From e50e81d3670e2420810ff62a036a7303b578e1e1 Mon Sep 17 00:00:00 2001 From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?= Date: Fri, 28 Jul 2017 10:42:46 -0400 Subject: [PATCH] Only print relevant session statistics in channel listing MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Jérémie Galarneau --- src/bin/lttng/commands/list.c | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) diff --git a/src/bin/lttng/commands/list.c b/src/bin/lttng/commands/list.c index 8705a4446..8f07bb2da 100644 --- a/src/bin/lttng/commands/list.c +++ b/src/bin/lttng/commands/list.c @@ -57,6 +57,9 @@ enum { static struct lttng_handle *handle; static struct mi_writer *writer; +/* Only set when listing a single session. */ +static struct lttng_session listed_session; + static struct poptOption long_options[] = { /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */ {"help", 'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0}, @@ -1215,8 +1218,6 @@ static void print_channel(struct lttng_channel *channel) MSG("%sblocking timeout: %" PRId64 " µs", indent6, blocking_timeout); MSG("%strace file count: %" PRIu64, indent6, channel->attr.tracefile_count); MSG("%strace file size: %" PRIu64 " bytes", indent6, channel->attr.tracefile_size); - MSG("%sdiscarded events: %" PRIu64, indent6, discarded_events); - MSG("%slost packets: %" PRIu64, indent6, lost_packets); switch (channel->attr.output) { case LTTNG_EVENT_SPLICE: MSG("%soutput: splice()", indent6); @@ -1225,6 +1226,31 @@ static void print_channel(struct lttng_channel *channel) MSG("%soutput: mmap()", indent6); break; } + + if (!listed_session.snapshot_mode) { + /* + * The lost packet count is omitted for sessions in snapshot + * mode as it is misleading: it would indicate the number of + * packets that the consumer could not extract during the + * course of recording the snapshot. It does not have the + * same meaning as the "regular" lost packet count that + * would result from the consumer not keeping up with + * event production in an overwrite-mode channel. + * + * A more interesting statistic would be the number of + * packets lost between the first and last extracted + * packets of a given snapshot (which prevents most analyses). + */ + goto skip_stats_printing; + } + + if (!channel->attr.overwrite) { + MSG("%sdiscarded events: %" PRIu64, indent6, discarded_events); + } else { + MSG("%slost packets: %" PRIu64, indent6, lost_packets); + } +skip_stats_printing: + return; } /* @@ -1584,6 +1610,8 @@ static int list_sessions(const char *session_name) active_string(sessions[i].enabled), snapshot_string(sessions[i].snapshot_mode)); MSG("%sTrace path: %s\n", indent4, sessions[i].path); + memcpy(&listed_session, &sessions[i], + sizeof(listed_session)); break; } } else { @@ -1593,7 +1621,7 @@ static int list_sessions(const char *session_name) snapshot_string(sessions[i].snapshot_mode)); MSG("%sTrace path: %s", indent4, sessions[i].path); if (sessions[i].live_timer_interval != 0) { - MSG("%sLive timer interval (usec): %u", indent4, + MSG("%sLive timer interval: %u µs", indent4, sessions[i].live_timer_interval); } MSG(""); -- 2.34.1