Add CPU hotplug notifier for ltt debugfs ABI, add pollwait exclusive wrapper

[lttng-modules.git] / lib / ringbuffer / ring_buffer_frontend.c

diff --git a/lib/ringbuffer/ring_buffer_frontend.c b/lib/ringbuffer/ring_buffer_frontend.c
index 1931414b067a4c8836b1cece70be5c5ad45ad8a7..ecc72ab84f7e3143f930e77cac0bc6ad3de16a8e 100644 (file)
--- a/lib/ringbuffer/ring_buffer_frontend.c
+++ b/lib/ringbuffer/ring_buffer_frontend.c
@@ -410,6 +410,7 @@ int __cpuinit lib_ring_buffer_cpu_hp_callback(struct notifier_block *nb,
        case CPU_DOWN_FAILED_FROZEN:
        case CPU_ONLINE:
        case CPU_ONLINE_FROZEN:
+               wake_up_interruptible(&chan->hp_wait);
                lib_ring_buffer_start_switch_timer(buf);
                lib_ring_buffer_start_read_timer(buf);
                return NOTIFY_OK;
@@ -626,6 +627,7 @@ struct channel *channel_create(const struct lib_ring_buffer_config *config,
        chan->read_timer_interval = usecs_to_jiffies(read_timer_interval);
        kref_init(&chan->ref);
        init_waitqueue_head(&chan->read_wait);
+       init_waitqueue_head(&chan->hp_wait);
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
 #if defined(CONFIG_NO_HZ) && defined(CONFIG_LIB_RING_BUFFER)
@@ -748,6 +750,8 @@ void *channel_destroy(struct channel *chan)
                ACCESS_ONCE(buf->finalized) = 1;
                wake_up_interruptible(&buf->read_wait);
        }
+       ACCESS_ONCE(chan->finalized) = 1;
+       wake_up_interruptible(&chan->hp_wait);
        wake_up_interruptible(&chan->read_wait);
        kref_put(&chan->ref, channel_release);
        priv = chan->backend.priv;