From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) (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 8D07C5CDD1 for ; Wed, 14 Feb 2024 15:39:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=198.175.65.13 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707925200; cv=fail; b=gQQEISpakpl5gMVBKJMjHuILklG683kuBbloEBNOdwIZjvQfijZCek1tVZdLOD8mknZsk0bausCGZMdoDdSmI+P/oqOE+AcMDKM4LzProm2BfmbYi6PlsVHhBGr7R/4dKYp/z7oD1/eXpuG6oEluvVgLLA8PywXkqrzwFD628gQ= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707925200; c=relaxed/simple; bh=iE47x0a7qsyNNicLxHP/tljK78XHHDCxMu85eGLy3sU=; h=Message-ID:Date:Subject:To:CC:References:From:In-Reply-To: Content-Type:MIME-Version; b=GGHqc42GdjRieN/Q4GsdLKEWVScmFovZX7zN4OV52+75MrtP0Syb8Y55sL8eDEoIDW7VIrDvuWjsBedWhSdlkIFXbs3VAdJibRvMgqQyBwS2okfplCwXE4BH66gASvpED92C5VBIrw/FwQj3tvAOrTSLZxH8o3a48BT3V0dUxT8= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=MwZQxKsC; arc=fail smtp.client-ip=198.175.65.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="MwZQxKsC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1707925198; x=1739461198; h=message-id:date:subject:to:cc:references:from: in-reply-to:content-transfer-encoding:mime-version; bh=iE47x0a7qsyNNicLxHP/tljK78XHHDCxMu85eGLy3sU=; b=MwZQxKsC5U+BvO4mH9REcezRonOukjwzPnvP8eAKDvtbNyEHdDgaA5SX Nz/gfz0ijIEVzWnaDJHGt8+tVkdN5RK9fMWQjr7PXK8evomIflKv7QkMv m9/GjoA1rRdm4yFmys2fOIFJdQeK3TExW2dFL3VqrUZxtM7o/onMrkW60 F39n+wCZiR+z+IbpDvozrVe7kobaUr44vitmMmWkDni0AWPRtIs2hTje4 9RhQZQxVS/Nn04yU8FV6rBZXUBX5mkiim6gVCgpsjsnuFXeU4ICV/tVhN PJjCEXxTTQWEg+xrPETXNdjFZgxh2epI038lZUN3vfl50dMc4TD+PYLub w==; X-IronPort-AV: E=McAfee;i="6600,9927,10984"; a="13069854" X-IronPort-AV: E=Sophos;i="6.06,159,1705392000"; d="scan'208";a="13069854" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Feb 2024 07:39:58 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,159,1705392000"; d="scan'208";a="34040337" Received: from fmsmsx601.amr.corp.intel.com ([10.18.126.81]) by orviesa002.jf.intel.com with ESMTP/TLS/AES256-GCM-SHA384; 14 Feb 2024 07:39:57 -0800 Received: from fmsmsx610.amr.corp.intel.com (10.18.126.90) by fmsmsx601.amr.corp.intel.com (10.18.126.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Wed, 14 Feb 2024 07:39:56 -0800 Received: from FMSEDG603.ED.cps.intel.com (10.1.192.133) by fmsmsx610.amr.corp.intel.com (10.18.126.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35 via Frontend Transport; Wed, 14 Feb 2024 07:39:56 -0800 Received: from NAM12-BN8-obe.outbound.protection.outlook.com (104.47.55.168) by edgegateway.intel.com (192.55.55.68) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Wed, 14 Feb 2024 07:39:56 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=EeppTokEwSVJE9Rms0dDQtx+ARt+P9Zey4KNS9/OL+jr0ElFYYFczw3LmZBtd9qJIwrD1SupTuSVqkRum8+Toy/h6V0zB9dII0Zy4fd5RpntHYKXlImhfg/SQtYJItOpm5wFbr5EjlBCbovePfN5dUM9Gf3Tw4FewiT03sJ7VefpRcYW5eWh6M4N62GnzdjhREIBLRnNQNQHIssu/Xkr61JFNxmo7wa7mlvD/DPzBrznLmJMlfGTi8N/IWZRRR1i7ueBwF0fHR4/J8TieprDphI2yTz6o2gY+VMElIB2Zgy84t+nPmUixwIOO68wq0o5MZmpeEWk0GdtxtjBcJHLmw== 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=4zu0c62UcR56VSGO0EiG6i+TAerb9iRwSlnUS1VYKoM=; b=hWGv68c/fXGVLri4rJAYju0k0Lzw7PmLDJRdVBcK6OZu0TzD9+d07Saw7REpl4RWkB6bg1Y3L6E/0XOMHFiF06UTOEn43jrKeTLhatZKT2onALe8l1DpkBawsLyHIYlBH7oncmQjBgkOPLUtBupQVh+Osayf3N0YUXjTI6/hhavcc24S1q9nV3IwFuudpe/Fia8DOr7Spq0K/tagjSoYe0ZqCeMrHV7Mds1fPuHKimoCoqJ1XVFS893qCDCL9BI6XaIwWSTtmvrtjqQc6r6L5pRK3j1daV0vt5iD1sn6FLPMWsl+HUexGWthhZKarEERcrV+AC3Oq4VWGY9G0Ch0pA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from MW3PR11MB4538.namprd11.prod.outlook.com (2603:10b6:303:57::12) by MW6PR11MB8367.namprd11.prod.outlook.com (2603:10b6:303:249::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7270.39; Wed, 14 Feb 2024 15:39:54 +0000 Received: from MW3PR11MB4538.namprd11.prod.outlook.com ([fe80::d019:7cb9:3045:5082]) by MW3PR11MB4538.namprd11.prod.outlook.com ([fe80::d019:7cb9:3045:5082%4]) with mapi id 15.20.7292.027; Wed, 14 Feb 2024 15:39:54 +0000 Message-ID: <8fa3c29d-c7d3-421d-b567-e9bf997e6751@intel.com> Date: Wed, 14 Feb 2024 07:39:53 -0800 User-Agent: Mozilla Thunderbird Subject: Re: [Intel-wired-lan] [PATCH 1/1 iwl-net] idpf: disable local BH when scheduling napi for marker packets To: Alexander Lobakin , Alan Brady CC: Jesse Brandeburg , Przemek Kitszel , , References: <20240208004243.1762223-1-alan.brady@intel.com> <2e3001f8-a079-4d44-863f-979baca3b38c@intel.com> Content-Language: en-US From: "Tantilov, Emil S" In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MW4PR04CA0233.namprd04.prod.outlook.com (2603:10b6:303:87::28) To MW3PR11MB4538.namprd11.prod.outlook.com (2603:10b6:303:57::12) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MW3PR11MB4538:EE_|MW6PR11MB8367:EE_ X-MS-Office365-Filtering-Correlation-Id: 7297933b-4575-403f-b1ff-08dc2d733103 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:MW3PR11MB4538.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(396003)(39860400002)(366004)(346002)(376002)(136003)(230922051799003)(64100799003)(451199024)(186009)(1800799012)(5660300002)(2616005)(316002)(110136005)(54906003)(41300700001)(2906002)(36756003)(26005)(38100700002)(86362001)(82960400001)(66946007)(66556008)(8676002)(66476007)(4326008)(478600001)(6636002)(8936002)(31696002)(53546011)(6512007)(6486002)(6506007)(31686004);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?N0JyUmNMV1diT2tzaVV6UHp2YlZLOTNlMDhma3graXpBamNxTmYwdzJxclVH?= =?utf-8?B?UnlxZXg4ZTFMdjZadXdnYkY3enQzSW0wRGNzdXdYQ2VCNmloU2dOWktoNFlk?= =?utf-8?B?TmRJMUpLOUphaERlOFVXeEd0b09mK2xmUXd4M0hpZmFQSStGTHJEYUg2djdW?= =?utf-8?B?ekYyc0NqbmhqY2FhRldvY0crRk54YW4xWnRVZ0Y5clZwL2Rvb01mcDR5OFUy?= =?utf-8?B?WkE3Y1F3RFBoY2dHV3Z1QmtlbCtnL3dWUjNlZzYyT3ZBYkFXbzdVT1FxUVNX?= =?utf-8?B?NHdHS01JNnBGWlFlZlArbGtYV0pDWjFVQTFMN1BIbVJHK2IxLzduUEtZa3JH?= =?utf-8?B?SnpwRlJJVFRNcnRRMGFscE9ZaXF3ckk5VThZSHdKd2ZuZ1ZFdlh5V0ZpVWlI?= =?utf-8?B?NmJnQ21pc3FVV3hMYU5ocVpEUUhkK21ZYWNOU2d0eXRoZjNacXdrdW5GYTRj?= =?utf-8?B?VE52MVZTaE9lN0x6MzZsN1RBdHhFUDNHRmNrUWY4UVQzenU4RzRReS9UK3kw?= =?utf-8?B?T2pnMTB3TnFNS3ppczRWTWJZVnJQV3Fyc3lLZzlXN0syeE9DeXdQeWhTM2lU?= =?utf-8?B?M3pWM2pqL1JrMm1oZGpyMjVDTk90R3hrSzg5VnhuRFhTWnZYUW1GN3NTSEZN?= =?utf-8?B?Y25kSHpzeGVIVGJuT08zQXJDMFcva1dkYk5BMDcrTldSYzZSalJYeGpJUVBG?= =?utf-8?B?TmxISm4razh3K0lVYzRnbWZOQzZMKzFlaGQ3aldUSFlvbGo1c25LdzUwdWZt?= =?utf-8?B?dzVTaG5STHY5L2pGTGN3Z1l0Vy9PMUlHbUYwalFoWDlqYXhiRCtBQkN6cjlV?= =?utf-8?B?NUdKZUtLTTdhdFFUZ3ozWkZMY0NSVFZjdGZ4M1pRWFRjRkJsOG1MamxSMjFt?= =?utf-8?B?U3U0dU5ralpzNjU3YXBNemxpWjJnMjJPOXhPVmFjR2g4cWpMUW53ZGtIdTNI?= =?utf-8?B?YjdocGllZnd6R0VQbWpiV1FiNTFUUGFlc3pJNGxjcmdpZVB5QSt4elQ1dm92?= =?utf-8?B?MnJBOXRHb05sOFBSQjAxTWMyTDFISk85TE12dHBYTEtndHZVKzIyaDVDYjQw?= =?utf-8?B?OUFuQk1DdkwwMXVyYlk4NHpUV1ZHYXYwdDgxK2tpVnUwSkRUOHNtREZQWHdQ?= =?utf-8?B?L3hpRUJBbm1vOFR1V1o3WHZpcWd5MFhicGZhdWRydkpVbkplaEdsOVowMEhB?= =?utf-8?B?bVdpVmR3OHhoVGJjSy9Vd3RUSDk0WkJXb0QvUnZZK0pNWERWemU2RmprK1VR?= =?utf-8?B?bk5IUGNWR1dhSjFhRElUSDZnb0pjRFpoM0F4U0JuYkFYdW1CMmxGTC9YQTZq?= =?utf-8?B?dFFwenovTFZpVHB6T2FhaUNsVDJrSFRQRzNnKzZMc1d4UndiOHUrQkJxeEFk?= =?utf-8?B?b21hUWE3aXNRUDljZG9UUW1MWkREd3Vxajd0TlNzRWNITm1HOC9HYnhmTXY5?= =?utf-8?B?cFMrUEJQb2Rkb1p5UEw2SW5PS1pKL2k4VTI0d052TFI4SS82cEc4T2poS2F1?= =?utf-8?B?M2lHemgwQ09hbWh0WEF5ZEFZVjZibi81eU92ZWs4dFcrajJNU0lZbEJNVzhL?= =?utf-8?B?M1V2T1RMS3Q3ZGJzZmt6ZFY0QmxXdXJTMDZmZERvZEt2SG5icE9maDFhK1Vr?= =?utf-8?B?a0dvNU8yOEtKMDJVVExZOFVTNDdBOUpGVGUwNVYwQW9qd1F3bDBVWktFcFBD?= =?utf-8?B?eW1FcWhWRi94R1c4YW02ZURhZnV5d0xJV2ptQzJjL2FmMEoxQ1FwUmhRSER0?= =?utf-8?B?cWUxbTUvK05sWllpaEp4OVBJUFdIbnRmdjVFZXZpKzZSUmV4VExFaDlzVERl?= =?utf-8?B?dmJZako4RS9DZ1hENGlVZGJvWTBUanFIZWxwbnlUdVF1TDNyR1BlZy9mejRu?= =?utf-8?B?ZCtmaWVKeGNJcTBiajZjdEJ1VU9RVHJOaHY3MUVBakhHc0VMNnJEd2R0bVFt?= =?utf-8?B?bnRqSjI1SmlJcWs3MWc4NWRoTFdvYmdBWEpFenAxQm1nVDZHNDBpNVdYTDFz?= =?utf-8?B?aEdOS3RPTE82TEQzSlZUbnJzQTh3UnhzTWxObVlCT2d0dGhmSUxqL3VrSm5o?= =?utf-8?B?blNLKzhYdVRWZlZPcmRTbVJZaU9ZOGUzbDBtQWlPM2cwcVVjQlNUQU0vcmdq?= =?utf-8?B?TCs0K29lRUdOaXJ0VGVCL2tGRnZqNDF2Y2x6bUFLZ3NtbnlSSkwvRytlSE9J?= =?utf-8?B?UXc9PQ==?= X-MS-Exchange-CrossTenant-Network-Message-Id: 7297933b-4575-403f-b1ff-08dc2d733103 X-MS-Exchange-CrossTenant-AuthSource: MW3PR11MB4538.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Feb 2024 15:39:54.7452 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: nou5n2aDAJ+6qZpfus1POIaG9XAq/fsREjq9MDynGFT5XhQ+UMHKCoLDNx0NNUUC2S69vvu4cKPOWHqpfcIOpN/L7doPISrOkE+4YZh2k3M= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW6PR11MB8367 X-OriginatorOrg: intel.com On 2/14/2024 6:54 AM, Alexander Lobakin wrote: > From: Alexander Lobakin > Date: Tue, 13 Feb 2024 14:16:47 +0100 > >> From: Alan Brady >> Date: Wed, 7 Feb 2024 16:42:43 -0800 >> >>> From: Emil Tantilov >>> >>> Fix softirq's not being handled during napi_schedule() call when >>> receiving marker packets for queue disable by disabling local bottom >>> half. >> >> BTW, how exactly does this help? >> >> __napi_schedule() already disables interrupts (local_irq_save()). >> napi_schedule_prep() only has READ_ONCE() and other atomic read/write >> helpers. >> >> It's always been safe to call napi_schedule() with enabled BH, so I >> don't really understand how this works. It's been a while since I debugged this, I'll have to take a look again, but its not so much about being safe as it is about making sure the marker packets are received in those cases - like ifdown in the trace. > This also needs to be dropped from the fixes queue until investigated. > For now, it looks like a cheap hack (without the explanation how exactly > it does help), not a proper fix. It does fix the issue at hand. Looking at the kernel code I see multiple examples of napi_schedule() being wrapped with local_bh_disable/enable, so this appears to be a common (not uncommon?) technique. Thanks, Emil > > Thanks, > Olek