From 4bbfc90122e974ccbd9aa80c964413052b9519f3 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Thu, 8 Jan 2026 09:42:27 -0800 Subject: [PATCH] x86/resctrl: Enable RDT_RESOURCE_PERF_PKG Since telemetry events are enumerated on resctrl mount the RDT_RESOURCE_PERF_PKG resource is not considered "monitoring capable" during early resctrl initialization. This means that the domain list for RDT_RESOURCE_PERF_PKG is not built when the CPU hotplug notifiers are registered and run for the first time right after resctrl initialization. Mark the RDT_RESOURCE_PERF_PKG as "monitoring capable" upon successful telemetry event enumeration to ensure future CPU hotplug events include this resource and initialize its domain list for CPUs that are already online. Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com --- arch/x86/kernel/cpu/resctrl/core.c | 16 ++++++++++++++++ arch/x86/kernel/cpu/resctrl/intel_aet.c | 6 ++++++ 2 files changed, 22 insertions(+) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 0da44cad28fdb..9fcc06e9e72e6 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -766,8 +766,24 @@ static int resctrl_arch_offline_cpu(unsigned int cpu) void resctrl_arch_pre_mount(void) { + struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_PERF_PKG].r_resctrl; + int cpu; + if (!intel_aet_get_events()) return; + + /* + * Late discovery of telemetry events means the domains for the + * resource were not built. Do that now. + */ + cpus_read_lock(); + mutex_lock(&domain_list_lock); + r->mon_capable = true; + rdt_mon_capable = true; + for_each_online_cpu(cpu) + domain_add_cpu_mon(cpu, r); + mutex_unlock(&domain_list_lock); + cpus_read_unlock(); } enum { diff --git a/arch/x86/kernel/cpu/resctrl/intel_aet.c b/arch/x86/kernel/cpu/resctrl/intel_aet.c index aba9971350031..89b8b619d5d53 100644 --- a/arch/x86/kernel/cpu/resctrl/intel_aet.c +++ b/arch/x86/kernel/cpu/resctrl/intel_aet.c @@ -270,6 +270,12 @@ static bool enable_events(struct event_group *e, struct pmt_feature_group *p) else r->mon.num_rmid = e->num_rmid; + if (skipped_events) + pr_info("%s %s:0x%x monitoring detected (skipped %d events)\n", r->name, + e->pfname, e->guid, skipped_events); + else + pr_info("%s %s:0x%x monitoring detected\n", r->name, e->pfname, e->guid); + return true; } -- 2.47.3