X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=doc%2Fman%2Flttng.1;h=12ca33d6fbcdecc7faa2019c435acae6ea1fe91e;hb=fb14d0d8da366c09452d1f8c43268e46dfb7da40;hp=ef73b062cd558ea5017957c38ea475adc29c8066;hpb=516f6cbe18eb229593a41eef7d0ed2567673d603;p=lttng-tools.git

diff --git a/doc/man/lttng.1 b/doc/man/lttng.1
index ef73b062c..12ca33d6f 100644
--- a/doc/man/lttng.1
+++ b/doc/man/lttng.1
@@ -402,7 +402,8 @@ Apply to the user-space tracer
 Discard event when subbuffers are full (default)
 .TP
 .BR "\-\-overwrite"
-Flight recorder mode : overwrites events when subbuffers are full
+Flight recorder mode: overwrites events when subbuffers are full. The
+number of subbuffer must be 2 or more.
 .TP
 .BR "\-\-subbuf-size SIZE"
 Subbuffer size in bytes {+k,+M,+G}.
@@ -442,6 +443,8 @@ Use shared buffer for the whole system (\-k only)
 .BR "\-C, \-\-tracefile-size SIZE"
 Maximum size of each tracefile within a stream (in bytes).
 0 means unlimited. (default: 0)
+Note: traces generated with this option may inaccurately report
+discarded events as of CTF 1.8.
 .TP
 .BR "\-W, \-\-tracefile-count COUNT"
 Used in conjunction with \-C option, this will limit the number of files
@@ -587,6 +590,11 @@ running applications can be found under columns "PID" and "LWP" of the
   '$ctx.vtid == 1234'
 .fi
 
+Context information is available to all filters whether or not the add-context
+command has been used to add it to the event's channel, as long as the context
+field exists for that domain. For example, the filter examples given above will
+never fail to link: no add-context is required for the event's channel.
+
 .TP
 .BR "\-x, \-\-exclude LIST"
 Add exclusions to UST tracepoints:
@@ -741,8 +749,10 @@ List available domain(s)
 Load tracing session configuration
 
 If NAME is omitted, all session configurations found in both the user's session
-configuration directory and the system session configuration directory will be
-loaded.
+configuration directory (default: ~/.lttng/sessions/) and the system session
+configuration directory (default: /etc/lttng/sessions/) will be loaded. Note
+that the sessions in the user directory are loaded first and then the system
+wide directory are loaded.
 
 .B OPTIONS:
 
@@ -754,7 +764,8 @@ Show summary of possible options and commands.
 Load all session configurations (default).
 .TP
 .BR "\-i, \-\-input-path PATH"
-Specify the input path for session configurations.
+Specify the input path for session configurations. This overrides the default
+session configuration directory.
 .TP
 .BR "\-f, -\-force"
 Overwrite current session configuration(s) if a session of the same name
@@ -768,8 +779,12 @@ already exists.
 Save tracing session configuration
 
 If SESSION is omitted, all session configurations will be saved to individual
-\fB.lttng\fP files under the user's session configuration directory. The
-default session configuration file naming scheme is \fBSESSION.lttng\fP.
+\fB.lttng\fP files under the user's session configuration directory (default:
+~/.lttng/sessions/). The default session configuration file naming scheme is
+\fBSESSION.lttng\fP.
+
+For instance, a user in the tracing group saving a session from a root session
+daemon will save it in her/his user directory.
 
 .B OPTIONS:
 
@@ -781,7 +796,8 @@ Show summary of possible options and commands.
 Save all session configurations (default).
 .TP
 .BR "\-o, \-\-output-path PATH"
-Specify the output path for saved sessions (default: ~/.lttng/sessions/).
+Specify the output path for saved sessions. This overrides the default session
+configuration directory.
 .TP
 .BR "\-f, -\-force"
 Overwrite session configuration file if session name clashes.
@@ -872,6 +888,10 @@ Name of the snapshot's output.
 Maximum size in bytes of the snapshot. The maxium size does not include the
 metadata file. Human readable format is accepted: {+k,+M,+G}. For instance,
 \-\-max-size 5M
+
+The minimum size of a snapshot is computed by multiplying the total amount of
+streams in the session by the largest subbuffer size. This is to ensure
+fairness between channels when extracting data.
 .TP
 .BR "\-C, \-\-ctrl-url URL"
 Set control path URL. (Must use -D also)