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 502381F03C7 for ; Wed, 8 Jan 2025 09:05:44 +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=1736327145; cv=fail; b=ElUlTXd8QQLTxj2nZLBoMM7qnuz3baPskU6bqvcLOnEcJNyo5sR21KmOJWSMm8QqTPDw+V2goldwD0fQyw7leBZVy22Z1oQEPFQD7ApJe/ANlycaRQ8wf6prr/vH/MJ8EmQB53G0ZZ3N/ZzKHCyf0/9buJxZtbQqi35vyfQ580M= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736327145; c=relaxed/simple; bh=ZnJ5N5+AscVIsRTeVstwZtiwPnSRQpQ0/49tHSMYfq0=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=e0dYvHZBu2a8xceDCVNMNDxA2LXesl6ip0okWVuePcGQSz6CY1F0CTj7i5RHvRcspGYz04KzUFKNyXEHP2NQ+c8xpTctvJqBhwEX+kr9ELROIM2c+SA3+ofNYy1YQRCBMhdza3dEen2b6DQIdnKZqFWe15EGb9sLJjWLvWXt+Js= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=Rt5qGsNA; arc=fail smtp.client-ip=40.107.237.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="Rt5qGsNA" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=lSLhrObuBspVC+yy73We/nC0rGHub/CdAu/18X7hosHHk3wnTyAPeR32SKZLOmmP7tKezL0OBbGq00xXyV5CeX2J3JHkY90B3dm7fTcRUXRcW/rJ4CfrdnBDtUZkpuKOdslEEsXo8p5vEuZWJ5vmHoBuQdF0uReuV3dabMkjkV+cxHJsu7BTAGBZMi2846gE64bfne+wV0heiJb76G3736OAICKhD+LBMw57aUctbuOqK9XozCunwXTaGtxOn1E2zcWZ2Ca23uZsWVpJkYRDxNKVUKZ38HKnqm2L5zAr1NpQuZsgMum6rO63VTc7nmXrs8tRIuga/oDly1flHLNhcw== 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=gsVXENWeGHGWfxLAupWXmq1H1cG9WAEUV0b53dtcxbM=; b=CU+//GzHvUPaT2fCnlg3ivax3xCamfcXEs6IrCM6DypC4e2cWUHzv1dfN42/7PYuUpitPG+DXJaq03zDEhC+tdb/EVw1+bh783Oam7sauOKSdOBpB0ZaT9o/VYK2jixX7cxq0ltYkMF2Mq76KMjRDCA+MouHV5yQRUG12KtEDyGpTL9Ey8JfG6frrDyGOVpVoaV2wPrbvGP8jKeuClAAKtw+mcoI2rIb8kQssV0x9yPBQureH+Qc1/6yv7fOcps8XGTX5i/KskAwKQ6u+Ci4CcOl43VjUyTn8FLn+yIncGCkU5l82U7cxcFTj3nEtU1Lt60rEyPtT2IUPwXrzPc6Vw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=gsVXENWeGHGWfxLAupWXmq1H1cG9WAEUV0b53dtcxbM=; b=Rt5qGsNAhvZduzgLmDxnPYwHMtV9V5cc/2D4mAXfP04qV5T6d5S5yRwhulkiS83LrgIYW129YkUcd5Cg5jhkBzs5Z7Wr1a4YPlbv6WTPpQUT4hQ8XXgoP1Y6DOM2EyXHtSuTjuiNKaUEAblSXPo+dAVhwmhkjW9T0GN5ORiInD0FleazPaV7cPqwmp4NvZjdUy8YxSN5ttwrNNkemPj4BhqOUGOo/wt3CdqzNSKj31Jymt0MJ1flRleJ7fgRMGOcqyvrf5lY7/47DREah7L+jnwIWL9nv3MzSrLqbzJ2VathI0opAG3BfKiUL5e8jLpiD30kEXkJKwzypQqVUM7ehg== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CY5PR12MB6405.namprd12.prod.outlook.com (2603:10b6:930:3e::17) by DS7PR12MB5816.namprd12.prod.outlook.com (2603:10b6:8:78::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8314.18; Wed, 8 Jan 2025 09:05:37 +0000 Received: from CY5PR12MB6405.namprd12.prod.outlook.com ([fe80::2119:c96c:b455:53b5]) by CY5PR12MB6405.namprd12.prod.outlook.com ([fe80::2119:c96c:b455:53b5%3]) with mapi id 15.20.8314.015; Wed, 8 Jan 2025 09:05:37 +0000 Date: Wed, 8 Jan 2025 10:05:32 +0100 From: Andrea Righi To: Honglei Wang Cc: tj@kernel.org, void@manifault.com, changwoo@igalia.com, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] sched_ext: switch class when preempted by higher priority scheduler Message-ID: References: <20250108023328.37675-1-jameshongleiwang@126.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250108023328.37675-1-jameshongleiwang@126.com> X-ClientProxiedBy: FR4P281CA0094.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:cb::11) To CY5PR12MB6405.namprd12.prod.outlook.com (2603:10b6:930:3e::17) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY5PR12MB6405:EE_|DS7PR12MB5816:EE_ X-MS-Office365-Filtering-Correlation-Id: 4725c901-055d-4438-838e-08dd2fc39e07 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016|7416014|7053199007; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?6Ht7ROaFc3asHvQXGgbR70iM6mFSJtEVnlZkzVqwbVcy838+1P1WQgAndYVS?= =?us-ascii?Q?+Cd6+lgaxXfK/mNmqDUMtgKkBqLSZVPW2Pn+2Wu8mmO+j4tqZGb8cFQAp/3U?= =?us-ascii?Q?Irjnj5WjRfTux/I3DLlIVgnNl1oGoQwyo0yNe3VJMD4yPAWWqqAGm0zsWFjD?= =?us-ascii?Q?wX34RV+oHNuvJpdbvNTyce/GzOlydAYBEPUz8gMnAmSiNQbwnQ+qvtUMdlo1?= =?us-ascii?Q?hn36/b6u3P/CXsVlmmtab8bEuye7/xKCinW5eTbmbawUJFPUS0ekZwKBzalH?= =?us-ascii?Q?ka9y6YW1tUa9ueqYpOjh7fWPDnbdrqaMsapaNaanuag1saPo9Z0t5GwMYX4W?= =?us-ascii?Q?vSbKh1BhXj88hZ3R/rirpwxbiUqHbQdOwy9NZifchB9bS7vZL8YEN8P/7Wjd?= =?us-ascii?Q?JqEp4MTzFWL7uQtYUYQLhcnV2SCTYzN2exqZdwUKQrTt1pA+NDRrQYBpZ2KW?= =?us-ascii?Q?vRi0wumdOyEo6HqzsLFI00s+DZmZMJ5j9c+p3Qbz0qfvwOEGp/3Rpg2l/lxl?= =?us-ascii?Q?OJTqe4oomFJ4e5GC0GyTLLTv+xiVpLQXX87HwfwhtQ9cPW/VYTNshGK/6zJ0?= =?us-ascii?Q?b8XkAbmlxO783Tc1tlYJLU0Cdk1XKC2PqCvaMvxGuZZVYOKHCbu3PI/VhwJW?= =?us-ascii?Q?u8mQQdShFHlFgBhAeerPeaf7iy7Y28n9bZxmcaqJ5EoJP+KwuQQ3xNdrtRGd?= =?us-ascii?Q?A89J+EtsTOKosbR3B9oiegjw4ejH389K0GDTee9qgLWQkNa5+pPz8bNw0PcS?= =?us-ascii?Q?s8a2+a2hb5QHUBY9V3UUkFl15hklijqJeK2ca0z0uANsKZH2MlX1UXerotfy?= =?us-ascii?Q?gdhMsUVCBP5dAD6ItWeIgtjikBycsAaVjL1oEibl0S+bO/+VRxDkYyBQ7lti?= =?us-ascii?Q?lZpgQLGLJyHM4re+aeyqre+wq9kmFP/8GxsitMiHakgrTRJglzs1JwH1vMg3?= =?us-ascii?Q?TT7tK2IGjgOxHkHSHs8EeT46tbULYReUr/VjCBOwFhtzD0SR/b7MvuhQUys9?= =?us-ascii?Q?lWpIM5Wax35WAC8x+HdfpsLHRswgng769Zm3eLN1y3M62jiGsvJUL3jbK1uF?= =?us-ascii?Q?0uZX7bGJQs23B8IHRjuu38ea8rPiI9bfv3w/cUF5K7BnkOlllNr/rSkQVPX1?= =?us-ascii?Q?i8sFVzdgpDY+Y/jDOSApq2tV8fGMYdoBDJH/RlhXGAo8+6Qs/mSQhns5qQhl?= =?us-ascii?Q?BgKpgBHz/o8w/jWpTc97y1ep9h5l5SoA3rV4toaQ4zBEcGl4sE7swpSiwSSt?= =?us-ascii?Q?FyNM6MJora1QIXrO08BwTOh8pyZ4jnYs4OyAMzf1WvxX+AWpDzZr+pBSIZ2M?= =?us-ascii?Q?b1OGOUGeIk3umreoBpNr5MW0Rwi14cndDSsWJm2TWCgHkYRyY3VkIWMb3ESm?= =?us-ascii?Q?wOJaGkMZRwUvePyzYT8mH7uBHoLD?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CY5PR12MB6405.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(1800799024)(366016)(7416014)(7053199007);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?OCPPudrt2tEgDvLqEwdZNTM7A0B8EoaFtlOAQdCWBB24HpPBqS/KcbVb62F8?= =?us-ascii?Q?47+jj7s4GoEFk7jwZkGgROFTOgfv2i/GGBZRKLhulsmtQM5O6BPG/LQItq8S?= =?us-ascii?Q?d44UNA7gUmj/uyTxvPhlEwS7VIy6REZtUH30dP8NmL6/ulyWMBv6ttugqpzw?= =?us-ascii?Q?YMIQAA31Xi9+VpPXcZdMu5ksPCrQejTbyhP9IkuvdxBum2tN5JZLU+PI4EMA?= =?us-ascii?Q?ybjrnYTOdDTiSQtL2T1eWshtsDoMAF2FFdu4lIWQj/fkDL9Ad6wLQ5dmWlK1?= =?us-ascii?Q?0vC4ONPk3rUn3VayVwH7TUWBvcKhIDFcqdZHRqSi4//mgIctTm2a7f5AwsBL?= =?us-ascii?Q?3isyBAVf8okBwb2b5iVSyeGB1/jaa20pkM/SJ3AQCrZDsNufCiYO3octV5NB?= =?us-ascii?Q?PWT8KTLkGmOtn+zklz7ENtuqaEiKRwmOiCGCmrNDpcf9BBIDBEkf1ebRZNXh?= =?us-ascii?Q?Lr4N6unxP3j6AbzwjGNpikfrR8NERxML2j4xstG2hUakvYdDcRY3MRjMQ7NX?= =?us-ascii?Q?LgCMdUJ+qkZ27mbU8e+19rvdZH90TkCEL2rndGONULyVJy7v+GOcWyzq8O9W?= =?us-ascii?Q?YggzfGeg8SXFDeX3bOi8tWUU+VZuh+EPRzb8DINdY4cN7Xyi3FkkZhiriP5Y?= =?us-ascii?Q?vALObsE5b2vP+dlW95+1dWaSZe6qKX9BIjh8f+5o4dBJLgD0cfCWKpO9b87N?= =?us-ascii?Q?jB+HYuO9ulD0F5seRB4XGwIHRsJPBxqwtywy7X1sFM/ubvn3O5JCDNZXWVP4?= =?us-ascii?Q?xAtX9E5Lf1AcUO+/X820iEYLrTo0PJ4fB63d1nXWdzuUGndDUyZT+POfZwSV?= =?us-ascii?Q?O5cwZJjD7GHIfuivlen9GfsdUPbb//i7uanrhSKUTna8I2iQCY2Zbcb06OCE?= =?us-ascii?Q?hpa304C7iMZ38NhiLTgxISG1XbXr/Qlyxb9UOsmy5XsHfBbmovmExovUaN1s?= =?us-ascii?Q?5x4DloiQPIFfSngd1oRWb4CqkqrTxclUpeX6sWx2XHaaHEtBpzwBYjwCfsVx?= =?us-ascii?Q?JyEQwf/Idu+KovaO/XuYlG5Cdgd+Q7BYiAvx+dar9QkcbvbIJgeADRHa709u?= =?us-ascii?Q?uGCW1aKqeApVywBEGwLPEmXX5o+jwJwz+MgFnwg1vYkPhsuTBbCGMBV5a5KC?= =?us-ascii?Q?BSzjYzBB51mFoMENYtTOW/WenY0OU/2jSO4ovwNQYIpym6K+ff5qljt0IEwt?= =?us-ascii?Q?NYCtMs753hZtgjSJ5vw25FA6Vxqpnmn34HhBrSR2uFI6vzk3lWCSx9R3HWhb?= =?us-ascii?Q?Age+yEE92i4RetlyNoXv42Va5YCr+KE5FM6VwlFm8qGQGR2DlksVUL6C7Qz2?= =?us-ascii?Q?OjD3XZnNUj+BcM02t1m87Cnd4NIfVy6CmK3AbG5HDjpJboFf5Y4jJFU7oDpC?= =?us-ascii?Q?kspPXxf3rjJNrxiG8STAyzFAXDI4GXUowaVBRl4gPkVXYiixYIm7liuzLZAl?= =?us-ascii?Q?Q6WuunAuKBm6CAVeWLpTmGPp5PX6M2pN8W/syDYfO7s0oVzbmIgfZ1B4IU8p?= =?us-ascii?Q?D8oI+WCKS/b0YXWWcQDef3vYYhEiEYI2fovljKLD9I8maIHUAKeVL7MYachg?= =?us-ascii?Q?3R9w87lUBhaXVXFclqwUGOL+GKx6G7R6GXKJI5W9?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 4725c901-055d-4438-838e-08dd2fc39e07 X-MS-Exchange-CrossTenant-AuthSource: CY5PR12MB6405.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jan 2025 09:05:37.4385 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: uLvfcyJycnmA9mcvXMzR8XwTZGrMIJtSQqxjktrZm1GE3kLc512OCYhniRsSdlSVr0M2IzqpTghsleCM7wHdpQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB5816 Hi Honglei, On Wed, Jan 08, 2025 at 10:33:28AM +0800, Honglei Wang wrote: > ops.cpu_release() function, if defined, must be invoked when preempted by > a higher priority scheduler class task. This scenario was skipped in > commit f422316d7466 ("sched_ext: Remove switch_class_scx()"). Let's fix > it. > > Fixes: f422316d7466 ("sched_ext: Remove switch_class_scx()") > Signed-off-by: Honglei Wang Thanks a lot for catching this, I've also reproduced a stall (due to the missing ops.cpu_release() invocation) and verified that your fixes resolve the problem, so: Acked-by: Andrea Righi > --- > kernel/sched/ext.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c > index 19d2699cf638..ef0e3f2c1e6f 100644 > --- a/kernel/sched/ext.c > +++ b/kernel/sched/ext.c > @@ -3034,7 +3034,7 @@ static void put_prev_task_scx(struct rq *rq, struct task_struct *p, > */ > if (p->scx.slice && !scx_rq_bypassing(rq)) { > dispatch_enqueue(&rq->scx.local_dsq, p, SCX_ENQ_HEAD); > - return; > + goto switch_class; > } > > /* > @@ -3051,6 +3051,7 @@ static void put_prev_task_scx(struct rq *rq, struct task_struct *p, > } > } > > +switch_class: > if (next && next->sched_class != &ext_sched_class) > switch_class(rq, next); > } > -- > 2.45.2 > -Andrea