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 04ED022A4E8; Thu, 8 Jan 2026 17:20:17 +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=1767892819; cv=fail; b=lH+m/nXyqwbPPDu2dhfdhRKz4k/O4cXQa+clWKl6Fa1ormvccRvMdKynXIN3SuEVpxPdf6Rf5k7FKwHvZRxiYlIxk+cQF+BPzxE+DyIx21xhgZ/S5gy9T7s6WtcmPbZqWmQWOUdX3zEWe0Oqt7tfVCD+bLdp+K7DwuFTdiQvwkQ= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767892819; c=relaxed/simple; bh=GXgxyS7dsic4h914q+I5br4n4pKRenp9HPTSairPq3I=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=e2IcVFqKYUhskxPIistQcLEdrxZXGMqjl8J+B0aASxk7m5F+AX8VfVUcPZgIduSWC1E3dntqHkplIqIRjTuqqB4+fPXNrRIMYRpdXSH1V3Hg4HwZr4yJEQop4YmZlWkMIA684OY+oLy1AHf9rvIvcYuVB03lGhjK8KauG/iqSL0= 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=KSz3NtMh; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=oFCRDQxW; 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="KSz3NtMh"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="oFCRDQxW" Received: from pps.filterd (m0333521.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 608GtSnq984549; Thu, 8 Jan 2026 17:19:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2025-04-25; bh=RcMgDSe29BQUkAVz+n IbUeO664MT21WBeBhkXa9QDCg=; b=KSz3NtMhhchPIoD46EucSDrG3bTaLxACoJ V89n5eQyk2ayfu240tvuoA3sG6WnzmYs8/iK8Y5cjWoJQL4AZsbjPsSYge7mzyx9 5WdFB/yR/u/I8VJGO2lTYsl9JkWAiDR5t9SV8Ut+8DjIoKDupB3h63ZYE1JMXepH m7qkg73lnl0hMZR+HYbbQshlGfhZQi4KgxQ313x3V/phRKpLjDbQhWTpxIvZnAZj 1LBwNLFfqbcxyjuFA3o9aW1GMUZmEtGOhm2CSG9rFozBojq+H5HuxRfvOErfOWiq dZyk1781mmPVbCf41ad3thrNoLsU5z8GNU9VxA7jB+Kq03Vq01IA== Received: from iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta01.appoci.oracle.com [130.35.100.223]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 4bjgh6r19k-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 08 Jan 2026 17:19:13 +0000 (GMT) Received: from pps.filterd (iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 608H7JEL020382; Thu, 8 Jan 2026 17:19:11 GMT Received: from sa9pr02cu001.outbound.protection.outlook.com (mail-southcentralusazon11013009.outbound.protection.outlook.com [40.93.196.9]) by iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 4besjnbrg8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 08 Jan 2026 17:19:11 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=XApnjfHKZlL3V3qT1M+P6ypWuxeZEGjSuqu8L5xtg9i5N09+C2CaH8OutQxPTFTr9Bx5We5Ye7N1jNtxgF4NM+HTpmamvTddORdKo3hop3H0As2xKU/7GrWcNLBmKK9kpedSzAW6ZtGF02rh4W3AS0CN8joJlqzDt2qWsAHQF7+VZc6DIxxdeUm01oVtnO382K9uhkHC8B7gYbSHZUr8KIPiNtqNr/DWbZVuoHVIV8Ad7IE/9zT6P4uGqN3dNN9VrDm2nzP8HTf1M+hucNsTahxC3QseRGtuoqAewEY+L6HKt5+AASedzpQTREKiSj2WAkbGK02OvXPga9tfnYnkDA== 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=RcMgDSe29BQUkAVz+nIbUeO664MT21WBeBhkXa9QDCg=; b=Rfc8cdE6GgqONgTVjzCuPLvXXVwp1ROc/vMKD/dsMXRETHCCRwMwbaDLkEPRIj2/36e8imURsHxruX4pxarbygnykwUIX1hEtpvtc/O3qO3JGJfGDFp8ctPjXzA2znDeQlJCAPpmb0rtuqHFkmn+DPqEOKxasGTF0U/ftnwa+/lNd63WowjOhYodfWKjhSoIu3xfYg1RIl1Gxs+esniWRolK4NQyCvzdcPh8gEKrwSByoX9OqB3OQryziHlXmRIUZgc7nrPsd9u/8o33c9zibEdBhrsLVRn8e03DGEnKXbnpVJocjlDGSeIFHY8yFAsKoQvCggzVjmz3+qPN+DoT1w== 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=RcMgDSe29BQUkAVz+nIbUeO664MT21WBeBhkXa9QDCg=; b=oFCRDQxWVGwdp04RONlra11GN0jePJJzlpOtD0WM1rccfzbznpMlihNudjAObX/yoW0kBvGeExnw2meWZe7tH5JHH3t6frzsJ4MRNohUjqgjV1TyrERs42E2fqNwLBFxgDDJ9IBl53wp0dxNv8XJ8EsXlLo7sNfljA3huqJ3xM8= Received: from DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) by SN7PR10MB6524.namprd10.prod.outlook.com (2603:10b6:806:2a7::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9499.2; Thu, 8 Jan 2026 17:19:05 +0000 Received: from DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::f3ea:674e:7f2e:b711]) by DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::f3ea:674e:7f2e:b711%6]) with mapi id 15.20.9499.002; Thu, 8 Jan 2026 17:19:05 +0000 Date: Thu, 8 Jan 2026 17:19:07 +0000 From: Lorenzo Stoakes To: Nico Pache Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, david@redhat.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, dev.jain@arm.com, corbet@lwn.net, rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, akpm@linux-foundation.org, baohua@kernel.org, willy@infradead.org, peterx@redhat.com, wangkefeng.wang@huawei.com, usamaarif642@gmail.com, sunnanyong@huawei.com, vishal.moola@gmail.com, thomas.hellstrom@linux.intel.com, yang@os.amperecomputing.com, kas@kernel.org, aarcange@redhat.com, raquini@redhat.com, anshuman.khandual@arm.com, catalin.marinas@arm.com, tiwai@suse.de, will@kernel.org, dave.hansen@linux.intel.com, jack@suse.cz, cl@gentwo.org, jglisse@google.com, surenb@google.com, zokeefe@google.com, hannes@cmpxchg.org, rientjes@google.com, mhocko@suse.com, rdunlap@infradead.org, hughd@google.com, richard.weiyang@gmail.com, lance.yang@linux.dev, vbabka@suse.cz, rppt@kernel.org, jannh@google.com, pfalcato@suse.de Subject: Re: [PATCH v13 mm-new 00/16] khugepaged: mTHP support Message-ID: References: <20251201174627.23295-1-npache@redhat.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251201174627.23295-1-npache@redhat.com> X-ClientProxiedBy: LO2P265CA0440.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:e::20) To DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM4PR10MB8218:EE_|SN7PR10MB6524:EE_ X-MS-Office365-Filtering-Correlation-Id: 4c5f2e77-6c4d-4747-a1cd-08de4eda066c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?JX66QBxUDkf2Nl0HQ/73Vr1IFTX8TiSn6gMKw9eByOf23m9TXwK4kaZGVZPH?= =?us-ascii?Q?m0HX3SxCOe2qAZwGHtpUejty3WUDXShlGRID97al1X/tHVkOv1TOqpQ8rSRC?= =?us-ascii?Q?4rCGESdDv7Rq1Jsa95M1ehY5sPYar4FeEellbwj3eNDfpLYdGML4Bgo0wG10?= =?us-ascii?Q?IsWdDESJiWY99+WgXJXaIFOOeuhgK9l9MvMxdcqaECrW64I7onRSkyngS682?= =?us-ascii?Q?7WcH3NgJBM+Ff7NBVzDCJNPCbvaQbEO550daiqgtwPYVCCJ7fCzMRo52cFFt?= =?us-ascii?Q?4xCZLWoBOYJ1+H12A/+RywLY2fojE2NuruKd3kTDk0UoEMzx10PlZlztuGog?= =?us-ascii?Q?yX7iZcMFBREhPkl8UPS0ixCFT6bBpNgEp+vDxH6kdCR2svwAj/KCG4tZ5wPp?= =?us-ascii?Q?ID+BapjY8Uy85cCLb203Ki5btAEE12iHlWEuCG5rNcQ47GTLzMpL+jTgzcnQ?= =?us-ascii?Q?ej/HWVL4RquRNG0HCnP0Q/JA6+QlCZEnQyZAyIGBe5zxwQ2D7wCzxBkXgLAB?= =?us-ascii?Q?O/+LJtpcJ8OmkZGy+ecsrVLDN779bYnTt7btDFP49abIGsqGLECgg5H7KlIA?= =?us-ascii?Q?L0kknJeLCvM2EF1e+v8bELzroxrSDuJXiak0bTnG+mHcm6KnczHIEpS8t5bF?= =?us-ascii?Q?nmVdNv4lYYvpIZ6GBoz45+4Sj3btNHGkoJ7z+6E8I/U8B+waSB6b7r7ptAy3?= =?us-ascii?Q?5IvMgTxbbReYoU23wIcNn6nMBs0D27dVqBoEyMj6hp1W6Cbb1319Vw5K8zrK?= =?us-ascii?Q?MbuSh/feSH4HHgvDfGylqZdtCESAI8kOA7GJNjPCmYLDOZzxc/UnG7vUgXSW?= =?us-ascii?Q?MmPNYuhAaJMyzCW+61sWlAffX/Y9k35HQ2rJ6kGTKRQ8Vol6udKkYpV5aEa6?= =?us-ascii?Q?V0Eo8FJJOYcIXMRYYaPJMnwzzyY+NvfGMueszXQAsTQOctrTsEo2Ufv/PZ1k?= =?us-ascii?Q?uPa6Edgf44tVaRK2Wkh5hWEJ1EOqpLaTD/C0AeRhxbgBzVMUEqWdlfmcx2MS?= =?us-ascii?Q?tdLa0W919fJrDDyTAwwYgow6bL3PYKnO24jOHgPOgnkM1IeCnko/YUSUlcYs?= =?us-ascii?Q?VZo+A5vCSqjIZRLBVvdwVXJzi2xzmv9L1tk1P5eKtxAUtzBZR2B7qcUAE/EN?= =?us-ascii?Q?L7Qkf0pugRgJEdvP/4THB0qPtLSekfBzYj6Wkg4ocKSM04aFcaCAXjattID3?= =?us-ascii?Q?giBvJjN89d/UxriczQTFgiSM5GYlHZJxUW9Qae95s/bFbIZ6DuzeriMXOPmc?= =?us-ascii?Q?L4m+2un4kClY+lSP12lJ7N52+rqe3bCLa39TK5Gz7xYrp6tb82Xn6zh/yz68?= =?us-ascii?Q?W/HbnP25Bn2SW9Y37zI2M4p+q3b//Wu+3CIhjgf4VZw3rZ0i0ETzYJ4JJwBQ?= =?us-ascii?Q?OM4mc9N3FwZ/kvG08g523cdxOJfT0LnbgTuuiS6X8ivja8zWDOJxG6p/ahaV?= =?us-ascii?Q?oqHcmJQSs4NhLPas5Z/BrmWqTZPeddmNPIsfoRxaAo2Qzf8fcypdkg=3D=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM4PR10MB8218.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?vKY7/k+r0tZr/0elM5rzT3wI6mGMw7mqk2ahymWA4i+/BFTjkTmOaDKXIbUD?= =?us-ascii?Q?FqTMFaTdHBadObZ+vT6hewZk+rAlgUmKQpwRoq3EGAT44bfJJRWrxpfZLywI?= =?us-ascii?Q?ZePA6r9wvvb1hM6elMYPB5abZEXYxKy8wZCdbcUsuvJKRSVLSKSZNunoUtwS?= =?us-ascii?Q?ADZ6uYhvokQ8tOhYOSg4H2MMUJfEEAdm6c0GeTtOMLA6IXLNBxsmW7TZbEG1?= =?us-ascii?Q?FwHEM6QBs6Q6I9fKvJmhHU0s4ejMEZvRa4U6nyMxplpQSbfeGUCs+6tbC8mY?= =?us-ascii?Q?vcc5SA93YXUCHO6UkwshKK/YVQXGUI20QWHLZV/5pjRErhttLw1zuspul0sN?= =?us-ascii?Q?FSA7RIFOvFI3F8FzsEn7j+fU5QAeDgAukU+P30uX8S+92fAeDUu3V741EX8p?= =?us-ascii?Q?Wfm57EXDfMYVnTETDuvuBwoA/v+JjcEz8CfjZYjBuwXfoZHVEqvtgqP56tJC?= =?us-ascii?Q?59jPOf7eXnMOAqISJqc3x4KUy9GaTHJHMrxyIFsXQv0nd6o2rULouUeqCID0?= =?us-ascii?Q?9VoM2PKv5EX/cNZ8mizUj4GuyXPM1Z+FlsfXjJwdKJP2mU8S5Gy9Sy5mxZ6d?= =?us-ascii?Q?HFU2+EPnNVBcA5vNLf8SHd0KVpDcDsD0Fl84BFN6Knofs/KnkAoK22mScKeB?= =?us-ascii?Q?9Z2Ytk3q9A7yYSzc9HN2Wq2oULKVAgn/CETHve+QEY0XtPYp0+aGwlvJxJ7D?= =?us-ascii?Q?7gc8Nbt34R9oWLlE81bnBTmSMVV+PslFs4CAVx/1r4cJBQgVbwd6bkFJrXHD?= =?us-ascii?Q?2e3njhvyf/NbJBqXGtNi+csS55w0D5Ltk/lAYRNNhwhsNggV/2WuSXD2Zr6Q?= =?us-ascii?Q?cbszXgWCFQfB8m03LzF6792BhM6hWUEierBvCJ54BYmMbH9fsd+jU83d6XkD?= =?us-ascii?Q?SwEUkryn7JN57kJnnhbQwlhhMwoNoN/pepoCgnfwsSwD+T8hDgKgjURjoDLb?= =?us-ascii?Q?gtftS/a0TQXHRTuXFbcfnqcrpZRyvQRmlCpUpOjk8IPCscM/B9tI14G5+dCG?= =?us-ascii?Q?5NuGov/HHLq5pmw4i19HQURaQSJ3VcV8tYVS8O6XZq8EtLHrYD7lbOcZ3ooS?= =?us-ascii?Q?a3bn5+2MB/1HagWiRK2cqPa2+dxfJaS/EWCs75fRjwEeruueuadbEBjrvIq4?= =?us-ascii?Q?3Hwm+fwjU4b6RB8tuIWpeV5Vg5hFZPbb63qNcHEJ0FGob7wntUtqxJQ9SY4k?= =?us-ascii?Q?SMN/XKDg39AdlxRoGvqSJgjRy5NnV3KbcyymkI5xp9Hdu8VkfTH8qrOLoV8Z?= =?us-ascii?Q?37dt81Z7fxEMBqGKOwZl1MyyaGAEKIBWirNNGXPjGK4B2e5HYXvyTHdYdBC9?= =?us-ascii?Q?qbxUtWicgLbQv0cplcEwfD+Z6drK8upee+QSEXTs2rdcoRHiroHjGCEC/uaG?= =?us-ascii?Q?LBPu2CwcSjx1gPA85bKGkxAHSRRkPVyF0C7vsZSMG3LvvPhbOLtAIKspYf3a?= =?us-ascii?Q?6gExuaZEesugWQ7o4hhqz2RVbMTJ3DEEjePbV4iveX7jPIrByqY3rIxXiup1?= =?us-ascii?Q?zydYQ3b8VTCvmq3C/x5vvvF3vReJ5uFsJaWSIAtVZhlu7a2n73xZUgHva+jw?= =?us-ascii?Q?mwmk0IJSSRTKnZAts1woqIlTWuXUVTWo22spoR3mGyJoY7kRK9afL1GnbyyS?= =?us-ascii?Q?ljzd0W47uKPmmbRg+SSRavFNqqljCxoLeiUmdkYH8IDCZhhdWA7gRZcYxOZV?= =?us-ascii?Q?gxI7ZV+Mq8ONv/Ade2dG8sCR7KxYivHcnpxSL8xa4C9FdkEcQmxyPxMl5bxE?= =?us-ascii?Q?jU9T6TUgzU4ukBBVk+uifdGmcLbXT+4=3D?= 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: 4c5f2e77-6c4d-4747-a1cd-08de4eda066c X-MS-Exchange-CrossTenant-AuthSource: DM4PR10MB8218.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jan 2026 17:19:05.3078 (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: Wt2kNqCLOP3S/AJTmy5v84hdQOLYseCJ/ZufwUwA/Tg3b+qwlzPbFcQgUAXqa2giTdnEtZUHucnyTyrbaOvU6l9dAhfFbB6cYRYlYKBaGB4= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR10MB6524 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2026-01-08_03,2026-01-08_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 bulkscore=0 suspectscore=0 malwarescore=0 adultscore=0 mlxscore=0 phishscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2512120000 definitions=main-2601080128 X-Authority-Analysis: v=2.4 cv=B5i0EetM c=1 sm=1 tr=0 ts=695fe711 b=1 cx=c_pps a=zPCbziy225d3KhSqZt3L1A==:117 a=zPCbziy225d3KhSqZt3L1A==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=vUbySO9Y5rIA:10 a=GoEa3M9JfhUA:10 a=VkNPw1HP01LnGYTKEx00:22 a=VwQbUJbxAAAA:8 a=20KFwNOVAAAA:8 a=p0WdMEafAAAA:8 a=feYJxv-PvuhrjdhfU70A:9 a=CjuIK1q_8ugA:10 cc=ntf awl=host:12109 X-Proofpoint-ORIG-GUID: hwO2s7sH7JB_zEVuz_V-6vZZWuD1v7KT X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMTA4MDEyNyBTYWx0ZWRfXyL4mMRlMuc1G jy+aC0EwfQA84xLat/KFmrQ4Xktl5iBG4pOGw3e6O5cpLlrqMJB7Z2oTKFg12IMlTPogmkhBxF3 Ik7D7lXJf6+TG1PlzUW6MbcMiO+T5uF198lKlqgP3J1t0YqGHHkguPuxkUuw0DT7ijOaL9n8RUa lW2rJMEfctXgB1YgqbUfJESWr6wBZGn4f5uPzHmNtskFaG9p9XwAxV/Wmt9UOHDjJqH0+eZSYyf 3ue8/yp1RCPmXI8frvDhkN+NWiSLvaJs4MPxcWmyT4pj7pY/Uxl21Ix1kY1t9sqZ0DwfvJT1EyN mqqJ0jp4qjYtBSenP5iAddAv/ci1mMwgjesCEw6xrGtZx8yuay2Xwvvd3ZmZOZmMnZasgwZ4M8u tFEZb+KL4m9F1isQDlnTO4bmUll+4x+TyP3YXZDbH18fQUiAclC16wWtCo002ikgDKmHam3Pc+j vy/+sazlr2uPuGEAWvOdC+1QGaEtfxYZMZaYwY2I= X-Proofpoint-GUID: hwO2s7sH7JB_zEVuz_V-6vZZWuD1v7KT (Sorry for multiple mails replying to same, lei/lore are broken again so my setup isn't working properly). I tried to fixup the conflicts here to run tests locally but there's too many and I messed it up. Could you please resend this series rebased on mm-unstable please? Thanks, Lorenzo On Mon, Dec 01, 2025 at 10:46:11AM -0700, Nico Pache wrote: > The following series provides khugepaged with the capability to collapse > anonymous memory regions to mTHPs. > > To achieve this we generalize the khugepaged functions to no longer depend > on PMD_ORDER. Then during the PMD scan, we use a bitmap to track individual > pages that are occupied (!none/zero). After the PMD scan is done, we use > the bitmap to find the optimal mTHP sizes for the PMD range. The > restriction on max_ptes_none is removed during the scan, to make sure we > account for the whole PMD range in the bitmap. When no mTHP size is > enabled, the legacy behavior of khugepaged is maintained. > > We currently only support max_ptes_none values of 0 or HPAGE_PMD_NR - 1 > (ie 511). If any other value is specified, the kernel will emit a warning > and no mTHP collapse will be attempted. If a mTHP collapse is attempted, > but contains swapped out, or shared pages, we don't perform the collapse. > It is now also possible to collapse to mTHPs without requiring the PMD THP > size to be enabled. These limitiations are to prevent collapse "creep" > behavior. This prevents constantly promoting mTHPs to the next available > size, which would occur because a collapse introduces more non-zero pages > that would satisfy the promotion condition on subsequent scans. > > Patch 1: Refactor/rename hpage_collapse > Patch 2: Refactoring to combine madvise_collapse and khugepaged > Patch 3-8: Generalize khugepaged functions for arbitrary orders and > introduce some helper functions > Patch 9: skip collapsing mTHP to smaller orders > Patch 10-11: Add per-order mTHP statistics and tracepoints > Patch 12: Introduce collapse_allowable_orders > Patch 13-15: Introduce bitmap and mTHP collapse support, fully enabled > Patch 16: Documentation > > --------- > Testing > --------- > - Built for x86_64, aarch64, ppc64le, and s390x > - selftests mm > - I created a test script that I used to push khugepaged to its limits > while monitoring a number of stats and tracepoints. The code is > available here[1] (Run in legacy mode for these changes and set mthp > sizes to inherit) > The summary from my testings was that there was no significant > regression noticed through this test. In some cases my changes had > better collapse latencies, and was able to scan more pages in the same > amount of time/work, but for the most part the results were consistent. > - redis testing. I tested these changes along with my defer changes > (see followup [2] post for more details). We've decided to get the mTHP > changes merged first before attempting the defer series. > - some basic testing on 64k page size. > - lots of general use. > > V13 Changes: > - Lots of minor nits, cleanups, comments, and renames > - Bitmap function simplification and more helpers (Wei, Lorenzo) > - Max_ptes_none (0 or 511) restriction > - commit description expansion > - list all reachable enum values in mthp_collapse() > - Fix ppc64 compile error due to using HPAGE_PMD_ORDER (replace with > ilog2(MAX_PTRS_PER_PTE)) > > V12: https://lore.kernel.org/lkml/20251022183717.70829-1-npache@redhat.com/ > V11: https://lore.kernel.org/lkml/20250912032810.197475-1-npache@redhat.com/ > V10: https://lore.kernel.org/lkml/20250819134205.622806-1-npache@redhat.com/ > V9 : https://lore.kernel.org/lkml/20250714003207.113275-1-npache@redhat.com/ > V8 : https://lore.kernel.org/lkml/20250702055742.102808-1-npache@redhat.com/ > V7 : https://lore.kernel.org/lkml/20250515032226.128900-1-npache@redhat.com/ > V6 : https://lore.kernel.org/lkml/20250515030312.125567-1-npache@redhat.com/ > V5 : https://lore.kernel.org/lkml/20250428181218.85925-1-npache@redhat.com/ > V4 : https://lore.kernel.org/lkml/20250417000238.74567-1-npache@redhat.com/ > V3 : https://lore.kernel.org/lkml/20250414220557.35388-1-npache@redhat.com/ > V2 : https://lore.kernel.org/lkml/20250211003028.213461-1-npache@redhat.com/ > V1 : https://lore.kernel.org/lkml/20250108233128.14484-1-npache@redhat.com/ > > A big thanks to everyone that has reviewed, tested, and participated in > the development process. Its been a great experience working with all of > you on this endeavour. > > [1] - https://gitlab.com/npache/khugepaged_mthp_test > [2] - https://lore.kernel.org/lkml/20250515033857.132535-1-npache@redhat.com/ > > Baolin Wang (1): > khugepaged: run khugepaged for all orders > > Dev Jain (1): > khugepaged: generalize alloc_charge_folio() > > Nico Pache (14): > khugepaged: rename hpage_collapse_* to collapse_* > introduce collapse_single_pmd to unify khugepaged and madvise_collapse > khugepaged: generalize hugepage_vma_revalidate for mTHP support > khugepaged: introduce is_mthp_order helper > khugepaged: generalize __collapse_huge_page_* for mTHP support > khugepaged: introduce collapse_max_ptes_none helper function > khugepaged: generalize collapse_huge_page for mTHP collapse > khugepaged: skip collapsing mTHP to smaller orders > khugepaged: add per-order mTHP collapse failure statistics > khugepaged: improve tracepoints for mTHP orders > khugepaged: introduce collapse_allowable_orders helper function > khugepaged: Introduce mTHP collapse support > khugepaged: avoid unnecessary mTHP collapse attempts > Documentation: mm: update the admin guide for mTHP collapse > > Documentation/admin-guide/mm/transhuge.rst | 80 ++- > include/linux/huge_mm.h | 5 + > include/trace/events/huge_memory.h | 34 +- > mm/huge_memory.c | 11 + > mm/khugepaged.c | 696 +++++++++++++++------ > mm/mremap.c | 2 +- > 6 files changed, 618 insertions(+), 210 deletions(-) > > -- > 2.51.1 >