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Mon, 23 Mar 2026 17:11:48 +0000 Date: Mon, 23 Mar 2026 10:11:42 -0700 From: Matthew Brost To: Boris Brezillon CC: Daniel Almeida , , , "Tvrtko Ursulin" , Rodrigo Vivi , Thomas =?iso-8859-1?Q?Hellstr=F6m?= , Christian =?iso-8859-1?Q?K=F6nig?= , "Danilo Krummrich" , David Airlie , "Maarten Lankhorst" , Maxime Ripard , Philipp Stanner , Simona Vetter , Sumit Semwal , Thomas Zimmermann , , Sami Tolvanen , Jeffrey Vander Stoep , "Alice Ryhl" , Daniel Stone , "Alexandre Courbot" , John Hubbard , , , Eliot Courtney , Joel Fernandes , rust-for-linux Subject: Re: [RFC PATCH 02/12] drm/dep: Add DRM dependency queue layer Message-ID: References: <20260316043255.226352-3-matthew.brost@intel.com> <7A8108C7-7CF0-4EA4-95ED-8003502DC35A@collabora.com> <20260317214320.74e6c130@fedora> <20260319105729.2c20116d@fedora> <20260323110613.6b153163@fedora> Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260323110613.6b153163@fedora> X-ClientProxiedBy: MW4PR04CA0095.namprd04.prod.outlook.com (2603:10b6:303:83::10) To BL3PR11MB6508.namprd11.prod.outlook.com (2603:10b6:208:38f::5) Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL3PR11MB6508:EE_|BY1PR11MB8053:EE_ X-MS-Office365-Filtering-Correlation-Id: 97b682d2-46da-4148-5c66-08de88ff4455 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|7416014|376014|366016|56012099003|18002099003|22082099003; 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I'd really > > > > prefer something like: > > > > > > > > > > You are completely missing the point here. > > > > > > > Let me rephrase this — I realize this may come across as rude, which is > > not my intent. > > No offense taken ;-). > > > I believe there is simply a disconnect in understanding > > the constraints. > > > > In my example below, the job release completes within bounded time > > constraints, which makes it suitable for direct release in IRQ context, > > bypassing the need for a work item that would otherwise incur a costly > > CPU context switch. > > In the other thread, I've explained in more details why I think > deferred cleanup of jobs is not as bad as you make it sound (context > switch amortized by the fact it's already there for queue progress > checking). But let's assume it is, I'd prefer a model where we say > "ops->job_release() has to be IRQ-safe" and have implementations defer > their cleanup if they have to, than this mixed approach with a flag. Of > course, I'd still like to have numbers proving that this job cleanup > deferral actually makes a difference in practice :P. Yes, I replied there will either drop this or have solid numbers showing yes, the CPU utlization shows this is worth while. Matt