From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6F4E81C3C11; Mon, 8 Sep 2025 20:57:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.165.32 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757365022; cv=fail; b=QidQrR3TmBIGa3t33T+4u7gYyfrxln+0+j5csudAJ218hyF1m/8RiAuu9GwxXydKcGU7nazvciNDl7o9kK3ftZwX/W5+7opOIz6JowI5FFTXYhicslOvakVJaG5lpdG5UJ7URPfVhcTDGKbcINlbj+kgaSOqL67PeFqF6iKXjs4= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757365022; c=relaxed/simple; bh=WjCPZiBfnf7U0jWxCn88RqUVCWM1IOr8OrA64bzyILo=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=Q2Kd7F0hPlK0lP7Ap8j2lLsjkkoGIS1fr42XqcdK+JCAZpDLy81Eyf6oCUqNl5uaEbA6YY23jL1oUXSVBx7OdTNSNdmFsT9/8QeKjXKe4UMTPP9+OJdo7XPyBATDgDvO1FOkKvhGG2ydjHB1uIK2/iHXKvyQfoskS1xG03s+3DY= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=JWdKhRh4; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=rXmmnpPL; arc=fail smtp.client-ip=205.220.165.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="JWdKhRh4"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="rXmmnpPL" Received: from pps.filterd (m0246629.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 588Ktlco021275; Mon, 8 Sep 2025 20:55:48 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s= corp-2025-04-25; bh=QMvtNVJ4Gep9T/m4bXl8OVS8azJ1Llgl8TWelwxnpwY=; b= JWdKhRh4dFS154Lo+h89raa09kK8K4HkAXR7DnvpF4la4sXK4FloXhdUzkTBs4xl kmeeMFSobqpY3lB9VwRjkIUm0aZ3r9a6vlqD9VuxsQNavsdR+FO+2+Cl94ctBkGT xAgmGGE8CIX+qsLR7rWYTp0wwTLeWIszecKM/ciKaKOaSEo2XBZ+UxJ34oX+RQyl 0KJ2ef9URCLBffp4OIHCEU4L6E133cW69X8GZQezZ/Aybo7QafBtN3MHfqTa/bde 19dSIbVjPKIj9O2fEIcwc6+Wh+BZaToDh5/N0R4tTvpY/vt7CaapzAfjkaiSR79C BJK1e8KhU/5mc1gqgg2C3Q== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 4921pe8mq0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 08 Sep 2025 20:55:48 +0000 (GMT) Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 588KPLst002889; Mon, 8 Sep 2025 20:55:46 GMT Received: from nam10-bn7-obe.outbound.protection.outlook.com (mail-bn7nam10on2052.outbound.protection.outlook.com [40.107.92.52]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 490bdf7syc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 08 Sep 2025 20:55:46 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=GAc1vxaMPO/36jPV44fOVPIXPvYcklLWh7oy/6luoSLLQUAsS5iJP8lAlrTh3n5GQAeov7CmHhMsLoy+3ARtK5Janmix0LHUcizernTSsC4jt/3NFHJzlSabDCCMPoMjTmMF1s9OIhnYK2ugo84Em56LV6PMStD/49YmMxy/EW9xCklcvK0UXxAsfpdknndEmt9p97hXqjHQ+TBzI8YqTZnRCe4zNDGJdebslig2KRLLp++OWjmxF1typRx/i7ddHjUmr92eXP3K0kC414Q6S+Qn0chbtg1fRH7DC6Q5wvNS0nLVroyqY5wpSbnFjRIAN5yF45gyXIwXA7pvzis0mA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=QMvtNVJ4Gep9T/m4bXl8OVS8azJ1Llgl8TWelwxnpwY=; b=A0h2ntjC/HR9I5aTp0/5lsm5+1gDNYHWs2lua/k+JvoCEoY6CvdO7DkAsWq4u2dGtEwi1/N67CSw5wmkKZQshOr0266kBImXQU7smnTi2l7yn3HYFHFiR0jx3DWu4uLks/mlcEj38x+HWWbayBGDthVO0cIjrNcqYQTfAL8cPE1PfLkO8Gu+zMwb4N50TXVkgtmBi0x+BgdVSsAAJ1V8hbTnGC+sCKgcodhbxHPUi7HFj0zMBI8TKHZJ4ufjezL2C6vNR1FONZiwFvPXTtavmrbtxqVwmvi1QPiiABWz6aZmosGz1siYVpAAZvs2Set2hLzN4Hkb1v4JxzFc/wXHeg== 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=QMvtNVJ4Gep9T/m4bXl8OVS8azJ1Llgl8TWelwxnpwY=; b=rXmmnpPLveoW6uEdBsdWUkZjgAYTQUjZ7KQa36ZAYES+YxsM2HqJCWD+020vWkaOKj4N9ZGNb+82UGcVmZm9TJ7kRrEexjfVNAozgtz1RsLDSZ37a3SuMG67+B+XLHNiMw7ClGoICPsX5ClNErHalLYcLoYQx2bOILQMqJP0f08= Received: from MW6PR10MB7660.namprd10.prod.outlook.com (2603:10b6:303:24b::12) by BL4PR10MB8231.namprd10.prod.outlook.com (2603:10b6:208:4e6::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9094.22; Mon, 8 Sep 2025 20:55:38 +0000 Received: from MW6PR10MB7660.namprd10.prod.outlook.com ([fe80::41fa:92d3:28b9:2a15]) by MW6PR10MB7660.namprd10.prod.outlook.com ([fe80::41fa:92d3:28b9:2a15%5]) with mapi id 15.20.9094.021; Mon, 8 Sep 2025 20:55:38 +0000 Message-ID: <74410776-0e8a-464c-b725-9780a0400afb@oracle.com> Date: Mon, 8 Sep 2025 13:55:33 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 22/22] mm/mshare: charge fault handling allocations to the mshare owner To: David Hildenbrand , linux-mm@kvack.org Cc: akpm@linux-foundation.org, andreyknvl@gmail.com, arnd@arndb.de, bp@alien8.de, brauner@kernel.org, bsegall@google.com, corbet@lwn.net, dave.hansen@linux.intel.com, dietmar.eggemann@arm.com, ebiederm@xmission.com, hpa@zytor.com, jakub.wartak@mailbox.org, jannh@google.com, juri.lelli@redhat.com, khalid@kernel.org, liam.howlett@oracle.com, linyongting@bytedance.com, lorenzo.stoakes@oracle.com, luto@kernel.org, markhemm@googlemail.com, maz@kernel.org, mhiramat@kernel.org, mgorman@suse.de, mhocko@suse.com, mingo@redhat.com, muchun.song@linux.dev, neilb@suse.de, osalvador@suse.de, pcc@google.com, peterz@infradead.org, pfalcato@suse.de, rostedt@goodmis.org, rppt@kernel.org, shakeel.butt@linux.dev, surenb@google.com, tglx@linutronix.de, vasily.averin@linux.dev, vbabka@suse.cz, vincent.guittot@linaro.org, viro@zeniv.linux.org.uk, vschneid@redhat.com, willy@infradead.org, x86@kernel.org, xhao@linux.alibaba.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org References: <20250820010415.699353-1-anthony.yznaga@oracle.com> <20250820010415.699353-23-anthony.yznaga@oracle.com> <3752d094-e754-4453-b404-75d92de3e364@oracle.com> Content-Language: en-US From: Anthony Yznaga In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BYAPR21CA0005.namprd21.prod.outlook.com (2603:10b6:a03:114::15) To MW6PR10MB7660.namprd10.prod.outlook.com (2603:10b6:303:24b::12) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MW6PR10MB7660:EE_|BL4PR10MB8231:EE_ X-MS-Office365-Filtering-Correlation-Id: 964e9e8f-7ced-4d2d-526a-08ddef1a1076 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?NGQwTWtUeDZvN1gyQUFpQ21ZVkxLQjNRSmRBejNwMGVhTFdKaWpQNm4remVV?= =?utf-8?B?a05yTXlmSGRseElrRDYzZUIxV21nV0xXcWpoRVZZTmVFY05TdGh1OWNBQ3Fy?= =?utf-8?B?OXJqNnZ2cUM0aXkwYmsxanFVd3pSY2RBOUd3eHpUL2tya1d1aC9MMUV5dzFE?= =?utf-8?B?ZWNoNU5QUE1iZGpXMlgveXpJN3BrelVBczBxOHdEQUdWemlMQklia2VmckRO?= =?utf-8?B?SmFDOExSLzIvQ2NKWjBzSzJ2cmVsRlFYVFhWL2V5ZTNLS1A4Nm04QjdVZU9s?= =?utf-8?B?ZWcvRTdMWWhiRlVwS3ljd2RldS85V2tPcERWZUxOU1l5QmJkNjVSb0ZYcWRU?= =?utf-8?B?RGlBRFBZeHdjVmtNRXN5VkJ2TCtKM1dLa2ZJYWNEL1dkeUpEZEZjVWtaWTdh?= =?utf-8?B?ZEhrK2h6M0orcGZJRi9YVUVrcjhRRkVyelpUT0R1MDY2eXN0RmVXbnVLa3N0?= =?utf-8?B?VW5kdnlZM0JYNXdsUWtzWUllM0NXSlVLNmg3OEhKL3hMb2V6VVM5Z0d1RnpV?= =?utf-8?B?QUwwSEdQOXE5Q2FGSmJCenh2bldVN2pYV1RqU3FqcDRrOWZEclR6OGJPYk15?= =?utf-8?B?blljVTBkQmp3YXdnZHIvVkgwSmNLaFFDTXF1VDRvR2M1dkJDL1g5Wjdzcjlp?= =?utf-8?B?alB6SGgyVzdoVXZ1ODhPa2tZYUZIYXQ4a0RTZ3IySDQyZ2taNWVaOCtFVy8z?= =?utf-8?B?TnhwdXU4OXNMd1ljYUp1STBqTnd0aTFOSERnaXNKdWdxT0dZRk9FYTlXeVRZ?= =?utf-8?B?c2RwNnZ5Y0EvV0x5UmQxbG5hWmxYR2ticHdJeG5aVVIzVldjYzZxdW1BUEs5?= =?utf-8?B?cVFaZ2dmblQxcHQ5TE9lS003ZGRocVRxV1paN0V5TS9sSGZaV2FnUEEwcm5N?= =?utf-8?B?WW1nOFdMTGt5WkthMlYrUVNnVGI5bUc3T21RRExzV2w4SERPM2FhU3FNUFFG?= =?utf-8?B?MXE4bkdJWFlzZExYbzIyZWtpeFo0RkEyMmMrYmRiY05oU1JILzNRQmE4N2FI?= =?utf-8?B?YlhBd3IzY3VyZ3pLNk1BMlJRTXNLQ29sYmVkMFllMlY0VlhkVnVIM2x0a2JO?= =?utf-8?B?cjNNcVNzQmVWRWNDOGlPWExvTldBQWhoMUtyc0tWTlFkTW9CMlBZMVVXZWpn?= =?utf-8?B?dE1aL0FNVXl0Y3J6WWE0NEpJZDgzYVY2dFkyV09Sc29vSEI3eFBwVU9TeE0r?= =?utf-8?B?Z1ZNQkNMNFdXVWYxdk03aHVrWUZCcTYrVk5HeDN5V3FWdGZRWStpUU5kTFh4?= =?utf-8?B?ckFZbElHa1k2QkhCUGVsR3FxNVA1ZmM1MkZTalQ4WXByYmNIY0QyVjVoT0hx?= =?utf-8?B?ZW9ua2l5RitEQUtHbUFuZDV6YkZleW1GcFRscndZMkZac1Q5d1J6TWU4UVkw?= =?utf-8?B?cHpSdjJYRFBWak8vL3VpSW5ocHFEb05hNnpMTnFoTHd0Uk5TQnd3ZU4wNno1?= =?utf-8?B?SXBpdnJqMEFzS3F2dzZITjVYRHdOMGZJSUJrd2xSNlBPSkt5TFlsbFl4azZD?= =?utf-8?B?aTM4b293OE1EOUJmTUJHMzJBL0JFL1l3NEFBdzZndDJ2ZzJkUHRzQnRxTjRG?= =?utf-8?B?SmVreUhGQXMvM0RyRyt0SXZIT0J5eUZrVGdQN0l5QUovMDkvK0FBSWlRTVRW?= =?utf-8?B?S1ZrQWpaTnhSYXY1MDFXT3NLQlVTMmZDSlJaUWpGT214cEtrZ0tqY3JnWWNY?= =?utf-8?B?aENPNkd3ZGRxRE5OMGF0cFB4M1MzdWtmMU0vZ2pkbjlpRWRZZTQremh2R1pu?= =?utf-8?B?Q0VXd3k1bU90WXB4ZG9ydnJUS2ViejNzVVJvQVVKSFdkZHdsMTJRWHc1NWlr?= =?utf-8?B?UHJ3NndXQUFlY0tHdmFqTEFEck94cXNQQW1ISUlTempLNHNtOURaRzdaNG8z?= =?utf-8?B?U0NaazIvVWdLV1lBckxHT3RYM3ZTMnNtNWgzb1lqditPTUdsZVpqOGJvaHR0?= =?utf-8?Q?KJcpsAI7gew=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:MW6PR10MB7660.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?VUxuRFpDbGVZZ205V2Z2aGF3bnQ5RzcvVjZ6czFqRWYyZ3RxZjZvcmNBRy9t?= =?utf-8?B?bjk0YTlrRHVvdHQ5dE5Gekh6aEpxUGFLcXZ3azlvM0tPd3FqQitPV3Q0ZHVk?= =?utf-8?B?TmJ3VEw0a0dRbG0zSXJ1ZXJCUjhOUHI0a3NRejZpZVRSVkZYbmdHRXJ1STdk?= =?utf-8?B?dDV3ZHplTGNwK0YzbHh5VE5Yek5YMjdSNVpWNElFdUtBVDZxbi8rNWZCajFr?= =?utf-8?B?SDB2cmZaWEJkSjIwMGRFMGswK2plS0pBMXI0LzZpdjVxaEpxNGxmazN5NzNp?= =?utf-8?B?VU9Wdk5Pc0JKQ21CSW1EQW5KSC9yNURxdlpBdWFvK09vVVBCNW5qRnorckVq?= =?utf-8?B?V2FNdmhUb3ZYYnM4bUZML0tOSEhyd1BIbjVHWitSS2tFVXNjN2FlV1NDL08y?= =?utf-8?B?c0F3NTJGYThpN0YxRHNLOUpYVDZDbmRZSkxBSVh4RjRpMXZ0NTFJUnFKcEd5?= =?utf-8?B?Z1hsTmlsbHJzVnNkcHRUTTVidDZLOXAyc1RadDFvN1plQVArN1BDYU9Ya09y?= =?utf-8?B?dmJBOFN1bnNlT0VnVDhaNXBYYXBEQ2h4WnZWR24zTFRydDBRWmlqVHZ0RFVV?= =?utf-8?B?WTRNNW1YUFJxQk5Ycmw1dENFUFRnZVV5NFdoN1FjL0phaUFUcmlzTlk4dzZ4?= =?utf-8?B?UHVuUmV6Sm92cUM5YkVFY2IyT1psUzUwRXdFb0xiWHFDMjRZaEZsdEhpQ0N5?= =?utf-8?B?MTFNSFhueDlDMXlTQ1JnNm12S2NZL28rU0dCSkJoeGNDZFlGQkNFV1YyUjJZ?= =?utf-8?B?Wmo5bXc4dGdsazJ2cXhRb1llZThQK0JCeHZoQStocjh6WC8wZlRDak53VEhF?= =?utf-8?B?b0pSUWxmOFpvRGpkSVZBT2JUL1R4UTh3Z2ZYejVLNHZQSGdpUXNKMTJCcGFo?= =?utf-8?B?VVdZdHp4MFZ6eDlaOCtvUmJrd3JEbG9rbHZ1NEE2bmZSMTRQUlhmM3h0Z0Nz?= =?utf-8?B?UHovRmcxUlZvVUxTenNPNWh6d3lTd0JiMWVFT1ltclVjVytKemJwWmVpNmJZ?= =?utf-8?B?bTd6SlZUN2tZKzd0QTZ0UGgxeGt1bXpHOXY1ZjJBTExEbzZyN24yUll4TUlR?= =?utf-8?B?Wkhrc1FBTmI0emp3T0syREFnZCthbDVURm53R1UyaVN3cWtSdUFyQTM4OXBL?= =?utf-8?B?R0EvZDhhNHJ1L3RBQUlIV2VPcUUwQ29UVVNNMngrUmpqdlZNL29HVXJJZXRC?= =?utf-8?B?dWgwRzd4bTV1N0J6RDcycnZ6YUpTOFJrN2lQUVNzT2JIZXVJbUlNdFlwNTZX?= =?utf-8?B?ZDBQMkd1d3B1VDFNZHN6YmwwRGx3U29aR2wveXMwWUxWSWxjUUcvR3NhMG5m?= =?utf-8?B?R0tvUVF5bjhRdmtPSmJBQWl0UGFaL2V6enUyOWhGSmpSR1RML1VleHdFQ0JC?= =?utf-8?B?a0NWVGpLLytoUTRiY043bDRFcytLRjRNK3Y3SU5XSnFWVWl5ZlVVWHQ3Y1lx?= =?utf-8?B?WFJHRTBId1Y1aWpsWm9PWEZVbkVXSS9ldmlZRlV4anAyYlpOOVdHSndSdThW?= =?utf-8?B?SDhYZG9ldHVjY1p1OFZvZ3M2TXdTMVRMVGdHaVg5cUFWMlN0MXhqK0lNSnRV?= =?utf-8?B?ZnBWY3pwS29sOUdJM05JSzYrbFBsZXl6MGNxenY4aVB2NHZhSFZOTFdrNzVw?= =?utf-8?B?L29Ibm91cE1NMTNjRjNFd0NBSytJckkrdTZOTDkydzd4Vk1FRXZKZ2JjSmNC?= =?utf-8?B?SU5QZmhwSzYyeW45ZkdJdFkwbFdiUndTMUNMdy82WFVGZDFxSDBDYVNNR21i?= =?utf-8?B?Rld0aFkrU2x5R1ZqNEJiVmVmMUpFZHRMT3gzUXh3cmZ0bnNuS09vcWcrOTVO?= =?utf-8?B?dEk3TWlJV0xyLzRrVHY1em1Va1RDWlZFUkI5eWdWZld1TE52bFFMWUFNTW04?= =?utf-8?B?QUEvcTc3TEtMVnM4TmVFeG5hTHdCdjhKT1BpWkNPVUxDUmVzUmh2c0JpS3Y4?= =?utf-8?B?eTdGK0tjL1dCeDJTQXF2enhlMHVxekZCcnlVYXk5aTBpRTdiUGFLOFZleGYv?= =?utf-8?B?S1c1NTI1ZThEY3BZcmo0d21VY3BUa09HQ0t6NUFjZGFWa2FQbDhNeXE2a2Vw?= =?utf-8?B?cnRxeStVanQ2K2cvNnE4QXJBOHJyRHA2SFU0QW1uQ2lRaDFadVo4aGI4TGVP?= =?utf-8?B?VEQrWForazVMci9CYnJ1OEhCZGFIQ2tuaUIwK2NQV1VJZkl2RGhvTmIxU0VV?= =?utf-8?B?bnc9PQ==?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 964e9e8f-7ced-4d2d-526a-08ddef1a1076 X-MS-Exchange-CrossTenant-AuthSource: MW6PR10MB7660.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Sep 2025 20:55:38.3293 (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: XxxXGqGVM5jbYqx/fKqZmlX/cAhH46oujqICdGmqyyjwZzNVnhg7Rd/vmZPNfrSiZEk4dn7fj4waPFMTRTTTkST5VLjt9dMh3vgYNDnKE4A= X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL4PR10MB8231 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1117,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-09-08_06,2025-09-08_02,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 adultscore=0 suspectscore=0 bulkscore=0 mlxscore=0 mlxlogscore=999 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2508110000 definitions=main-2509080206 X-Proofpoint-GUID: b5HgO8gE4FPcqHeqpvpTBovd2v3tZF10 X-Proofpoint-ORIG-GUID: b5HgO8gE4FPcqHeqpvpTBovd2v3tZF10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwOTA4MDE1MiBTYWx0ZWRfX38PyNRWCkZCj 4o+Zvi5+ntjuJgyUNerBzEqKDA8TQx0QChYSS6YVjv50fWT3r1FjcTzm1GP3/v+x9qVBl2lXPtd EntEFxSFB0kekWnwaEpyo4VXcVQSU44XC0SLE92TTXHlyJGJ5thzbgJ6Tk/V5pCMl7rxK9YtD0n Q13Z39z5pSFDilb4maYx66lDwTOYEkDXh3jaHvxCnVVDCj2f0Mp1Dwhd4v9mF9/6litt6LGiBgf pZ7jvqkNdFArnwpRV33qrTXep3RXJBCx/HwglLNu1Lf9K8WuGAGniJzpFbjok8lQjvC6p4Qgg5D dQ2LNRFaIqMrk6MTyAmortLqzh2IG4jw1+VasBaVohHUE/vh3I2FlE/DC37ap9hQHaRrjnixy2y nwInziScL9MM5Agsdiw3mdoLswLe7Q== X-Authority-Analysis: v=2.4 cv=b9Oy4sGx c=1 sm=1 tr=0 ts=68bf42d4 b=1 cx=c_pps a=qoll8+KPOyaMroiJ2sR5sw==:117 a=qoll8+KPOyaMroiJ2sR5sw==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=wKuvFiaSGQ0qltdbU6+NXLB8nM8=:19 a=Ol13hO9ccFRV9qXi2t6ftBPywas=:19 a=xqWC_Br6kY4A:10 a=IkcTkHD0fZMA:10 a=yJojWOMRYYMA:10 a=GoEa3M9JfhUA:10 a=gvk5xnXEtd-PH1V_gY4A:9 a=QEXdDO2ut3YA:10 cc=ntf awl=host:12084 On 9/8/25 1:28 PM, David Hildenbrand wrote: > On 08.09.25 21:21, Anthony Yznaga wrote: >> >> >> On 9/8/25 11:50 AM, David Hildenbrand wrote: >>> On 20.08.25 03:04, Anthony Yznaga wrote: >>>> When handling a fault in an mshare range, redirect charges for page >>>> tables and other allocations to the mshare owner rather than the >>>> current task. >>>> >>> >>> That looks rather weird. I would have thought there would be an easy way >>> to query the mshare owner for a given mshare mapping, and if the current >>> MM corresponds to that owner you know that you are running in the owner >>> context. >>> >>> Of course, we could have a helper like is_mshare_owner(mapping, current) >>> or sth like that. >>> >> >> I'm not quite following you. Charges for newly faulted pages will be >> automatically directed to the mshare owner because the mshare mm will >> have its mm_owner field pointing to the owner. On the other hand, >> allocations for page table pages are handled differently. >> GFP_PGTABLE_USER causes the accounting to go through >> __memcg_kmem_charge_page() which will charge them to the memcg for the >> current task unless unless current->active_memcg is set to point to >> another memcg. > > As a note, I think at some point we discussed re-routing page faults to > the owner, so the owner can take care of all of that naturally. Is that > what's happening here? The memcg charges are routed to the owner but otherwise the page faults are handled using the mshare mm. > > > So, are we running into that code that we have current be another MM > than vma->vm_mm? That will always be the case when handling a page fault in an mshare region. The fault handling code uses the msharefs VMA to find the actual VMA associated with the mshare mm. The actual VMA has its vm_mm pointing to the mshare mm, and it is the VMA passed to handle_mm_fault(). > > Reminds me of: FOLL_REMOTE->FAULT_FLAG_REMOTE. But I guess, we don't > take care of different accounting in that case. > > Anyhow, what I meant is that you could just check whether you have a > mshare VMA, and if so check if current is different to the mshare MM > owner. So I don't immediately see why MMF_MSHARE is required. It's because it is not the msharefs VMA that is passed to handle_mm_fault(). At one point I did have the code for setting active_memcg in do_user_addr_fault(), but it did not seem as clean. The msharefs VMA is not passed handle_mm_fault() because protection checks done in the arch-specific handling need to be done against the actual VMA.