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McKenney" , Metin Kaya , Xuewen Yan , Thomas Gleixner , Daniel Lezcano , Suleiman Souhlal , kuyo chang , hupu , , Mike Galbraith References: <20260526111609.433880331@infradead.org> <20260526113322.120970670@infradead.org> Content-Language: en-US From: K Prateek Nayak In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY4PEPF0000EDD5:EE_|MN0PR12MB5931:EE_ X-MS-Office365-Filtering-Correlation-Id: e3aafea9-792b-4c59-453e-08debd5bb157 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|82310400026|376014|36860700016|1800799024|56012099006|4143699003|11063799006|22082099003|18002099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb07.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(7416014)(82310400026)(376014)(36860700016)(1800799024)(56012099006)(4143699003)(11063799006)(22082099003)(18002099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: Aw4yy2iTMeLWJsP//YLtloLObHLhaSJ+ABF+/meKih+ycy+YiFT+e8H4ivi6YeG+ILE/pUOhsnEnJNBXD6d/WKeiO7vKabykyxvYm2e2EK5ZbRmgXV0QYxgi003CuEf6eNM3CWZEP0KVu3hxwTtFdWdKJjsA0mSC09clJdr/xHEHbIcAZ+exFFKu+44C/kmcpPrRA9NtJ+bF/RXIuVPtIlTE+zfdy1YMfVhu0TdRj45CIK0ra1M0TMUSqA/84BfeeJUuWJvT5LKweWcDOuzoDHUZpyMpuTKKqLi/Uaq299kaFZ5i2hP71zUMVWJLN+X/AmjgMRAHxM6tQ72lY5pm4Puf6Ernr+37F7a2QQw5t11bw9qENWLpqZ6OF3AQk6GQIK64EjVGExV7ssOnounGm4NZpYVg4Vn7AQKj3QNYgCBnMvMtbMY7cRk1WptjjDUE X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 May 2026 08:24:24.7663 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: e3aafea9-792b-4c59-453e-08debd5bb157 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=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000EDD5.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN0PR12MB5931 Hello John, On 5/29/2026 12:44 PM, John Stultz wrote: > You see these things so quickly! :) Beat me sending out my own > analysis (which is maybe a slightly different case, but still). That was an interesting case too! My brain defaults to one lock and two CPUs but your brain goes a few step (and a few locks, CPUs) further ;-) >> Part of that belongs in commit e2ff8b7bde07 ("sched/proxy: Only return >> migrate when needed") and the first hunk of 83f9b04ef50c ("sched/proxy: >> Switch proxy to use p->is_blocked") in proxy_needs_return() should be >> dropped. > > Very nice, yes this does help when the "Only return migrate when > needed" is added! > > So I've included this and reworked the order of Peter's doodles slightly to be: > sched/proxy: Optimize try_to_wake_up() > sched: Be more strict about p->is_blocked > sched/proxy: Only return migrate when needed > FOLD: k prateek's fixup > sched/proxy: Switch proxy to use p->is_blocked > sched/proxy: Remove PROXY_WAKING > sched/proxy: Remove superfluous clear_task_blocked_in() > sched: Simplify ttwu_runnable() Ack! That should cover all bases. > > Which seems to be working at each step. Though I've only lightly > tested and I didn't trip this initially with the series, so more > testing will be needed tommorow. Meanwhile, I'll rearrange the patches like you suggested above and run some testes too. Fingers crossed -- Thanks and Regards, Prateek