Import fix from LTSI: 3.4+ RT kernels use CONFIG_PREEMPT_RT_FULL

[lttng-modules.git] / lttng-events.c

diff --git a/lttng-events.c b/lttng-events.c
index 879097b4a8c7af056c0f0ec57dbef4d9376e7c57..0faff8498df3d61eb972415a4b1c1336ccce20a4 100644 (file)
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -31,6 +31,7 @@
 #include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
 #include "wrapper/random.h"
 #include "wrapper/tracepoint.h"
+#include "lttng-kernel-version.h"
 #include "lttng-events.h"
 #include "lttng-tracer.h"
 #include "lttng-abi-old.h"
@@ -60,9 +61,15 @@ void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
 void synchronize_trace(void)
 {
        synchronize_sched();
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
+#ifdef CONFIG_PREEMPT_RT_FULL
+       synchronize_rcu();
+#endif
+#else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
 #ifdef CONFIG_PREEMPT_RT
        synchronize_rcu();
 #endif
+#endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
 }
 
 struct lttng_session *lttng_session_create(void)
@@ -553,6 +560,8 @@ void _lttng_event_destroy(struct lttng_event *event)
  * sessions_mutex), so we can do racy operations such as looking for
  * remaining space left in packet and write, since mutual exclusion
  * protects us from concurrent writes.
+ * Returns the number of bytes written in the channel, 0 if no data
+ * was written and a negative value on error.
  */
 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
                struct channel *chan)