-Id: 5360B10000A X-Rspam-User: Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2022-7-12 header.b=oaWeDHFx; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b="OG1/Kom1"; arc=pass ("microsoft.com:s=arcselector9901:i=1"); spf=pass (imf14.hostedemail.com: domain of mike.kravetz@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=mike.kravetz@oracle.com; dmarc=pass (policy=none) header.from=oracle.com X-Rspamd-Server: rspam04 X-HE-Tag: 1667088980-545838 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 10/28/22 19:20, Peter Xu wrote: > On Fri, Oct 28, 2022 at 02:17:01PM -0700, Mike Kravetz wrote: > > On 10/28/22 12:13, Peter Xu wrote: > > > On Fri, Oct 28, 2022 at 08:23:25AM -0700, Mike Kravetz wrote: > > > > On 10/26/22 21:12, Peter Xu wrote: > > > > > On Wed, Oct 26, 2022 at 04:54:01PM -0700, Mike Kravetz wrote: > > > > > > On 10/26/22 17:42, Peter Xu wrote: > > > > diff --git a/mm/madvise.c b/mm/madvise.c > > > > index c7105ec6d08c..d8b4d7e56939 100644 > > > > --- a/mm/madvise.c > > > > +++ b/mm/madvise.c > > > > @@ -790,7 +790,10 @@ static int madvise_free_single_vma(struct vm_area_struct *vma, > > > > static long madvise_dontneed_single_vma(struct vm_area_struct *vma, > > > > unsigned long start, unsigned long end) > > > > { > > > > - zap_page_range(vma, start, end - start); > > > > + if (!is_vm_hugetlb_page(vma)) > > > > + zap_page_range(vma, start, end - start); > > > > + else > > > > + clear_hugetlb_page_range(vma, start, end); > > > > > > With the new ZAP_FLAG_UNMAP flag, clear_hugetlb_page_range() can be dropped > > > completely? As zap_page_range() won't be with ZAP_FLAG_UNMAP so we can > > > identify things? > > > > > > IIUC that's the major reason why I thought the zap flag could be helpful.. > > > > Argh. I went to drop clear_hugetlb_page_range() but there is one issue. > > In zap_page_range() the MMU_NOTIFY_CLEAR notifier is certainly called. > > However, we really need to have a 'adjust_range_if_pmd_sharing_possible' > > call in there because the 'range' may be part of a shared pmd. :( > > > > I think we need to either have a separate routine like clear_hugetlb_page_range > > that sets up the appropriate range, or special case hugetlb in zap_page_range. > > What do you think? > > I think clear_hugetlb_page_range is the least bad of the two options. > > How about special case hugetlb as you mentioned? If I'm not wrong, it > should be 3 lines change: > > ---8<--- > diff --git a/mm/memory.c b/mm/memory.c > index c5599a9279b1..0a1632e44571 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -1706,11 +1706,13 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long start, > lru_add_drain(); > mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm, > start, start + size); > + if (is_vm_hugetlb_page(vma)) > + adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); > tlb_gather_mmu(&tlb, vma->vm_mm); > update_hiwater_rss(vma->vm_mm); > mmu_notifier_invalidate_range_start(&range); > do { > - unmap_single_vma(&tlb, vma, start, range.end, NULL); > + unmap_single_vma(&tlb, vma, start, start + size, NULL); > } while ((vma = mas_find(&mas, end - 1)) != NULL); > mmu_notifier_invalidate_range_end(&range); > tlb_finish_mmu(&tlb); > ---8<--- > > As zap_page_range() is already vma-oriented anyway. But maybe I missed > something important? zap_page_range is a bit confusing. It appears that the passed range can span multiple vmas. Otherwise, there would be no do while loop. Yet, there is only one mmu_notifier_range_init call specifying the passed vma. It appears all callers pass a range entirely within a single vma. The modifications above would work for a range within a single vma. However, things would be more complicated if the range can indeed span multiple vmas. For multiple vmas, we would need to check the first and last vmas for pmd sharing. Anyone know more about this seeming confusing behavior? Perhaps, range spanning multiple vmas was left over earlier code? -- Mike Kravetz