From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=pass header.oldest-pass=0 smtp.remote-ip=40.93.195.6 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=pass; t=1792485931; b=KmqUMsm3rzN2d7g+AjFbj82WdWK7b38vxeMOuPKzPhItZyjV7UzHFQdbUZD5bU3hKQ4L ckeUDIGSIk7zwp8ytjY/kAoYbi2ypmsP5tDDrn4+WqFHvjY2Cyvut7EMLCRPfwJsDn90e Q5RIxA/RTvbarWImwuULd8jKi8YVzaxB7+8pAHITqXBmhupPMGYW8BqKkL3VJK48gINC2 juCeDdaZMtTerlVXcZJ0wOVXkAZLkEuTz1wtA7UByLt7JuGV+gk07EK/pW4ESqKSeBr32 /3qG12kIWmExsWo4zN2pDw6PCfz95gWJ7Np9bPKp8QFZPcULISTzQzJX00bSAE67Zwg== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792485931; h=DMARC-Filter:DKIM-Signature:Received:Received:From:To:Cc:Subject: Date:Message-ID:X-Mailer:In-Reply-To:References: Content-Transfer-Encoding:Content-Type:X-ClientProxiedBy:MIME-Version: X-MS-PublicTrafficType:X-MS-TrafficTypeDiagnostic: X-MS-Office365-Filtering-Correlation-Id:X-MS-Exchange-SenderADCheck: X-MS-Exchange-AntiSpam-Relay:X-Microsoft-Antispam: X-Microsoft-Antispam-Message-Info:X-Forefront-Antispam-Report: X-MS-Exchange-AntiSpam-MessageData-ChunkCount: X-MS-Exchange-AntiSpam-MessageData-0:X-OriginatorOrg: X-MS-Exchange-CrossTenant-Network-Message-Id: X-MS-Exchange-CrossTenant-AuthSource:X-MS-Exchange-CrossTenant-AuthAs: X-MS-Exchange-CrossTenant-OriginalArrivalTime: X-MS-Exchange-CrossTenant-FromEntityHeader: X-MS-Exchange-CrossTenant-Id:X-MS-Exchange-CrossTenant-MailboxType: X-MS-Exchange-CrossTenant-UserPrincipalName: X-MS-Exchange-Transport-CrossTenantHeadersStamped; bh=lhpIxR1TBcCZ6Tp+QskSkT6XixwZnSAQczofNbs1mFo=; b=Swwf0oZ2Mq76X8PpzKjLzkuBEFX9k7L4IU5waK/1duQ460dJm+5wlIlRMJ2CRXPodavl 35PWNVOwBrNo5srFT5WIyxgBlQ9GGl/Vy9/jogLKZ2TioBvdZRZkG2z4t7YlwSVDmVugD MaLEiyblpRChiXbhrnYnD4DLxWLNVUdWE3Oazak9gmcOSJLa4sEpiBG1uXdtBNB2wzm2h V+IYoHlBBTLZFcQzatpobVgjqmAc2Nh+cs87aELjWU5hGNhBwbsDMNk4gLIbnx+bCFqeH XobBvX3r7sTryrA5ryybcnREVVP2Zdft2wSs0z0z2keu6x/8TAsAvAjUL4RnUN2jjCg== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=gOalHrKR; arc=pass header.oldest-pass=0 smtp.remote-ip=40.93.195.6 Received: from SN4PR2101CU001.outbound.protection.outlook.com (mail-southcentralusazon11012006.outbound.protection.outlook.com [40.93.195.6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (secp384r1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5BA85606A325 for ; Tue, 20 Oct 2026 08:45:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 5BA85606A325 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, unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=gOalHrKR ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=b/CfrXaqTXiQTSIu9ZdQXaxveInaohZRX0qvmsVPnOFGyEY424vzusXs12Eyqqbnz1mhpGz+B1aNM2DXMhKIFj+bR4ywSrFhcdfj3NaXzaQu4KVC2SCOu9c1AdUyQGrwx1k+/aAeJvVoiBpngA4ZWgK7MqT84fujobaOd92XnwMMwprG584MSFYyhBlWBeLOPg3FfPLyLBy2J63tEad3G5pFBXh+E7vw3Yt8qTEkymEQMSAqbebuSTtdeqBIanj749tnacrRwi+/TzDkRrC9TntW9IE7SmEPqY7NAmOGPVRzPp+UovY9IgNB5szrOTMbuIB6UKP+Cx3jqID/Wum9cQ== 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=lhpIxR1TBcCZ6Tp+QskSkT6XixwZnSAQczofNbs1mFo=; b=Mv2QBOOAsza0uGaFk9mZYBatAcTVRixQ5OI/adx8u8ZsyUlS9lSbt2E9PnIMMWn//BLRr34eEjspiNGoVhlsLdTkSwsJBou3G1Ti8GbyEqEtOs5hdl6AKTxCkRHW4R4o5P51ckczon+DFUVHKYMuY8NgdSm52cyLlSTygJIGSh+3r3kn/YQZC6g24LYntNBKuIKV8LHo6+hVwa2cI4pM91YsivW84EcxNhhmf4BPY5ggJUniXycZCWqtVdhIs85psSNmKiy6cRoFF6cLN3qs0dPB0DX5k+dhz7eL4GKSUwjVqL0lN4uoiWsqajWNrqcqniMNbCt4ENj4KWy1vi8zCg== 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=lhpIxR1TBcCZ6Tp+QskSkT6XixwZnSAQczofNbs1mFo=; b=gOalHrKRr0G5z0IpajpBkRl/ndYinnwKDzFPTpC8P8iTTWyC3GeMcU+SrL6mkN+taY5Y8cRlQX/BpQOgz+HZIZT8SWTN1ZIqDvAb9RbygpQ70wuZG60GH1b59topOUHBS9od6eYyVwgTwKv7FA/dXXSrq93ZYVufXWfFvaknFWQsmvARTO05m+j1N5oCV/WwV8efhNiQM7MYmHF0ogvZY0tzVZMmGe7U6xaZQy8x3s7S+f/uscb3+8A6xbAeWPGN24d1yy4ukeCsm2GLJria4dJX/1fbdtEeiA9U0Njc3lqjjce6I1j8Jyj/SYNrcXblMgD0IqS2G4RoeHeRY6cUxg== Authentication-Results: mx.microsoft.com 1; dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from BL1PR12MB5174.namprd12.prod.outlook.com (2603:10b6:208:31c::19) by CY8PR12MB7220.namprd12.prod.outlook.com (2603:10b6:930:58::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.522.12; Tue, 20 Oct 2026 08:45:28 +0000 Received: from BL1PR12MB5174.namprd12.prod.outlook.com ([fe80::58de:822b:868:96e9]) by BL1PR12MB5174.namprd12.prod.outlook.com ([fe80::58de:822b:868:96e9%6]) with mapi id 15.21.0546.012; Tue, 20 Oct 2026 08:45:28 +0000 From: Andrea Righi To: Tejun Heo , David Vernet , Changwoo Min Cc: Emil Tsalapatis , sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 3/3] sched_ext: Remove the foreign CPU check from the kick_sync wait Date: Tue, 20 Oct 2026 10:43:21 +0200 Message-ID: <20261020084400.845842-4-arighi@nvidia.com> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261020084400.845842-1-arighi@nvidia.com> References: <20261020084400.845842-1-arighi@nvidia.com> Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: GV0P278CA0071.CHEP278.PROD.OUTLOOK.COM (2603:10a6:710:2a::22) To BL1PR12MB5174.namprd12.prod.outlook.com (2603:10b6:208:31c::19) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL1PR12MB5174:EE_|CY8PR12MB7220:EE_ X-MS-Office365-Filtering-Correlation-Id: 1ee56b97-5ccd-4b11-46d3-08df2e867dfb X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|23010399003|366016|10067099003|18002099003|22082099003|11063799006|261009223027099003|56012099006; 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:BL1PR12MB5174.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(1800799024)(23010399003)(366016)(10067099003)(18002099003)(22082099003)(11063799006)(261009223027099003)(56012099006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?+onefcKaS1ro2vzMGWuRIAkE/8L7aBZ1k77E+wQcMHALvsEB7GgsqYiGAUbp?= =?us-ascii?Q?xSNl6N7uFcu0DIWzjpWKEiOqpsu7eDELK/AHnRP3BDvB+4zeEiJsXEEqV8OS?= =?us-ascii?Q?YPMTcp7RI4rz+PQAJKvzqlXenQLHLmdjWUxBGrdydJbSwKaIlwQxvmSO20jP?= =?us-ascii?Q?9m2mTMESvovHS4d+/tny9E9F7vVVy06m0bKryHnVkCJaRzqAF2SwxfAnAPJt?= =?us-ascii?Q?OmXrd+JdD2VrD+eEo9Me5yapNwE9Sy9YOaemKCdhfaMZglJsIuojW8OW9CjB?= =?us-ascii?Q?tVrvhMTpHXuYkiqY+DPxNbWvym/9/i4ZLEUXeHmabIR2a4gCDggkczIo7KVY?= =?us-ascii?Q?MzLLXmaesABI8OkU1ScesIV4BfkWdUFYA0H2ZifHbmLcU5uL2dQVGTSQT3eh?= =?us-ascii?Q?8hzDW+27+2bgqygTNgIaHzcYrEtQiObnfHpnArX59SjWvi87ORD6LQ6ZEUtj?= =?us-ascii?Q?eEJ+e1XwK1iYSvo/nzG6qRkW44urSL53alqjLbncg/Mcocys1fq5WibeqklO?= =?us-ascii?Q?wDH40DzFubEEYrGDUZxcqhkyHjWVpJnI6XZdwvcVThlwYDQmB4YcdjTlsLaB?= =?us-ascii?Q?GTsoI5xoicPI82pASzFXQ8cUVFVFIJuhvFEtrRy9i0crankJa1Pc0yVoiaKL?= =?us-ascii?Q?fYBx1i2PWUI2Ly0qIsAgNlXK1FR5TIju875ko/MLsV2CGytNI2b6q4OwTIhi?= =?us-ascii?Q?pWUEd9FeVmiEOp/2cH8qWOCt6OiLd+N5iCnJCFBtnvXgHpiKGz32Oxcza5gP?= =?us-ascii?Q?9sSUnLoKIKbjAekuP78B+poJMx7pxesz1jtF/nSjjvU0uilJJhl9nUG7IK/S?= =?us-ascii?Q?bEbJxHVDYZAhFnY7t0dHwmqmQia9V2m8N5l86hLlR6+l9q/XpThuJAxwFJ41?= =?us-ascii?Q?wsM7k0jELo+qojx9qw2Br3enrBTU8TKAJBd0dkEM+gHVdTx77l25QjcMkMPV?= =?us-ascii?Q?WEVcWORiMT5koRDzEXtK12heqx9uO1Tm5D6t/jaX8z/azR5AxhJiinglNp2p?= =?us-ascii?Q?wlAJ9EMIb/hZW4axM/eIFwmcPNm3ZKttJeGayonMu9P6eGDOhAAyKy7OPGI6?= =?us-ascii?Q?S9Zrr6hKIW55vEIWQi7MqYlrk998/SAzB+4i+AZ87UZzPpt2N+DWBPIVhl9V?= =?us-ascii?Q?FAfCWD9iEMbv/Yq+Oq1X4y4LLh7ZGR90hsvNf82e533Ll0rhmbFjnbSoRwVr?= =?us-ascii?Q?Oiw7A1wYBiwnkRz02TUHlaHZRaB3Ve7nu9DvoKfeAHBAIAiW6NSvzs4fILFg?= =?us-ascii?Q?gRLkcRvFK1Umd/p716QCw0WsR2sb88wwaLBMKgBDWOlqwzcIF+aPhLPfNLon?= =?us-ascii?Q?1B3tv4QpOYRJJwDqur9Hrnj8YfjgVm1z2EPpSSFKL2Mb823ahnjFZzgbHG2P?= =?us-ascii?Q?DkZ43J3ZXf/Z47Yd0Whoq8vNWMhZVUC2pDeSjsTY4UpxF1YhGV/7IIyxA/Ix?= =?us-ascii?Q?05Nnk1H0NRqTNWU6oSrgpK/O70+KwcbcNmckvwKD5mF9CB+0d2uPXFcYJftJ?= =?us-ascii?Q?rYPo0XvUY009SVO5+BCgjkiLZJbl+RR4h9CQfQtbqrJjgFOK/GRmcUtWQ9wo?= =?us-ascii?Q?vQQ+xt9JpnVW7WbUYLahOokXwO0PenQ3Qf9owadTQaTwZsVL5ZDRx+zdhYkx?= =?us-ascii?Q?jmNyNKYjCbjUEJN9n9m9BOuS1tJJ86q/NGDH3e/QuVIya09GPfctH54glb3g?= =?us-ascii?Q?625JjdfFmn2pAxK+CoygT4Hc4e6sGKWQtVDiH3DGLE8I4D8/?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1ee56b97-5ccd-4b11-46d3-08df2e867dfb X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5174.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Oct 2026 08:45:28.4673 (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: pT2SYqHtIjL0auMO/71IscKpLvDWDAZvblIJWFU05WWkaJ3ST9hPpV/K2NLSrPgahtsU2zbXHxZ/szlA5+AOMw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY8PR12MB7220 The kick_sync balance callback is now queued from set_next_task_scx() after the core-wide selection has finished. Proxy resolution zaps the callbacks before dropping the rq lock, so a foreign CPU cannot acquire the lock and flush this callback while it is queued. Remove the unreachable foreign CPU check and its obsolete comment. Suggested-by: Tejun Heo Link: https://lore.kernel.org/r/08cac02c604dd73ef96fc92eb29d692b@kernel.org Signed-off-by: Andrea Righi --- kernel/sched/ext/ext.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c index 4b7d2602b4d40..a9b26fa431bf3 100644 --- a/kernel/sched/ext/ext.c +++ b/kernel/sched/ext/ext.c @@ -3733,15 +3733,6 @@ static void kick_sync_wait_bal_cb(struct rq *rq) bool waited; s32 cpu; - /* - * This callback is queued once the pick is final and flushed within - * @rq's own scheduling pass. If a lock taker on a foreign CPU ever - * flushes it, the snapshots are unrelated to that CPU. Don't get in the - * way and leave the wait pending for @rq's next pick. - */ - if (unlikely(cpu_of(rq) != smp_processor_id())) - return; - /* * Clear only when the wait actually runs. The callback can be dropped * without running (e.g., proxy exec zaps the balance callbacks and -- 2.56.0