Counts for each Intel telemetry event are periodically sent to one or
more aggregators on each package where accumulated totals are made
available in MMIO registers.

Add a new resource for monitoring these events so that CPU hotplug
notifiers will build domains at the package granularity.

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 23e2874105e3..76c54b81e426 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,
@@ -252,6 +253,7 @@ 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 4dc678af005c..53ced959a27d 100644
--- a/fs/resctrl/internal.h
+++ b/fs/resctrl/internal.h
@@ -239,6 +239,8 @@ struct rdtgroup {
 
 #define RFTYPE_DEBUG			BIT(10)
 
+#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 03c481725fdb..a5f01cac2363 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)
@@ -433,6 +441,8 @@ 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 9dac8017a2f8..d9bb01edd582 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -2195,6 +2195,8 @@ 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);
-- 
2.49.0

Hi Tony,

On 6/26/25 9:49 AM, Tony Luck wrote:
> Counts for each Intel telemetry event are periodically sent to one or
> more aggregators on each package where accumulated totals are made
> available in MMIO registers.
> 
> Add a new resource for monitoring these events so that CPU hotplug
> notifiers will build domains at the package granularity.

Patch does a bit more than this. This can be expanded to:

	Add a new PERF_PKG resource and introduce package level scope for monitoring
	these events so that CPU hotplug 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.

(Please always feel free to improve.)

> 
> Signed-off-by: Tony Luck <tony.luck@intel.com>
> ---

Patch looks good to me.

Reinette