X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fconsumer%2Fconsumer.c;h=fbbe8ea8fe8907b71db0a59cc5737faad192b04a;hp=5a39a0cc7e22822154ed2c6da334df0c1693355f;hb=a9dde553270b4e8f3f280706e3f19f8f3ac41e1b;hpb=5416a504a1ff9f2444e594084836dc8b59739526

diff --git a/src/common/consumer/consumer.c b/src/common/consumer/consumer.c
index 5a39a0cc7..fbbe8ea8f 100644
--- a/src/common/consumer/consumer.c
+++ b/src/common/consumer/consumer.c
@@ -4025,14 +4025,23 @@ int lttng_consumer_rotate_channel(struct lttng_consumer_channel *channel,
 		}
 
 		/*
-		 * Active flush; has no effect if the production position
-		 * is at a packet boundary.
+		 * Do not flush an empty packet when rotating from a NULL trace
+		 * chunk. The stream has no means to output data, and the prior
+		 * rotation which rotated to NULL performed that side-effect already.
 		 */
-		ret = consumer_flush_buffer(stream, 1);
-		if (ret < 0) {
-			ERR("Failed to flush stream %" PRIu64 " during channel rotation",
-					stream->key);
-			goto end_unlock_stream;
+		if (stream->trace_chunk) {
+			/*
+			 * For metadata stream, do an active flush, which does not
+			 * produce empty packets. For data streams, empty-flush;
+			 * ensures we have at least one packet in each stream per trace
+			 * chunk, even if no data was produced.
+			 */
+			ret = consumer_flush_buffer(stream, stream->metadata_flag ? 1 : 0);
+			if (ret < 0) {
+				ERR("Failed to flush stream %" PRIu64 " during channel rotation",
+						stream->key);
+				goto end_unlock_stream;
+			}
 		}
 
 		ret = lttng_consumer_take_snapshot(stream);