update comment

git-svn-id: http://ltt.polymtl.ca/svn@3114 04897980-b3bd-0310-b5e0-8ef037075253

diff --git a/trunk/lttv/ltt/tracefile.c b/trunk/lttv/ltt/tracefile.c
index 2f530accc0e748bbea3c61bd2cbb08baeb42eedb..1d411e3e3f2ad94cc31e60e1bdbc53c35956534d 100644 (file)
--- a/trunk/lttv/ltt/tracefile.c
+++ b/trunk/lttv/ltt/tracefile.c
@@ -772,7 +772,13 @@ LttTrace *ltt_trace_open(const gchar *pathname)
     goto metadata_error;
   }
 
-  /* Get the trace information for the control/metadata_0 tracefile */
+  /*
+   * Get the trace information for the control/metadata_0 tracefile.
+   * Getting a correct trace start_time and start_tsc is insured by the fact
+   * that no subbuffers are supposed to be lost in the metadata channel.
+   * Therefore, the first subbuffer contains the start_tsc timestamp in its
+   * buffer header.
+   */
   g_assert(group->len > 0);
   tf = &g_array_index (group, LttTracefile, 0);
   header = (ltt_subbuffer_header_t *)tf->buffer.head;