+enum cpuhp_state lttng_hp_prepare;
+enum cpuhp_state lttng_hp_online;
+
+static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
+{
+ struct lttng_cpuhp_node *lttng_node;
+
+ lttng_node = container_of(node, struct lttng_cpuhp_node, node);
+ switch (lttng_node->component) {
+ case LTTNG_RING_BUFFER_FRONTEND:
+ return 0;
+ case LTTNG_RING_BUFFER_BACKEND:
+ return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
+ case LTTNG_RING_BUFFER_ITER:
+ return 0;
+ case LTTNG_CONTEXT_PERF_COUNTERS:
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
+{
+ struct lttng_cpuhp_node *lttng_node;
+
+ lttng_node = container_of(node, struct lttng_cpuhp_node, node);
+ switch (lttng_node->component) {
+ case LTTNG_RING_BUFFER_FRONTEND:
+ return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
+ case LTTNG_RING_BUFFER_BACKEND:
+ return 0;
+ case LTTNG_RING_BUFFER_ITER:
+ return 0;
+ case LTTNG_CONTEXT_PERF_COUNTERS:
+ return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
+{
+ struct lttng_cpuhp_node *lttng_node;
+
+ lttng_node = container_of(node, struct lttng_cpuhp_node, node);
+ switch (lttng_node->component) {
+ case LTTNG_RING_BUFFER_FRONTEND:
+ return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
+ case LTTNG_RING_BUFFER_BACKEND:
+ return 0;
+ case LTTNG_RING_BUFFER_ITER:
+ return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
+ case LTTNG_CONTEXT_PERF_COUNTERS:
+ return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
+{
+ struct lttng_cpuhp_node *lttng_node;
+
+ lttng_node = container_of(node, struct lttng_cpuhp_node, node);
+ switch (lttng_node->component) {
+ case LTTNG_RING_BUFFER_FRONTEND:
+ return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
+ case LTTNG_RING_BUFFER_BACKEND:
+ return 0;
+ case LTTNG_RING_BUFFER_ITER:
+ return 0;
+ case LTTNG_CONTEXT_PERF_COUNTERS:
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int __init lttng_init_cpu_hotplug(void)