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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: sPeB2LElnPryy+iNXo43MDsODOrKQ1mAC8fRP7rPP2Jw+nP6IaoMKg6GNcqgzza9LacNsSpPB987IJo9Cab5TH+jGcF1y12/1PgOs844tFsXkMBZt8fTWNMJnZ7y7qlJnMHB1DmYZHg+nnxvYKLJ9FHYnptgtzlKmJpVGU9HQNN4/m8Y8kHNjRtoN9cG+54mvoJGLLKJ3lktw5L5sTJoLh754Ch//LJFWD/iMMV8U/SgupJynh1CixGRwXw5ni25SSDZPzfAgVz8Q8ApTxi1CiBaXRuB9WAm5ZEcvACwWnDcBj+qXDO2E8yqi6Sh9QEh1XVmjldVeGOcGtFAUiW0Ql6mZ9G0lbxoNkHtSJniINXJf1looiYEAZbfFEzBIfHtkeMZdSxHeFPxC+GSWRk0oCWBSx9yJeXTpm26uqzXnCsVym+DMAXhdabwjuFjSbfT X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 May 2026 06:20:06.0246 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 25c982fe-5b40-4f29-2f6e-08deb0b7acf7 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: CH1PEPF0000AD7B.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR12MB8969 Hello Shrikanth, On 5/12/2026 8:51 PM, Shrikanth Hegde wrote: > Semantics > ========= > - For CONFIG_SCHED_SMT=y: > No functional change. > - For CONFIG_SCHED_SMT=n: > - cpu_smt_mask(cpu) becomes cpumask_of(cpu), effectively making it > per CPU with no siblings. > - sched_smt_present remains defined, but never becomes active: > Since cpumask_weight(cpumask_of(cpu)) == 1 > > Performance impact > ================== > - CONFIG_SCHED_SMT=y: > No change in generated code. > - CONFIG_SCHED_SMT=n: > - Small increase in text size (~0.01%) due to removal of compile-time > stubs. Most paths remain effectively dead due to static keys. > - Fast paths are protected using IS_ENABLED(CONFIG_SCHED_SMT). > > With that, cpu_smt_mask() to be used unconditionally and reduces > CONFIG_SCHED_SMT-specific code paths, improving readability and > maintainability. > > This leaves the remaining use of CONFIG_SCHED_SMT mainly for topology > handling bits. Thank you again cleaning this up! Feel free to include: Tested-by: K Prateek Nayak I also tested removing the "select SCHED_SMT" dependency for x86 after guarding SDTL_INIT(..., SMT) behind CONFIG_SCHED_SMT and the system is up fine; performance is terrible as expected :-) -- Thanks and Regards, Prateek