From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (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 6343119D8A3 for ; Wed, 8 Jan 2025 22:28:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.177.32 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736375311; cv=fail; b=QIStebELtkBjsEsIZJHP0lNMPlA0YOSsPHj1GSv9Nz0DZ9m49dPwBVwXpKEaCkvnZk/hmNby+jBiFBW4fEkQqVN4IdPh9qlUotZOEMaO+5lmNJzDIXrPuOiRtMQzr+ccyRt7dQPJKBH9aN+onlJIn/MJ4jMNBuVrUpUEVzmpIko= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736375311; c=relaxed/simple; bh=nj3+yc7fwfst1ycyC0X+mRRF+9i5kKfZmUZ8WyFl4do=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=DEucvpT6dXBpwxPtufktetg1z72o9tTfv5lVT7Vn434aSTuQ40QVMtlPAxXyIQFbgBS5X6UOpfPxsh4FXXvsyDBcD2iNhv9wceSRdwxIlbadKRHaM76zxd2XNLBnWttd42OarQXq5T5yX+BCUkg9Z9LRfLOMzMlCeJLcYvbfLpE= 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=LaU5+Q/j; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=A84cC+5C; arc=fail smtp.client-ip=205.220.177.32 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="LaU5+Q/j"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="A84cC+5C" Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 508MAKiI030518; Wed, 8 Jan 2025 22:28:18 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-2023-11-20; bh=dXAGSzXJJ4l21ZyvM2ZLs74OO7aK+16f+nkkxgVgqd4=; b= LaU5+Q/j61sJLaM8AHQ9+8KqtXIi+ukRnqSa4BJPjHJcHJodjoWdN4PovSQ2zeMh gRjDznaNrvc2GGQ7hMgLyZTlwQ3q7qAPsM6xZsuZwyBMZx7o39gbm7o0b3tzZPci nPPdRHisFnQDwpP/YZEyVjQt5NqP7KsLeXkwMxJODV5KMsTkYo1V39T3w2b/f99z GGoSroP92L/3kitkwTKVYUUCE26ckUIfhL4UlgtUl7le8hvAsatsTA9NOeVmP0mE mBVJycJX8uuOMgJg2YMLCTiOHTvnSAXV682qNQCCVTVpBAWIbb5K03lDjTv72z4n V85DtjmEGDN7u0xvFE8rRQ== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 43xudc822g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 08 Jan 2025 22:28:18 +0000 (GMT) Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 508MF9Im026551; Wed, 8 Jan 2025 22:28:17 GMT Received: from nam10-mw2-obe.outbound.protection.outlook.com (mail-mw2nam10lp2041.outbound.protection.outlook.com [104.47.55.41]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 43xueakkam-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 08 Jan 2025 22:28:16 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=FM5DxOv4WOLQhub2QpEtw4kL1TU4ADyL0HDZ4T0CLNZQLSZk7/BJRR7UAg4+axuanAWcmsBH3pbk4lb2N6RapkAO9vDK04SU9W6SvR8JfZ2ZCKPTkmv/fq4GSZjun53+wS/+lFPxDvb9NsiOByzbZ1IXzWzQUG8qtmsQXqJcDJIawlUHFkJjVuoXsF1apejd90epoCp74dq+2zwFZDULCDB1FxE0af+f7VQg/4GNShsSQf1+j5UjRXi3JgMhwSkejfe+vLDabfKv9/ORhvRijGpzpwFyh/x/CalbvkUEO0oprcDBRrbUIZVg8BtNNQBl9lrZuQ7zPAWwVs+PwclV3Q== 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=dXAGSzXJJ4l21ZyvM2ZLs74OO7aK+16f+nkkxgVgqd4=; b=htk7QXu96wX6/i+4yNlHG6sDu9mREvdIuEap7wWMFjwzXE3YnaH5Xe2R7hYSY+dpsWT6gH+tRCguStEA/+jvciZd2yet/ONtjG54zmHEeSpXxNZK+92x9WF0di1DGvKLwwmrypneqrn4ZHhb6QDcx1xP5F0s1sCkrAYtvtMqb0IHEs5T3DrOgpJr3BMLdQ0Vad8cQQUPSxUxb8YJlKdlMP+aWZ2neO4DXIBO6hwiXHomYiNjEkCQil7KwSgoiZAIHKPR08ROPScV+mHmXSN/EFWtD/1uh0q3RqQ2fYCQcndEGPIvJYyst2hq2YgOh/KNdn3Ib2/8nBiJrOPzq7V3CQ== 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=dXAGSzXJJ4l21ZyvM2ZLs74OO7aK+16f+nkkxgVgqd4=; b=A84cC+5CIFpNPxZxoV2t6bCDb8eGz0mMxNFLt6LMYY+vzjIrD/gREILvADO4xH1bS1dwm58hGyR8fxo17lraJI7N3T4FRJbJnawx8ZG3xev2wS/i3iutAwUswJpqV5VA2BOp5zjklndjn2qnOnN+/O6xzrdPrXFBIfVwUjCiPwE= Received: from DS7PR10MB5134.namprd10.prod.outlook.com (2603:10b6:5:3a1::23) by SJ0PR10MB4592.namprd10.prod.outlook.com (2603:10b6:a03:2d8::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8335.11; Wed, 8 Jan 2025 22:28:01 +0000 Received: from DS7PR10MB5134.namprd10.prod.outlook.com ([fe80::39b2:9b47:123b:fc63]) by DS7PR10MB5134.namprd10.prod.outlook.com ([fe80::39b2:9b47:123b:fc63%4]) with mapi id 15.20.8335.011; Wed, 8 Jan 2025 22:28:01 +0000 Message-ID: <51c156f5-e70c-4a75-873b-68fed4fad998@oracle.com> Date: Wed, 8 Jan 2025 17:27:59 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] nfsd: add scheduling point in nfsd_file_gc() To: NeilBrown Cc: Jeff Layton , linux-nfs@vger.kernel.org, Olga Kornievskaia , Dai Ngo , Tom Talpey References: <> <173636890368.22054.15435316321445899208@noble.neil.brown.name> Content-Language: en-US From: Chuck Lever In-Reply-To: <173636890368.22054.15435316321445899208@noble.neil.brown.name> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: CH5P220CA0014.NAMP220.PROD.OUTLOOK.COM (2603:10b6:610:1ef::15) To DS7PR10MB5134.namprd10.prod.outlook.com (2603:10b6:5:3a1::23) Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR10MB5134:EE_|SJ0PR10MB4592:EE_ X-MS-Office365-Filtering-Correlation-Id: 2aa5b5f6-64b9-4616-6647-08dd3033b5d8 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?UklnV1l2RzltOThTazhCM1FRRmFQSEVqdExPblFmcDQ2M1M1RExtUGQzMkZm?= =?utf-8?B?MXBsUTdwR3lRZHV6RlNqYTFUeFczaUFVMFhvOFBHOUszdlZWOWhhZmRRSGNM?= =?utf-8?B?SHJKWDIwQnpFVjlWV2J6NDZEK01RaDExdjdoK3RybjgzcGIrckVRZjNneGp3?= =?utf-8?B?ZGViY3hCVGJkQTdEbktCS25pOWlrMS9nZnNTc01EckFsTU1LMy9icjZIMG4y?= =?utf-8?B?VndUTFRjemhURjNhSVhSSGh3V2NUTjVJcVJrNkEwZ2pSTXB1Y3Raenl0TWdL?= =?utf-8?B?VytnY3pZUUN3bE1hVzg4NXNURkZCcHRhK3FlNzNkUGZIRGlNY2J2WDd3bmJL?= =?utf-8?B?aTJnOURiVVdCOGZRSi93bVBGeVo0eFBrZ0crbHFhbzBHdCtKc2lUd2dPRDZ4?= =?utf-8?B?TjUwaENwY3pQVVM1QXhTRUtzc3JkSWdZOXZLS3BjZjVtY0JYY3FESmVsdTQv?= =?utf-8?B?dE5IWlN1OWlSRmFRRmRaM214VHhoUlpOWnozcmhiMkhIa0ZlSGxEUXM4SHFW?= =?utf-8?B?OXhzTmVKYnI5ZUpDNDdaNnhheGs2cTFBaWI3QVAzaTJ0Y3g2eW8wbnpvWk5T?= =?utf-8?B?TXlua25ldTVrUEJacW9DSmNMY2FiRHlmUFF6blNnVTFrbHhMWm5TbElmR2R4?= =?utf-8?B?UExVTGdJeHVoWVhQTXNBakx4L2NkUUozMGpkR2FOYU9rZGJ3VzdkUzcySFlJ?= =?utf-8?B?NExFZDNrVkxoaGFEbHFBa0FJUXhZTnFqYThEejhvN1h2cVFId2hMcU9xQlVq?= =?utf-8?B?ZVZMcVFINDFOZm5FTWdWRStJRlFpbnVyZS9jcWVXS1pqMi9aRjhJQk1WeW9J?= =?utf-8?B?bmQ1OGY0NkF4VWNwZDRaL0ZxUHZMVU1EREwzNlh2ZThJb1RmS1Vzb3FxZDNv?= =?utf-8?B?NWtqMEkvWXdjSXlJMUdzK3dhc29SWTkrQnNJVzNrT2RzSFRxRW9Pb3VlenlT?= =?utf-8?B?TUwwemtxUjU2dlVIRENwNlhZcmNZc2dmSG5jelpqY2pJbCtscnhhWlZQNlRJ?= =?utf-8?B?M1BCbTl3QWZETVBxYm90V1BvTFlIVWFYbTJUek5yNDZuU3R3dVNzYTBwdkFr?= =?utf-8?B?M0ZNdVN1Z0I5NklEZGpwK0V3ZWNUL1ZETTd4d3ZjOGtvdG4xWS8vMllEU1pn?= =?utf-8?B?NGtaTk00dmtvd0FKaUprakZvS05LYjFNL2hKYzZuZXR0am93OTJ4QnhDVzZG?= =?utf-8?B?ZHovM2hPU2htQ2VDU2hleTJKb3ZZUzZQWEVONENCeElTNnI1RmNMczV2YmZq?= =?utf-8?B?ZEZtclZWendFLzByZ0E0T1BjVTgwTmR5UUNmMGliMHRBeGlReWN2NkNMbE43?= =?utf-8?B?cFYxNnZGVmhFM2NHUUtYaDgzVnBwUFBnNUVHSnBub2podFRUaEVxcTZlV1hP?= =?utf-8?B?My9veUdkeUM5clZVT2J3Nk9idnpCcml5Mlp5Q0U4TXl1SUNLb05ZSnRhVVF1?= =?utf-8?B?TG9Rc1hzbXRwa0lkYVdFamxWTEdKSTZveThJclltSWhwSUtpVlQvdWFCaXp0?= =?utf-8?B?aFZRMEJLb1krRlNra0krbWp6QWxOMEJFMC9mWHYxaDVaUFd5cDdsMCt6Y3R6?= =?utf-8?B?aDFUNkVzY1ZveVVNZnovRjNib1IwelBnUEFrYXE0d3YzRnRRMzg2Q2RKeW94?= =?utf-8?B?akRGK2hPRjM5WUtpOWVwVWpoZndqdkM1cDczL2MrRktkdlFSYTFhQnJndlBy?= =?utf-8?B?VWRNcjYyMlBxek9uN2t2SmNWWDFhWEVlUStVdFc2cnBPaGtodlloS0xNTXkv?= =?utf-8?B?UkZMN0pnaHBtU0laY0UrVDZES3lrV1VGT3JQaGNRNGNzRG13QzAyV2xOcC8x?= =?utf-8?B?WjlJT3ZWZW1QS29RVGFQT3p5UzZ1QmdMRG9aRHFTUFZHNXV3c0NUWE5UNStF?= =?utf-8?Q?jPoJLXqyBwd5H?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR10MB5134.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?TUU0QUx1dGt5U1pYdHU0OEp1akJJRVdkUjh2eFVVR2FwQXc4OFkwZzV6VS96?= =?utf-8?B?VjJwQkNlN2UzTkNTc2w3VjBkZlBDbXF6VFo1ZkNrNHYvYjUzM25DT1luaHU5?= =?utf-8?B?SkpTSkZWKzI0R1o4bWV5ekZySTQxOTF1aU81VGdJWW5sYU9CeWRQY0NKaENq?= =?utf-8?B?UGJHbndHcUFwUnVGV3Fqb0FDcFUxREVlZkZrZlI5aGptSFBRM3psU3ZhN2Vt?= =?utf-8?B?ZGtxNW1JODRrekIwMTN1WWFSL0pybGdhek1JbjRLemJuN3lFbFRlTjdrT05U?= =?utf-8?B?NjVlc2lCRVZSQTEwR1VjNmN2Rk9lSUk0SGdISnByMjEvOHl1VDhzT1ZUTUZH?= =?utf-8?B?TkdVRHhqOVdmdGJ5M0pyT2htYTJOa3ZWUERZblhGUy9zcUhEblBvaHdMYmJK?= =?utf-8?B?TVk4S24xWkFIaFpvcVM2Mkd2aXgzZ3VzdjQ4TldQOWZPek9rTjVsd3NlV0c2?= =?utf-8?B?cFc5WGZRQmtuMDA0QTZzUHBOVHp1RXJncDNSVm1aSkVlMlpDblJ0ZTJSdURG?= =?utf-8?B?ckIvMVpNMHd2bXR3Mi9pamh6ZE9zRU4rbE1lT0lIdnpWdS9CQVVoK0RzV0dh?= =?utf-8?B?UjdNKzFpdTl5Vkd6OXAyS0txa3dwbWo1U1dFYzF4REpaUmlpZDBZS2cvZGpz?= =?utf-8?B?cDlFdW9wcjVYMkxINklUOWRSREZxM2ZNSURIdmR5UlFHZ1g1d1ZZenhHM2h5?= =?utf-8?B?K2hUZDd4dklmRDFiYzlmVm8rMlpIWG5DdS9XWFFqWUxUdG9wdUpTL2JkdTgv?= =?utf-8?B?UU1oL2h3R0FrNnV6c1lrVENQM2VkYzVUaldaNGZRRlFJT0ZBeHpXRnJrWmEx?= =?utf-8?B?NUtkT1JXS2NTNDRUcXZmV20vZktrZUk1dE5Qb3lxM0RxaWYwTmJ1d2U2Yytn?= =?utf-8?B?blBYcU40U1I5UmNOQzZsSWkvbkRNcEU3cWpHY1hQWDRRWGcxMmpsQjZTUmxE?= =?utf-8?B?RU9EOEdoUzlNSC9KZXg1c0dyaXlUQXpFN1NrV1ZHZElwYjlMN1JRSDArQkJO?= =?utf-8?B?eE1iRVB3bEFxWXV4LzdnbWxtd21MSFY4cFhYV3ZkaTJ3cTMvdkk1aHdQdzVT?= =?utf-8?B?UTVBaDA2RXZ2NDBxQWRQYm9taFhtVzM5NHJEczlRaDZuRTA4RVJhaW1nWER5?= =?utf-8?B?TzFQOFdCMkN4MEZFeXFSbFRvYU02WFErQjFEWm5ZcEJtQWVhNittZmlLUDBw?= =?utf-8?B?MVBUR0hMRTZvRXlzaFpITXY5ek1aS3BPeWk3VFAxNkFEamJpNkhTL0lEaGR6?= =?utf-8?B?QUxVb1lEbXN5OWVlSmNOMWdUMHBKUzV1eldONUtGVXV2Sk83eDdCanFRY2RJ?= =?utf-8?B?VnlPQ2g5VWVRTFZDVitmOEw5Y1Q2Q053T3ZmYk42Z3JXSEhSckhRUi9VNk13?= =?utf-8?B?UHRZbGo5aVNoR3BGMXBqeTFObGVPNzlKK3dhQUJ3NUxVQmJjcTk5ajFQdGZW?= =?utf-8?B?cWFybDFVNUZDWVNsL1dNTHJJdDNZQlRBUVdLWHd2YjM2MDE3SXhaejZVdkFw?= =?utf-8?B?U2NmcDYxVCthUE1qMStlRzFBV3QrRlhzQWlva1VaM3BRSXprclhYb092czlp?= =?utf-8?B?dWpQWnpmcWdnaHBocGhKb056cTd2cm5YOHdGaHFlMGoxZk5oOHdVRm5iM2Jq?= =?utf-8?B?QWdsWE5qRUhHWEdwTDRtR0xQckRrR0E4RlJ3T1Vad25GdHIzZUtmcy9EeWEw?= =?utf-8?B?eE5hbHEzVW9WMUtpQzdmYkRYNTRjQmVmdDdXSkFDSHc4QXV1bFVaT2M5MjJH?= =?utf-8?B?S3dvVlhYZDVrS3ZIYXlwcDZxTGllbmZFdklOYlpOdHZvNmxUYTFkQ1Voc0M4?= =?utf-8?B?VUoyUGFEN3hsRDFEZnVRR2p2TjN1RHNwQU45UklvUkdLUit2T2svTXQyL1Z2?= =?utf-8?B?ejJnN0dlM3ZQanpUZzFmbnY3MVp0L1FkcGozbWJwVkhRZ3Q5NVk5UERSbjQ0?= =?utf-8?B?bnYvM2l0UWdxRHZGVEUvMHI2QmdWUkoxaUFaRXlsNml5V1pCeWhrN1AraXR5?= =?utf-8?B?YmZCb2pkNmJlbG5aU2hRenhQNWxOeURLd2FIcng4SUttWkV0Zzc0UnZLUHdL?= =?utf-8?B?c2JQWWVTYWFlVnBmaklXZGRrbHBpMUhzVG1VN25uMXVmMUVMWkJVNHRYNHNH?= =?utf-8?Q?duml4xVUyhqXF1RNv+y2FiXLS?= 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: 2aa5b5f6-64b9-4616-6647-08dd3033b5d8 X-MS-Exchange-CrossTenant-AuthSource: DS7PR10MB5134.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jan 2025 22:28:01.3831 (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: 1FUc+O4ZmybvtdMLbELk3HLLTibtJXOQc108Iw9hmIEhr1xWb+oE44EqQeyhUckmVAj/3H971GPJbdFrulEU2Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR10MB4592 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-01-08_05,2025-01-08_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 spamscore=0 adultscore=0 malwarescore=0 phishscore=0 bulkscore=0 mlxlogscore=999 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2411120000 definitions=main-2501080184 X-Proofpoint-ORIG-GUID: BwYd-a6VbL3ilSez4McSsjb3VBOe8rhP X-Proofpoint-GUID: BwYd-a6VbL3ilSez4McSsjb3VBOe8rhP On 1/8/25 3:41 PM, NeilBrown wrote: > On Thu, 09 Jan 2025, Chuck Lever wrote: >> On 1/7/25 6:01 PM, NeilBrown wrote: >>> On Tue, 07 Jan 2025, Chuck Lever wrote: >>>> On 1/5/25 10:02 PM, NeilBrown wrote: >>>>> On Mon, 06 Jan 2025, Chuck Lever wrote: >>>>>> On 1/5/25 6:11 PM, NeilBrown wrote: >>>> >>>>>>> + unsigned long num_to_scan = min(cnt, 1024UL); >>>>>> >>>>>> I see long delays with fewer than 1024 items on the list. I might >>>>>> drop this number by one or two orders of magnitude. And make it a >>>>>> symbolic constant. >>>>> >>>>> In that case I seriously wonder if this is where the delays are coming >>>>> from. >>>>> >>>>> nfsd_file_dispose_list_delayed() does take and drop a spinlock >>>>> repeatedly (though it may not always be the same lock) and call >>>>> svc_wake_up() repeatedly - although the head of the queue might already >>>>> be woken. We could optimise that to detect runs with the same nn and >>>>> only take the lock once, and only wake_up once. >>>>> >>>>>> >>>>>> There's another naked integer (8) in nfsd_file_net_dispose() -- how does >>>>>> that relate to this new cap? Should that also be a symbolic constant? >>>>> >>>>> I don't think they relate. >>>>> The trade-off with "8" is: >>>>> a bigger number might block an nfsd thread for longer, >>>>> forcing serialising when the work can usefully be done in parallel. >>>>> a smaller number might needlessly wake lots of threads >>>>> to share out a tiny amount of work. >>>>> >>>>> The 1024 is simply about "don't hold a spinlock for too long". >>>> >>>> By that, I think you mean list_lru_walk() takes &l->lock for the >>>> duration of the scan? For a long scan, that would effectively block >>>> adding or removing LRU items for quite some time. >>>> >>>> So here's a typical excerpt from a common test: >>>> >>>> kworker/u80:7-206 [003] 266.985735: nfsd_file_unhash: ... >>>> >>>> kworker/u80:7-206 [003] 266.987723: nfsd_file_gc_removed: 1309 >>>> entries removed, 2972 remaining >>>> >>>> nfsd-1532 [015] 266.988626: nfsd_file_free: ... >>>> >>>> Here, the nfsd_file_unhash record marks the beginning of the LRU >>>> walk, and the nfsd_file_gc_removed record marks the end. The >>>> timestamps indicate the walk took two milliseconds. >>>> >>>> The nfsd_file_free record above marks the last disposal activity. >>>> That takes almost a millisecond, but as far as I can tell, it >>>> does not hold any locks for long. >>>> >>>> This seems to me like a strong argument for cutting the scan size >>>> down to no more than 32-64 items. Ideally spin locks are supposed >>>> to be held only for simple operations (eg, list_add); this seems a >>>> little outside that window (hence your remark that "a large >>>> nr_to_walk is always a bad idea" -- I now see what you meant). >>> >>> This is useful - thanks. >>> So the problem seems to be that holding the list_lru while canning the >>> whole list can block all incoming NFSv3 for a noticeable amount of time >>> - 2 msecs above. That makes perfect sense and as you say it suggests >>> that the lack of scheduling points isn't really the issue. >>> >>> This confirms for me that the list_lru approach is no a good fit for >>> this problem. I have written a patch which replaces it with a pair of >>> simple lists as I described in my cover letter. >> >> Before proceeding with replacement of the LRU, is there interest in >> addressing this issue in LTS kernels as well? If so, then IMO the >> better approach would be to take a variant of your narrower fix for >> v6.14, and then visit the deeper LRU changes for v6.15ff. > > That is probably reasonable. You could take the first patch, drop the > 1024 to 64 (or less if testing suggests that is still too high), and > maybe drop he cond_resched(). I will make it so. Enjoy the rest of your leave! -- Chuck Lever