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authorTom Zanussi <tzanussi@gmail.com>2009-03-22 09:30:49 +0100
committerIngo Molnar <mingo@elte.hu>2009-03-22 18:38:25 +0100
commit2d622719f1572ef31e0616444a515eba3094d050 (patch)
treef9bffcdca6289f141fb53a38dd9f32af8c71efad /include
parenttracing: add run-time field descriptions for event filtering (diff)
downloadlinux-2d622719f1572ef31e0616444a515eba3094d050.tar.xz
linux-2d622719f1572ef31e0616444a515eba3094d050.zip
tracing: add ring_buffer_event_discard() to ring buffer
This patch overloads RINGBUF_TYPE_PADDING to provide a way to discard events from the ring buffer, for the event-filtering mechanism introduced in a subsequent patch. I did the initial version but thanks to Steven Rostedt for adding the parts that actually made it work. ;-) Signed-off-by: Tom Zanussi <tzanussi@gmail.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
-rw-r--r--include/linux/ring_buffer.h11
1 files changed, 8 insertions, 3 deletions
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 9e6052bd1a1c..e1b7b2173885 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -18,10 +18,13 @@ struct ring_buffer_event {
/**
* enum ring_buffer_type - internal ring buffer types
*
- * @RINGBUF_TYPE_PADDING: Left over page padding
- * array is ignored
- * size is variable depending on how much
+ * @RINGBUF_TYPE_PADDING: Left over page padding or discarded event
+ * If time_delta is 0:
+ * array is ignored
+ * size is variable depending on how much
* padding is needed
+ * If time_delta is non zero:
+ * everything else same as RINGBUF_TYPE_DATA
*
* @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta
* array[0] = time delta (28 .. 59)
@@ -65,6 +68,8 @@ ring_buffer_event_time_delta(struct ring_buffer_event *event)
return event->time_delta;
}
+void ring_buffer_event_discard(struct ring_buffer_event *event);
+
/*
* size is in bytes for each per CPU buffer.
*/