2 files changed, 13 insertions, 6 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 4d6ce5d612da..26604188aa49 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -30,6 +30,7 @@
 #include <asm/stacktrace.h>
 #include <asm/nmi.h>
 #include <asm/compat.h>
+#include <asm/smp.h>
 
 #if 0
 #undef wrmsrl
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 6e9b6763ff48..8fc2b2cee1da 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1205,6 +1205,9 @@ static int intel_pmu_cpu_prepare(int cpu)
 {
         struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
 
+        if (!cpu_has_ht_siblings())
+                return NOTIFY_OK;
+
         cpuc->per_core = kzalloc_node(sizeof(struct intel_percore),
                                       GFP_KERNEL, cpu_to_node(cpu));
         if (!cpuc->per_core)
@@ -1221,6 +1224,15 @@ static void intel_pmu_cpu_starting(int cpu)
         int core_id = topology_core_id(cpu);
         int i;
 
+        init_debug_store_on_cpu(cpu);
+        /*
+         * Deal with CPUs that don't clear their LBRs on power-up.
+         */
+        intel_pmu_lbr_reset();
+
+        if (!cpu_has_ht_siblings())
+                return;
+
         for_each_cpu(i, topology_thread_cpumask(cpu)) {
                 struct intel_percore *pc = per_cpu(cpu_hw_events, i).per_core;
 
@@ -1233,12 +1245,6 @@ static void intel_pmu_cpu_starting(int cpu)
 
         cpuc->per_core->core_id = core_id;
         cpuc->per_core->refcnt++;
-
-        init_debug_store_on_cpu(cpu);
-        /*
-         * Deal with CPUs that don't clear their LBRs on power-up.
-         */
-        intel_pmu_lbr_reset();
 }
 
 static void intel_pmu_cpu_dying(int cpu)