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X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 01 Sep 2025 03:57:51.4568 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: f569f11f-5118-4062-a4e9-08dde90bb90c 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=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: MN1PEPF0000ECD5.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB6283 (Trimming the cc to kernel/sched/ folks) On 8/26/2025 2:57 PM, Shrikanth Hegde wrote: > > > On 8/26/25 9:43 AM, K Prateek Nayak wrote: >> PowerPC enables the MC scheduling domain by default on systems with >> coregroup support without having a SCHED_MC config in Kconfig. >> >> The scheduler uses CONFIG_SCHED_MC to introduce the MC domain in the >> default topology (core) and to optimize the default CPU selection >> routine (sched-ext). > > Curious to know if sched_ext usage. i see below code. > > if (static_branch_maybe(CONFIG_SCHED_MC, &scx_selcpu_topo_llc)) > > scx_selcpu_topo_llc = true if there is sd_llc. One can have llc domain without MC domain. > I am wondering whats the reason behind the clubbing. Seems to be an artifact carried forward since commit dfa4ed29b18c ("sched_ext: Introduce LLC awareness to the default idle selection policy") The commit 860a45219bce ("sched_ext: Introduce NUMA awareness to the default idle selection policy") continued to build on top of that except that it was fine to put the NUMA bits behind CONFIG_NUMA check since topology.c only adds SD_NUMA under those circumstances but sd_llc is just the highest SD_SHARE_LLC domain and shouldn't really depend on CONFIG_SCHED_MC. The ext part already has a check for llc_numa_mismatch() to only enable "scx_selcpu_topo_numa" when llc and NUMA boundaries don't overlap so I think that dependency on CONFIG_SCHED_MC can be safely removed. -- Thanks and Regards, Prateek