Drop support for kernels < 3.0 from jbd2 instrumentation

[lttng-modules.git] / wrapper / poll.h

diff --git a/wrapper/poll.h b/wrapper/poll.h
index 71ebce94bb50218a729aaa8d4391bd1f48789d3c..dde5c55b9562856b074a8daf1c415705e02b3a9c 100644 (file)
--- a/wrapper/poll.h
+++ b/wrapper/poll.h
@@ -1,12 +1,20 @@
-#ifndef CONFIG_LIB_RING_BUFFER
-#include <linux/poll.h>
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
+ * wrapper/poll.h
+ *
+ * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
 
-#warning "poll_wait_set_exclusive() is defined as no-op. Will increase LTTng overhead. Please consider using the LTTng kernel tree for better results."
+#ifndef _LTTNG_WRAPPER_POLL_H
+#define _LTTNG_WRAPPER_POLL_H
+
+#include <linux/poll.h>
 
 /*
- * Will cause higher overhead when signalling all possible reader threads when a
- * buffer is ready to be consumed.
+ * Note: poll_wait_set_exclusive() is defined as no-op. Thundering herd
+ * effect can be noticed with large number of consumer threads.
  */
+
 #define poll_wait_set_exclusive(poll_table)
 
-#endif
+#endif /* _LTTNG_WRAPPER_POLL_H */