X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fust-consumer%2Fust-consumer.c;h=5b4b1496556ad298349e407a7e077413d758a121;hp=d0f7ac53ee651371ba4b59444df5a8ae6c391330;hb=c13082a921ed95e1039d1e28da35941930b15fb6;hpb=19356f3ab163d5ee161900db49247996f49dfc35

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index d0f7ac53e..5b4b14965 100644
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -1029,6 +1029,8 @@ static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
 	DBG("UST consumer snapshot channel %" PRIu64, key);
 
 	cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+		/* Are we at a position _before_ the first available packet ? */
+		bool before_first_packet = true;
 
 		health_code_update();
 
@@ -1095,6 +1097,7 @@ static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
 		while (consumed_pos < produced_pos) {
 			ssize_t read_len;
 			unsigned long len, padded_len;
+			int lost_packet = 0;
 
 			health_code_update();
 
@@ -1108,6 +1111,15 @@ static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
 				}
 				DBG("UST consumer get subbuf failed. Skipping it.");
 				consumed_pos += stream->max_sb_size;
+
+				/*
+				 * Start accounting lost packets only when we
+				 * already have extracted packets (to match the
+				 * content of the final snapshot).
+				 */
+				if (!before_first_packet) {
+					lost_packet = 1;
+				}
 				continue;
 			}
 
@@ -1143,6 +1155,16 @@ static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
 				goto error_close_stream;
 			}
 			consumed_pos += stream->max_sb_size;
+
+			/*
+			 * Only account lost packets located between
+			 * succesfully extracted packets (do not account before
+			 * and after since they are not visible in the
+			 * resulting snapshot).
+			 */
+			stream->chan->lost_packets += lost_packet;
+			lost_packet = 0;
+			before_first_packet = false;
 		}
 
 		/* Simply close the stream so we can use it on the next snapshot. */