X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.c;h=42d471d1a9a040b10e6ee48b56d66f34544f8091;hp=2ea5fa114223f101362e4d780d106b25b3812238;hb=c13082a921ed95e1039d1e28da35941930b15fb6;hpb=19356f3ab163d5ee161900db49247996f49dfc35

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 2ea5fa114..42d471d1a 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -141,6 +141,8 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
 	}
 
 	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();
 
@@ -227,6 +229,7 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
 		while (consumed_pos < produced_pos) {
 			ssize_t read_len;
 			unsigned long len, padded_len;
+			int lost_packet = 0;
 
 			health_code_update();
 
@@ -241,6 +244,15 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
 				}
 				DBG("Kernel 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;
 			}
 
@@ -284,6 +296,16 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
 				goto end_unlock;
 			}
 			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;
 		}
 
 		if (relayd_id == (uint64_t) -1ULL) {