From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM12-BN8-obe.outbound.protection.outlook.com (mail-bn8nam12on2054.outbound.protection.outlook.com [40.107.237.54]) (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 EA2DE261380; Mon, 24 Mar 2025 16:36:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.237.54 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742834194; cv=fail; b=ATgXg1XHAQyy+rxsdW4KhVlMK1LPnEwZ8UFWSxZ5ZkjNtvEc3ncX+qUTdjiFogA0TvGvclpnvBcmacH+LoLuYr1bAYGZW66BxnRYw5EMLx9GvrsU06Z1Gjdq+Iph9SDPIw4o29Nyyl/Z5F1XUYOwTCb6DKQv9/xXCuwYLYXOxLk= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742834194; c=relaxed/simple; bh=oCEn3jRNPNehwQB5WFa0UMuKZVbRPL18fOgQnuUI3ZM=; h=Message-ID:Date:MIME-Version:Subject:From:To:CC:References: In-Reply-To:Content-Type; b=qIEPvqugEwh7v9Vnx0N3uKb8TiVbreVK7nI2b5t42+lhRTwJoZToKAC8Tvm4rMqVnrrn2AHnvnDJ4rYSmgdNCTOCWdg35ZSg4G0PAVZPrMy75A/kB8ebEfoKDHyUN8TVfNbRPVH7I8e3qEPsTYAijZrAKZNfNHnc2x1nfRKK0w0= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=dl39hFLj; arc=fail smtp.client-ip=40.107.237.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="dl39hFLj" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=vUWTncqetaJmfsOc12f1bH/LZ582ZM4BMU0qGTFmIFL6NJS8+eqqoz2yI26qyL/P6xusKqa+fZZF4ft36Pxy12R62lDpT0q6WTuwwV6Xu+jyVZ5J3/3F9hMOvRK4xL9wOGjJtq8djZ4E+cJvEaNCHHXI64A/6kGDPe88TZE4xTVKhpixnslR6iMAQCgyZfooyXt6uYd8gXeheFT+xe5jLKPuCXmx0m3XuPEyAQVw5Msxucxzncw+F7+4jW7ovQ6rxlVVH+ItnJFpiur8hFtNNuUnCAvU0duDj0G43BDM6Z8gmSW/MNQd0xrC3x5Wl+PkJ8yKMmNjv4Caa/2LkOpZFQ== 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=zhGmZQTgiLPZ1W1OhAur0TXWOWkrOrPBVOe6h27CqnQ=; b=NoOK05F6xnBUGUZKNk6LSTQWp1ZcrykpIDSgpsqZJJUAmhNUBWWC1NXG9m6zW7z9KkBl63eDJJBQ/CwauT1rh2N5wtQVlgvDdIUf99/74yG97CYlRv38GiJ8onsWJIYyL9qBV/rfhxEtx3SyMnm2w9Cnwo+0Els984aOeuYI60SE7IIlWiSQbNXUYeVCy1vGI4MV1LSo2cEvUu2h+co2fnLHmsEwZgJfLFZ19+DfhbbM57zF7rcwfnn0xyz9X/BCLoIcPvyb5QT37KFQaPUw/Km5ZBCjtfTZGAyNmVSa1u/3W93gV90j4DkEasJqLK/4GVQp0YC+H2WVjPV3BhBqww== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=gmail.com smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=zhGmZQTgiLPZ1W1OhAur0TXWOWkrOrPBVOe6h27CqnQ=; b=dl39hFLjHiUorvgpRdDLOvYVNi/XFhT/siPxX0rw7j1HC7+GOj29RvqTn21wCAJsGv98cmffJhMek9/dvATPZM5V21727uKYHykogAnhoGKeCQpl8LCAoCKLMjziJ7BOOmBztID6uqiny1PIMUoRG5ICL1AsFNOD/5i6iBzuGaw= Received: from CY5PR19CA0084.namprd19.prod.outlook.com (2603:10b6:930:69::20) by SA0PR12MB7075.namprd12.prod.outlook.com (2603:10b6:806:2d5::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8534.42; Mon, 24 Mar 2025 16:36:28 +0000 Received: from CY4PEPF0000E9D8.namprd05.prod.outlook.com (2603:10b6:930:69:cafe::ba) by CY5PR19CA0084.outlook.office365.com (2603:10b6:930:69::20) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8534.42 via Frontend Transport; Mon, 24 Mar 2025 16:36:28 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by CY4PEPF0000E9D8.mail.protection.outlook.com (10.167.241.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8534.20 via Frontend Transport; Mon, 24 Mar 2025 16:36:27 +0000 Received: from [10.252.90.31] (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Mon, 24 Mar 2025 11:36:23 -0500 Message-ID: <569a9447-aec8-4afa-a709-caac6c6804fa@amd.com> Date: Mon, 24 Mar 2025 22:06:20 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [netfs?] INFO: task hung in netfs_unbuffered_write_iter From: K Prateek Nayak To: Mateusz Guzik CC: Oleg Nesterov , syzbot , , , , , , , , , , References: <20250323184848.GB14883@redhat.com> <67e05e30.050a0220.21942d.0003.GAE@google.com> <20250323194701.GC14883@redhat.com> <20250323210251.GD14883@redhat.com> <7e377feb-a78b-4055-88cc-2c20f924bf82@amd.com> <8fbd6f22-2086-4cf7-923f-ac95688c8ddf@amd.com> Content-Language: en-US In-Reply-To: <8fbd6f22-2086-4cf7-923f-ac95688c8ddf@amd.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY4PEPF0000E9D8:EE_|SA0PR12MB7075:EE_ X-MS-Office365-Filtering-Correlation-Id: 27853c96-0d42-4557-7da1-08dd6af20650 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|36860700013|376014|1800799024|82310400026|7416014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?WEpqb0lHUnh4NURzMXRYNVVCNHFvaW1tNEVFRjFmMk9JNDk1QWx6ZTRjUm94?= =?utf-8?B?SjdVU1UxVG1maGlqcTNldW4yc0MvWE1icFhqclM2QmRPakRRU0thUVZzRVpD?= =?utf-8?B?YWxTSmpBUG1ZTndZemdHcUpFUXBMcnJOMWlCWloxVjNma1JxbDVqeVBhZWtV?= =?utf-8?B?WlBldDBOWG9BWlJlQm1CRXF0SC9iZElRNGN6NytXYlBkNVJxWDZZclp6Yldl?= =?utf-8?B?bG0vcjFiM0o0OWN0dHJ4MlRFMUZpS1JNeGliTEkrclpFWVdodTJaRzNxNTRN?= =?utf-8?B?MVFrUXJycVJJbVJUa0p2Uk5NWVFlREpEMVc5TmxYNFJZNnY3QlJBZXlMdzhN?= =?utf-8?B?WDI4dDRVdXdrRlJjVERvWitDSTZxZWMyWkxramRuY3JCL2pEVnN5Y3VEbHRr?= =?utf-8?B?aS9QcE1OQ2lDQ21FcmxVdnZPN0tpTk1ObXhpUy9IY2ZHMGlIYXZ3NmkwZFpR?= =?utf-8?B?WTFHdmVBV0RNRVBZdnUrQUljWUtkRHEydzNJN3d1c1liTmJJUEMyMThaWnVs?= =?utf-8?B?cmNuMVVtUzF0UmpQMlJtM3dsNGdpei9LNWpUQm5aaEpDTGtaMHBBa0FqeTFF?= =?utf-8?B?aHFlYVF1NDRyajFFYVhyRlF3eXN5ZWl6THNDTDIzRUZjVGxsTC9UZlhkd0li?= =?utf-8?B?Nmx5TXA0M0ZXOEpRcTArcHVtZElZc1ZiQXhwdkVDUUROTVIvdVlpN2E1VFR4?= =?utf-8?B?N1dMUjBKVmRJbStuVHdpUnEvU0dhd0RPaW9EUDE4Rmx1QnJlZUFlK1htYm9B?= =?utf-8?B?UzUyVVIwaEtyNzZhcGZvc255WC85SklBOUJhNFpXZk9IRnNpSm9pWEw1bWpt?= =?utf-8?B?Q2UxbFN5UG82aitsZERLaUlaVnViamE5KzM3TUYxaXI0QmRxdjlCc3p3MUpU?= =?utf-8?B?S1RjbEtra3VyRjMzN3BWZE5OZVpXZi90OEdiT1NteFBsaTIrRm5NVkQ2NTha?= =?utf-8?B?T0x3eUNNOGllM1o0Ynl1c3pFK2xidC9DaTQxV09IQVZSZ1BnNHEyRSsvWjBL?= =?utf-8?B?S3B3Y0NzNHJobDY4VW8rRnluS21SeGgrREhZczlXWlRDTUo5dDBzS1V2UnZz?= =?utf-8?B?SXI3VXBJRFd6SnNEeWVFMExGM3ZibG1tUGUvQ09hYVd1UVlLRm5PS0pKZ1V3?= =?utf-8?B?aWNvVHBWRjd5NzRqUkNkYTNXN25EQTJabngwNzI2bEtOQlJhY2JPek94Y2du?= =?utf-8?B?ZzBNTnB4TEVLd2R1a2VCVmFJbmVIT21BMUlkcFNuNnptMG5taTZkWGxaSS92?= =?utf-8?B?ekxZNW5wbW15MTl5cjNBdktwM293TEZ1VDM4M21xWStXTU9GRzlWR3BtMkRU?= =?utf-8?B?TDhGcHJiU2dTaWxRazFjZEVXbjNiVnhlZlBwamlnVTQxZW45SzBtd3M3YWpY?= =?utf-8?B?WXdDMkJzU3RaTEwwanpUZDBLNWxBMVJiRnpudllCWHpENWJmb0FpSThXT0pN?= =?utf-8?B?MUdzemxiaFVSNVV4ejJkUEJEejU0RE1jcEFaOUlvNG4rb2RiQ0pQalAxVUtM?= =?utf-8?B?eHNENVEzTFZOS29SUjNKOTErZ0c4bXlmdjlrYjJWNFJLenQwdFo1OHJMcTlI?= =?utf-8?B?UUpidHJDTjBaY1kxWXlnVCtmL3NRSTUzQjZzRDJaQXhzUXVPaEdPTWxnZ1JZ?= =?utf-8?B?bVp2Z2NOZ0E3L2NPK2l1cktwdHJESEg3bFZYdiswOVQxVHVOV3kyaWQyQmRZ?= =?utf-8?B?R0ZaMnVOWXpEaFBLa0VCVnQrd1RCREIxQnhCZHhVWTJrdkJqY0JhcW5MUSt3?= =?utf-8?B?Y05KeE52dFBvbVJ6VG9NMWdRbnlsaEkwMnFDR0dHQitJam1uSk51eTNmYVhR?= =?utf-8?B?QjBvSTNlQUNna2c2VVhGMWpzQk5OL3hMblFMNTRGZXpnckcvRnp0OU5rZG9C?= =?utf-8?B?cTBoUG0vdVB0OHQ2V0hYcEJ6bFFXRk5wcXcrZUtDU2NPZzNlQ1NYbEdnVHor?= =?utf-8?B?dnkvT3lXc2U0K2kxaDBnMkFvb28rUncvaFplY1lUaU1GRHRuL1dVQVJHZjRm?= =?utf-8?B?blZYZlFRR1pRPT0=?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(36860700013)(376014)(1800799024)(82310400026)(7416014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Mar 2025 16:36:27.5640 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 27853c96-0d42-4557-7da1-08dd6af20650 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000E9D8.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA0PR12MB7075 On 3/24/2025 9:55 PM, K Prateek Nayak wrote: > Hello Mateusz, > > On 3/24/2025 9:33 PM, Mateusz Guzik wrote: >> On Mon, Mar 24, 2025 at 3:52 PM K Prateek Nayak wrote: >>> So far, with tracing, this is where I'm: >>> >>> o Mainline + Oleg's optimization reverted: >>> >>>       ... >>>       kworker/43:1-1723    [043] .....   115.309065: p9_read_work: Data read wait 55 >>>       kworker/43:1-1723    [043] .....   115.309066: p9_read_work: Data read 55 >>>       kworker/43:1-1723    [043] .....   115.309067: p9_read_work: Data read wait 7 >>>       kworker/43:1-1723    [043] .....   115.309068: p9_read_work: Data read 7 >>>              repro-4138    [043] .....   115.309084: netfs_wake_write_collector: Wake collector >>>              repro-4138    [043] .....   115.309085: netfs_wake_write_collector: Queuing collector work >>>              repro-4138    [043] .....   115.309088: netfs_unbuffered_write: netfs_unbuffered_write >>>              repro-4138    [043] .....   115.309088: netfs_end_issue_write: netfs_end_issue_write >>>              repro-4138    [043] .....   115.309089: netfs_end_issue_write: Write collector need poke 0 >>>              repro-4138    [043] .....   115.309091: netfs_unbuffered_write_iter_locked: Waiting on NETFS_RREQ_IN_PROGRESS! >>>    kworker/u1030:1-1951    [168] .....   115.309096: netfs_wake_write_collector: Wake collector >>>    kworker/u1030:1-1951    [168] .....   115.309097: netfs_wake_write_collector: Queuing collector work >>>    kworker/u1030:1-1951    [168] .....   115.309102: netfs_write_collection_worker: Write collect clearing and waking up! >>>       ... (syzbot reproducer continues) >>> >>> o Mainline: >>> >>>      kworker/185:1-1767    [185] .....   109.485961: p9_read_work: Data read wait 7 >>>      kworker/185:1-1767    [185] .....   109.485962: p9_read_work: Data read 7 >>>      kworker/185:1-1767    [185] .....   109.485962: p9_read_work: Data read wait 55 >>>      kworker/185:1-1767    [185] .....   109.485963: p9_read_work: Data read 55 >>>              repro-4038    [185] .....   114.225717: netfs_wake_write_collector: Wake collector >>>              repro-4038    [185] .....   114.225723: netfs_wake_write_collector: Queuing collector work >>>              repro-4038    [185] .....   114.225727: netfs_unbuffered_write: netfs_unbuffered_write >>>              repro-4038    [185] .....   114.225727: netfs_end_issue_write: netfs_end_issue_write >>>              repro-4038    [185] .....   114.225728: netfs_end_issue_write: Write collector need poke 0 >>>              repro-4038    [185] .....   114.225728: netfs_unbuffered_write_iter_locked: Waiting on NETFS_RREQ_IN_PROGRESS! >>>      ... (syzbot reproducer hangs) >>> >>> There is a third "kworker/u1030" component that never gets woken up for >>> reasons currently unknown to me with Oleg's optimization. I'll keep >>> digging. >>> >> >> Thanks for the update. >> >> It is unclear to me if you checked, so I'm going to have to ask just >> in case: when there is a hang, is there *anyone* stuck in pipe code >> (and if so, where)? >> >> You can get the kernel to print stacks for all threads with sysrq: >> echo t > /proc/sysrq-trigger > > This dumps an insane amount of stuff on my console. Let me search if there > is any reference to pipe somewhere in there. Only pipe_read() and pipe_write() pairs I found were for: [ 1043.618621] task:containerd state:S stack:0 pid:3567 tgid:3475 ppid:1 task_flags:0x400040 flags:0x00000002 [ 1043.629673] Call Trace: [ 1043.632133] [ 1043.634252] __schedule+0x436/0x1620 [ 1043.637832] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1043.642638] ? syscall_exit_to_user_mode+0x51/0x1a0 [ 1043.647538] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1043.652347] ? __smp_call_single_queue+0xc7/0x150 [ 1043.657072] schedule+0x28/0x110 [ 1043.660320] futex_wait_queue+0x69/0xa0 [ 1043.664176] __futex_wait+0x13c/0x1b0 [ 1043.667863] ? __pfx_futex_wake_mark+0x10/0x10 [ 1043.672325] futex_wait+0x68/0x110 [ 1043.675747] ? __x64_sys_futex+0x77/0x1d0 [ 1043.679775] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1043.684585] ? pipe_write+0x42c/0x630 <----------- here [ 1043.688269] ? copy_fpstate_to_sigframe+0x330/0x3d0 [ 1043.693167] do_futex+0x13c/0x1d0 [ 1043.696501] __x64_sys_futex+0x77/0x1d0 [ 1043.700359] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1043.705170] ? vfs_write+0x376/0x420 [ 1043.708767] do_syscall_64+0x6f/0x110 [ 1043.712449] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1043.717259] ? ksys_write+0x90/0xe0 [ 1043.720768] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1043.725579] ? syscall_exit_to_user_mode+0x51/0x1a0 [ 1043.730475] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1043.735288] ? do_syscall_64+0x7b/0x110 [ 1043.739144] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1043.743953] ? irqentry_exit_to_user_mode+0x2e/0x160 [ 1043.748935] entry_SYSCALL_64_after_hwframe+0x76/0x7e and [ 1048.980518] task:dockerd state:S stack:0 pid:3591 tgid:3582 ppid:1 task_flags:0x400040 flags:0x00000002 [ 1048.991569] Call Trace: [ 1048.994024] [ 1048.996143] __schedule+0x436/0x1620 [ 1048.999741] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.004554] ? get_nohz_timer_target+0x2a/0x180 [ 1049.009101] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.013911] ? timerqueue_add+0x6a/0xc0 [ 1049.017768] schedule+0x28/0x110 [ 1049.021017] schedule_hrtimeout_range_clock+0x78/0xd0 [ 1049.026088] ? __pfx_hrtimer_wakeup+0x10/0x10 [ 1049.030470] do_epoll_wait+0x666/0x7d0 [ 1049.034245] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.039053] ? __pfx_ep_autoremove_wake_function+0x10/0x10 [ 1049.044556] do_compat_epoll_pwait.part.0+0xc/0x70 [ 1049.049368] __x64_sys_epoll_pwait+0x83/0x140 [ 1049.053746] do_syscall_64+0x6f/0x110 [ 1049.057425] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.062235] ? do_syscall_64+0x7b/0x110 [ 1049.066079] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.070887] ? do_futex+0xc2/0x1d0 [ 1049.074309] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.079120] ? __x64_sys_futex+0x77/0x1d0 [ 1049.083151] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.087958] ? current_time+0x31/0x130 [ 1049.091731] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.096539] ? inode_update_timestamps+0xc8/0x110 [ 1049.101264] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.106074] ? generic_update_time+0x51/0x60 [ 1049.110365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.115173] ? touch_atime+0xb5/0x100 [ 1049.118857] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.123671] ? pipe_read+0x3fe/0x480 <----------- here [ 1049.127265] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.132073] ? ep_done_scan+0xab/0xf0 [ 1049.135757] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.140567] ? do_epoll_wait+0xe1/0x7d0 [ 1049.144425] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.149234] ? do_compat_epoll_pwait.part.0+0xc/0x70 [ 1049.154218] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.159027] ? __x64_sys_epoll_pwait+0x83/0x140 [ 1049.163577] ? do_syscall_64+0x7b/0x110 [ 1049.167433] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.172243] ? syscall_exit_to_user_mode+0x51/0x1a0 [ 1049.177141] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.181951] ? do_syscall_64+0x7b/0x110 [ 1049.185811] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.190619] ? ksys_read+0x90/0xe0 [ 1049.194025] ? do_syscall_64+0x7b/0x110 [ 1049.197877] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.202682] ? syscall_exit_to_user_mode+0x51/0x1a0 [ 1049.207579] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.212391] ? do_syscall_64+0x7b/0x110 [ 1049.216243] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.221053] ? do_syscall_64+0x7b/0x110 [ 1049.224900] ? srso_alias_return_thunk+0x5/0xfbef5 [ 1049.229703] ? do_syscall_64+0x7b/0x110 [ 1049.233561] entry_SYSCALL_64_after_hwframe+0x76/0x7e -- Thanks and Regards, Prateek