perf counters context: remove cpu hotplug compatibility code

diff --git a/lttng-context-perf-counters.c b/lttng-context-perf-counters.c
index dff5329544e68e908e3d7ffeebf2939e550fb24a..b44e69263d6b9a3c4fade7330235e8e4a0fb6f61 100644 (file)
--- a/lttng-context-perf-counters.c
+++ b/lttng-context-perf-counters.c
@@ -70,7 +70,6 @@ void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
 {
        struct perf_event **events = field->u.perf_counter->e;
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
        {
                int ret;
 
@@ -81,27 +80,12 @@ void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
                        &field->u.perf_counter->cpuhp_prepare.node);
                WARN_ON(ret);
        }
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-       {
-               int cpu;
-
-               get_online_cpus();
-               for_each_online_cpu(cpu)
-                       perf_event_release_kernel(events[cpu]);
-               put_online_cpus();
-#ifdef CONFIG_HOTPLUG_CPU
-               unregister_cpu_notifier(&field->u.perf_counter->nb);
-#endif
-       }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
        kfree(field->event_field.name);
        kfree(field->u.perf_counter->attr);
        kvfree(events);
        kfree(field->u.perf_counter);
 }
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
-
 int lttng_cpuhp_perf_counter_online(unsigned int cpu,
                struct lttng_cpuhp_node *node)
 {
@@ -141,67 +125,6 @@ int lttng_cpuhp_perf_counter_dead(unsigned int cpu,
        return 0;
 }
 
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-/**
- *     lttng_perf_counter_hp_callback - CPU hotplug callback
- *     @nb: notifier block
- *     @action: hotplug action to take
- *     @hcpu: CPU number
- *
- *     Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
- *
- * We can setup perf counters when the cpu is online (up prepare seems to be too
- * soon).
- */
-static
-int lttng_perf_counter_cpu_hp_callback(struct notifier_block *nb,
-                                                unsigned long action,
-                                                void *hcpu)
-{
-       unsigned int cpu = (unsigned long) hcpu;
-       struct lttng_perf_counter_field *perf_field =
-               container_of(nb, struct lttng_perf_counter_field, nb);
-       struct perf_event **events = perf_field->e;
-       struct perf_event_attr *attr = perf_field->attr;
-       struct perf_event *pevent;
-
-       if (!perf_field->hp_enable)
-               return NOTIFY_OK;
-
-       switch (action) {
-       case CPU_ONLINE:
-       case CPU_ONLINE_FROZEN:
-               pevent = perf_event_create_kernel_counter(attr,
-                               cpu, NULL, overflow_callback, NULL);
-               if (!pevent || IS_ERR(pevent))
-                       return NOTIFY_BAD;
-               if (pevent->state == PERF_EVENT_STATE_ERROR) {
-                       perf_event_release_kernel(pevent);
-                       return NOTIFY_BAD;
-               }
-               barrier();      /* Create perf counter before setting event */
-               events[cpu] = pevent;
-               break;
-       case CPU_UP_CANCELED:
-       case CPU_UP_CANCELED_FROZEN:
-       case CPU_DEAD:
-       case CPU_DEAD_FROZEN:
-               pevent = events[cpu];
-               events[cpu] = NULL;
-               barrier();      /* NULLify event before perf counter teardown */
-               perf_event_release_kernel(pevent);
-               break;
-       }
-       return NOTIFY_OK;
-}
-
-#endif
-
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
 int lttng_add_perf_counter_to_ctx(uint32_t type,
                                  uint64_t config,
                                  const char *name,
@@ -254,8 +177,6 @@ int lttng_add_perf_counter_to_ctx(uint32_t type,
                goto find_error;
        }
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
-
        perf_field->cpuhp_prepare.component = LTTNG_CONTEXT_PERF_COUNTERS;
        ret = cpuhp_state_add_instance(lttng_hp_prepare,
                &perf_field->cpuhp_prepare.node);
@@ -268,34 +189,6 @@ int lttng_add_perf_counter_to_ctx(uint32_t type,
        if (ret)
                goto cpuhp_online_error;
 
-#else  /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-       {
-               int cpu;
-
-#ifdef CONFIG_HOTPLUG_CPU
-               perf_field->nb.notifier_call =
-                       lttng_perf_counter_cpu_hp_callback;
-               perf_field->nb.priority = 0;
-               register_cpu_notifier(&perf_field->nb);
-#endif
-               get_online_cpus();
-               for_each_online_cpu(cpu) {
-                       events[cpu] = perf_event_create_kernel_counter(attr,
-                                               cpu, NULL, overflow_callback, NULL);
-                       if (!events[cpu] || IS_ERR(events[cpu])) {
-                               ret = -EINVAL;
-                               goto counter_error;
-                       }
-                       if (events[cpu]->state == PERF_EVENT_STATE_ERROR) {
-                               ret = -EBUSY;
-                               goto counter_busy;
-                       }
-               }
-               put_online_cpus();
-               perf_field->hp_enable = 1;
-       }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
        field->destroy = lttng_destroy_perf_counter_field;
 
        field->event_field.name = name_alloc;
@@ -313,7 +206,6 @@ int lttng_add_perf_counter_to_ctx(uint32_t type,
 
        return 0;
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
 cpuhp_online_error:
        {
                int remove_ret;
@@ -323,22 +215,6 @@ cpuhp_online_error:
                WARN_ON(remove_ret);
        }
 cpuhp_prepare_error:
-#else  /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-counter_busy:
-counter_error:
-       {
-               int cpu;
-
-               for_each_online_cpu(cpu) {
-                       if (events[cpu] && !IS_ERR(events[cpu]))
-                               perf_event_release_kernel(events[cpu]);
-               }
-               put_online_cpus();
-#ifdef CONFIG_HOTPLUG_CPU
-               unregister_cpu_notifier(&perf_field->nb);
-#endif
-       }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
 find_error:
        lttng_remove_context_field(ctx, field);
 append_context_error: