X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;ds=sidebyside;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.c;h=b477e6f92cefbbf41aaaca9552d7d58cf26d1387;hb=3daf8c9be3ccaa544befe6703de057c957bd0a02;hp=43a5d366348d98a1037ec4a9bef3024b0ba6a5e2;hpb=8dbd7d838dc2276e5a25057c76c2e219e1d2661b;p=lttng-tools.git

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 43a5d3663..b477e6f92 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -140,8 +140,6 @@ 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;
 		unsigned long consumed_pos, produced_pos;
 
 		health_code_update();
@@ -185,13 +183,23 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
 				ERR("sending streams sent to relayd");
 				goto end_unlock;
 			}
+			channel->streams_sent_to_relayd = true;
 		}
 
-		ret = kernctl_buffer_flush(stream->wait_fd);
+		ret = kernctl_buffer_flush_empty(stream->wait_fd);
 		if (ret < 0) {
-			ERR("Failed to flush kernel stream");
-			ret = -errno;
-			goto end_unlock;
+			/*
+			 * Doing a buffer flush which does not take into
+			 * account empty packets. This is not perfect
+			 * for stream intersection, but required as a
+			 * fall-back when "flush_empty" is not
+			 * implemented by lttng-modules.
+			 */
+			ret = kernctl_buffer_flush(stream->wait_fd);
+			if (ret < 0) {
+				ERR("Failed to flush kernel stream");
+				goto end_unlock;
+			}
 		}
 
 		ret = lttng_kconsumer_take_snapshot(stream);
@@ -229,7 +237,6 @@ 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();
 
@@ -244,15 +251,7 @@ 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;
-				}
+				stream->chan->lost_packets++;
 				continue;
 			}
 
@@ -296,16 +295,6 @@ 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) {
@@ -726,6 +715,19 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 				consumer_stream_free(new_stream);
 				goto end_nosignal;
 			}
+
+			/*
+			 * If adding an extra stream to an already
+			 * existing channel (e.g. cpu hotplug), we need
+			 * to send the "streams_sent" command to relayd.
+			 */
+			if (channel->streams_sent_to_relayd) {
+				ret = consumer_send_relayd_streams_sent(
+						new_stream->net_seq_idx);
+				if (ret < 0) {
+					goto end_nosignal;
+				}
+			}
 		}
 
 		/* Get the right pipe where the stream will be sent. */
@@ -819,6 +821,7 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 			if (ret < 0) {
 				goto end_nosignal;
 			}
+			channel->streams_sent_to_relayd = true;
 		}
 		break;
 	}
@@ -1325,12 +1328,34 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 		}
 		ret = update_stream_stats(stream);
 		if (ret < 0) {
+			err = kernctl_put_subbuf(infd);
+			if (err != 0) {
+				if (err == -EFAULT) {
+					PERROR("Error in unreserving sub buffer\n");
+				} else if (err == -EIO) {
+					/* Should never happen with newer LTTng versions */
+					PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
+				}
+				ret = err;
+				goto end;
+			}
 			goto end;
 		}
 	} else {
 		write_index = 0;
 		ret = metadata_stream_check_version(infd, stream);
 		if (ret < 0) {
+			err = kernctl_put_subbuf(infd);
+			if (err != 0) {
+				if (err == -EFAULT) {
+					PERROR("Error in unreserving sub buffer\n");
+				} else if (err == -EIO) {
+					/* Should never happen with newer LTTng versions */
+					PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
+				}
+				ret = err;
+				goto end;
+			}
 			goto end;
 		}
 	}