ring buffer iterator: remove cpu hotplug compatibility code

diff --git a/lib/ringbuffer/ring_buffer_iterator.c b/lib/ringbuffer/ring_buffer_iterator.c
index df09aabc1afc49fb936e1ece33948dbcd008bc02..e74214ee4b21ea4eab5188eeaaefb510d614855d 100644 (file)
--- a/lib/ringbuffer/ring_buffer_iterator.c
+++ b/lib/ringbuffer/ring_buffer_iterator.c
@@ -335,8 +335,6 @@ void lib_ring_buffer_iterator_init(struct channel *chan, struct lib_ring_buffer
                list_add(&buf->iter.empty_node, &chan->iter.empty_head);
 }
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
-
 int lttng_cpuhp_rb_iter_online(unsigned int cpu,
                struct lttng_cpuhp_node *node)
 {
@@ -352,40 +350,6 @@ int lttng_cpuhp_rb_iter_online(unsigned int cpu,
 }
 EXPORT_SYMBOL_GPL(lttng_cpuhp_rb_iter_online);
 
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
-#ifdef CONFIG_HOTPLUG_CPU
-static
-int channel_iterator_cpu_hotplug(struct notifier_block *nb,
-                                          unsigned long action,
-                                          void *hcpu)
-{
-       unsigned int cpu = (unsigned long)hcpu;
-       struct channel *chan = container_of(nb, struct channel,
-                                           hp_iter_notifier);
-       struct lib_ring_buffer *buf = per_cpu_ptr(chan->backend.buf, cpu);
-       const struct lib_ring_buffer_config *config = &chan->backend.config;
-
-       if (!chan->hp_iter_enable)
-               return NOTIFY_DONE;
-
-       CHAN_WARN_ON(chan, config->alloc == RING_BUFFER_ALLOC_GLOBAL);
-
-       switch (action) {
-       case CPU_DOWN_FAILED:
-       case CPU_DOWN_FAILED_FROZEN:
-       case CPU_ONLINE:
-       case CPU_ONLINE_FROZEN:
-               lib_ring_buffer_iterator_init(chan, buf);
-               return NOTIFY_OK;
-       default:
-               return NOTIFY_DONE;
-       }
-}
-#endif
-
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
 int channel_iterator_init(struct channel *chan)
 {
        const struct lib_ring_buffer_config *config = &chan->backend.config;
@@ -401,42 +365,11 @@ int channel_iterator_init(struct channel *chan)
                if (ret)
                        return ret;
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
                chan->cpuhp_iter_online.component = LTTNG_RING_BUFFER_ITER;
                ret = cpuhp_state_add_instance(lttng_rb_hp_online,
                        &chan->cpuhp_iter_online.node);
                if (ret)
                        return ret;
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-               {
-                       int cpu;
-
-                       /*
-                        * In case of non-hotplug cpu, if the ring-buffer is allocated
-                        * in early initcall, it will not be notified of secondary cpus.
-                        * In that off case, we need to allocate for all possible cpus.
-                        */
-#ifdef CONFIG_HOTPLUG_CPU
-                       chan->hp_iter_notifier.notifier_call =
-                               channel_iterator_cpu_hotplug;
-                       chan->hp_iter_notifier.priority = 10;
-                       register_cpu_notifier(&chan->hp_iter_notifier);
-
-                       get_online_cpus();
-                       for_each_online_cpu(cpu) {
-                               buf = per_cpu_ptr(chan->backend.buf, cpu);
-                               lib_ring_buffer_iterator_init(chan, buf);
-                       }
-                       chan->hp_iter_enable = 1;
-                       put_online_cpus();
-#else
-                       for_each_possible_cpu(cpu) {
-                               buf = per_cpu_ptr(chan->backend.buf, cpu);
-                               lib_ring_buffer_iterator_init(chan, buf);
-                       }
-#endif
-               }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
        } else {
                buf = channel_get_ring_buffer(config, chan, 0);
                lib_ring_buffer_iterator_init(chan, buf);
@@ -449,7 +382,6 @@ void channel_iterator_unregister_notifiers(struct channel *chan)
        const struct lib_ring_buffer_config *config = &chan->backend.config;
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
                {
                        int ret;
 
@@ -457,10 +389,6 @@ void channel_iterator_unregister_notifiers(struct channel *chan)
                                &chan->cpuhp_iter_online.node);
                        WARN_ON(ret);
                }
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-               chan->hp_iter_enable = 0;
-               unregister_cpu_notifier(&chan->hp_iter_notifier);
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
        }
 }