Version 2.4.4

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

diff --git a/wrapper/poll.h b/wrapper/poll.h
index 416ce5740da7a6e15b88401e209c49dc54860310..c26610ea990ca57c1dd97cf5f89064aca771b97c 100644 (file)
--- a/wrapper/poll.h
+++ b/wrapper/poll.h
@@ -1,20 +1,33 @@
+#ifndef _LTTNG_WRAPPER_POLL_H
+#define _LTTNG_WRAPPER_POLL_H
+
 /*
  * wrapper/poll.h
  *
- * Copyright (C) 2010-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
  *
- * Dual LGPL v2.1/GPL v2 license.
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#ifndef CONFIG_LIB_RING_BUFFER
 #include <linux/poll.h>
 
-#warning "poll_wait_set_exclusive() is defined as no-op. Will increase LTTng overhead. Please consider using the LTTng kernel tree for better results."
-
 /*
- * 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 */