[PATCH v13 14/32] x86,fs/resctrl: Add and initialize rdt_resource for package scope monitor

Tony Luck
2025-10-29T16:21:36Z

Add a new PERF_PKG resource and introduce package level scope for
monitoring telemetry events so that CPU hot plug notifiers can build
domains at the package granularity.

Use the physical package ID available via topology_physical_package_id()
to identify the monitoring domains with package level scope. This enables
user space to use:
/sys/devices/system/cpu/cpuX/topology/physical_package_id
to identify the monitoring domain a CPU is associated with.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
include/linux/resctrl.h | 2 ++
fs/resctrl/internal.h | 2 ++
arch/x86/kernel/cpu/resctrl/core.c | 10 ++++++++++
fs/resctrl/rdtgroup.c | 2 ++
4 files changed, 16 insertions(+)

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 1634db6176c3..9fe6205743b7 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -53,6 +53,7 @@ enum resctrl_res_level {
RDT_RESOURCE_L2,
RDT_RESOURCE_MBA,
RDT_RESOURCE_SMBA,
+ RDT_RESOURCE_PERF_PKG,

/* Must be the last */
RDT_NUM_RESOURCES,
@@ -267,6 +268,7 @@ enum resctrl_scope {
RESCTRL_L2_CACHE = 2,
RESCTRL_L3_CACHE = 3,
RESCTRL_L3_NODE,
+ RESCTRL_PACKAGE,
};

/**
diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h
index f5189b6771a0..96d97f4ff957 100644
--- a/fs/resctrl/internal.h
+++ b/fs/resctrl/internal.h
@@ -255,6 +255,8 @@ struct rdtgroup {

#define RFTYPE_ASSIGN_CONFIG BIT(11)

+#define RFTYPE_RES_PERF_PKG BIT(11)
+
#define RFTYPE_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL)

#define RFTYPE_MON_INFO (RFTYPE_INFO | RFTYPE_MON)
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 980a4d9e5267..af555dadf024 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -100,6 +100,14 @@ struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] = {
.schema_fmt = RESCTRL_SCHEMA_RANGE,
},
},
+ [RDT_RESOURCE_PERF_PKG] =
+ {
+ .r_resctrl = {
+ .name = "PERF_PKG",
+ .mon_scope = RESCTRL_PACKAGE,
+ .mon_domains = mon_domain_init(RDT_RESOURCE_PERF_PKG),
+ },
+ },
};

u32 resctrl_arch_system_num_rmid_idx(void)
@@ -435,6 +443,8 @@ static int get_domain_id_from_scope(int cpu, enum resctrl_scope scope)
return get_cpu_cacheinfo_id(cpu, scope);
case RESCTRL_L3_NODE:
return cpu_to_node(cpu);
+ case RESCTRL_PACKAGE:
+ return topology_physical_package_id(cpu);
default:
break;
}
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index a4d4d4080e87..26f0d1f93da2 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -2330,6 +2330,8 @@ static unsigned long fflags_from_resource(struct rdt_resource *r)
case RDT_RESOURCE_MBA:
case RDT_RESOURCE_SMBA:
return RFTYPE_RES_MB;
+ case RDT_RESOURCE_PERF_PKG:
+ return RFTYPE_RES_PERF_PKG;
}

return WARN_ON_ONCE(1);
--
2.51.0