From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from CY7PR03CU001.outbound.protection.outlook.com (mail-westcentralusazon11010063.outbound.protection.outlook.com [40.93.198.63]) (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 BD96A3AEB4E; Wed, 29 Jul 2026 05:26:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.93.198.63 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785302805; cv=fail; b=Oe9AoVC55x5aRmZHTwkqxWy9HMsTjN5ZRt4PwtsT3KOESq+IUydeB6P/g/1n/mEhzCMO5/DAVLHUkpEYiOd7Q6wcF5W4rPNcsRvnJtpx/26ioqYZtUHhU8we0YVj82K4rbD/HKPMIz1f0K4uPccIntS1Oyp2qZUxBNiF8VEhbbw= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785302805; c=relaxed/simple; bh=yQicfbgaSCluglKDhDObJ7/KwqzLWTLZpYYaRR9iW9g=; h=Date:From:To:CC:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=K3y8sS696nVa3Vi2skge97f9U/AbadfxokfDEulAfZgUfxvT0QM0XH9HQ8rDDpfxpuQmQZXwmCMAEYeVhMwUeO5fMmVtFU37fEYWpj/zMGedS/VtYUe9dgjd8tXUSyTDGdKMQxe9wCl0QNOBtXYArVuVAymuDhTfmvJBkU2sKmM= 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=XiJj+V90; arc=fail smtp.client-ip=40.93.198.63 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="XiJj+V90" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=kK/xPc0HvcIojHuGsZ8k83UqHbdHy5fTiiy8L9DC9RNJ+gzBtDr/mYFTgf58hHP5PcKjBpZ0m/6SUi//3fhmdHNNJ/4a0dHm6Oaf9i1CewSVEm7aYbcZV1OM95kzDgdFEAWLdDcAePXlc7HJWY9QE0sRlnEEkGBKjfrmgppPhtkYDAPS52lRpIwY+PtStPyTda+2Vy2YwreW78tuHC0AKdyZDLkemDkCztqtbLATCS27g8eVcDUZlwvA3iUVeLE0ORNZbeKW4lL7XoY87voe40qsOdqbBlNxfkEWTmgri6PSAmD+eGyQkYLV/fHuJK+dfapUYbcJ9HmfM8c47PsomQ== 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=Mtcgp/MWEP/ogAbZzZ1iSHLmhy8pbnK4i1R/lEsUyDA=; b=nDG3e+HVL2M74n/x4/5juTVm92hoLT1xUgwI5QFjXW3+U9KSEpask+MlC6UTVnEAaF6qjdAiWV3mGTivt1XbXzCK6f0VT9VSWpIZ0ZXH+OuJJwWfgig08UyyIZf1wxvcRw4ZOctX7JUaIf5uMEomVC0TGj5RWLWqUWwF1I6g4qDbBhVUDTHFP9jydpAXr/D+5i8WB9wJYbH1gdPBHJFfyXTkdwf46WKkdsXrWC0+O6lXMpIiaceacLPcfFTwSdOeZD6oZgqIgYPat8UGoWDFyrc8rL5V7psS2Nwioy5hbrnxL4X0nDo6cg97+vvefFMrm8+qi+rK+yOhPzT7dkKRyQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.117.161) smtp.rcpttodomain=google.com smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none (0) 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=Mtcgp/MWEP/ogAbZzZ1iSHLmhy8pbnK4i1R/lEsUyDA=; b=XiJj+V90xh0HfEEI40yzWmZ+oFMOMVHE0x8ZHWFesdm7jhkSr2Pj00WpJXX7kGncJEIFZg8mjk+vdo7pdZXIOQZyHEs/e0AY7D2mHjznN9FclUdUI+4xMdgR9K4kodoC+gf7s5LUs7b+JnOZH5u7sy7OIUb0/ADwtSfKUWpmoKJ7t49v59pqxJd4D5v8Srxz/mNo4KefAbZj/lEvKHGQ1PqtME2076SxAk0fhWZnHBDSRCALwVFWGfr3bOtpQbDOlk3MCL436fkJNHSRnmOE6sSH9E5+lqpv1SMyuMXd6s0kPRAIW8m5PQu9PuYJgbZZ0JTK7FNsir7Z1UqOIbw9cA== Received: from PH7P221CA0012.NAMP221.PROD.OUTLOOK.COM (2603:10b6:510:32a::29) by MW6PR12MB7070.namprd12.prod.outlook.com (2603:10b6:303:238::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.245.13; Wed, 29 Jul 2026 05:26:38 +0000 Received: from CY4PEPF0000FCC4.namprd03.prod.outlook.com (2603:10b6:510:32a:cafe::29) by PH7P221CA0012.outlook.office365.com (2603:10b6:510:32a::29) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.21.270.13 via Frontend Transport; Wed, 29 Jul 2026 05:26:38 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 216.228.117.161) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 216.228.117.161 as permitted sender) receiver=protection.outlook.com; client-ip=216.228.117.161; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (216.228.117.161) by CY4PEPF0000FCC4.mail.protection.outlook.com (10.167.242.106) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.270.5 via Frontend Transport; Wed, 29 Jul 2026 05:26:38 +0000 Received: from rnnvmail201.nvidia.com (10.129.68.8) by mail.nvidia.com (10.129.200.67) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.20; Tue, 28 Jul 2026 22:26:24 -0700 Received: from rnnvmail203.nvidia.com (10.129.68.9) by rnnvmail201.nvidia.com (10.129.68.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.20; Tue, 28 Jul 2026 22:26:23 -0700 Received: from nvidia.com (10.127.8.11) by mail.nvidia.com (10.129.68.9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.20 via Frontend Transport; Tue, 28 Jul 2026 22:26:19 -0700 Date: Tue, 28 Jul 2026 22:26:19 -0700 From: Nicolin Chen To: Pranjal Shrivastava CC: , , , , , , , , , , , , , , , , Subject: Re: [PATCH v2 03/11] iommu/arm-smmu-v3: Add arm_smmu_drain_queue_for_iopf() helper Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-NV-OnPremToCloud: ExternallySecured X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY4PEPF0000FCC4:EE_|MW6PR12MB7070:EE_ X-MS-Office365-Filtering-Correlation-Id: 78670cca-19fb-43b9-a4a9-08deed31f6d1 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|7416014|1800799024|36860700016|376014|23010399003|56012099006|4143699003|11063799006|10067099003|18002099003|22082099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:216.228.117.161;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc6edge2.nvidia.com;CAT:NONE;SFS:(13230040)(82310400026)(7416014)(1800799024)(36860700016)(376014)(23010399003)(56012099006)(4143699003)(11063799006)(10067099003)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: ZO6fCeNsgC62aKdR1QePNKIGzURPmv1/9hVv0b+x/sC3AVVUGxW/SBxE1ISi5R4xb0iwaKsuLh5aOdaCqn5tFejOvsVEyPTbAALrOhr6IYo3FlkZmWrPN20Sygi3mvMfZZDHA8I7oxucCaRntypOXu9zeyMKFDOHWQ1BGqcxoHZ2rY1Ck940rmQQ8NUh5XQEkIP+pjFqyi03t5iQj8CKbLVLNZkcMZ0YBybUSvXlDuuRxYa3EC4FO8XKpWRmbVHZVR2/liTogDinn16cujJDSCZjWrTrg4Mai1VSVzpj8dt8vchh+/f9PeQrVy8zKpvQs+ZLnNYk8rdOemaHcds8ovtqhkZPk0LEVNqM3Y8LZRu5d6uP6gjq6yiB6+9lBcOL2EPEo9bq92ln/siZ+U2vxbDZv/MO9116xHHH5Q6JE0ulr5DeD/1a5zmPsVMVwIsE X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Jul 2026 05:26:38.2225 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 78670cca-19fb-43b9-a4a9-08deed31f6d1 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.161];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000FCC4.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW6PR12MB7070 On Wed, Jul 29, 2026 at 05:15:43AM +0000, Pranjal Shrivastava wrote: > For PRIQ/EVTQ, my only worry was the HW producing more events, > say Device A is detached (we call drain from attach_release) but Device B > (still attached) starts an agressive DMA with multiple PRI requests/evts. > > Maybe we should go back to snapshot based polling for that? If you look closely, "pending" is the snapshot, regardless of the growing prod. * With @until_empty == false (for EVTQ/PRIQ), exit once "drained" reaches its * target: "pending" (i.e. prod0 - cons0, frozen at the entry time): * * cons0 cons prod0 (prod) * |<---- drained ---->| | | * ---+###################+=====================+=============+---> * |<--------------- pending --------------->| Nicolin