To create a session with advanced options, fill in the relevant parameters and press '''Ok'''. Upon successful operation a new session will be created and added under the tree node '''Sessions'''.
+==== Creating a Snapshot Tracing Session ====
+LTTng Tools version v2.3.0 introduces the possibility to create snapshot tracing sessions. After starting tracing the trace events are not stored on disk or over the network. They are only transfered to disk or over the network when the user records a snapshot. To create such a snapshot session, open the trace session dialog as described in chapter [[#Creating a Tracing Session | Creating a Tracing Session]].
+
+[[Image:images/LTTng2CreateSessionDialog_Snapshot.png]]
+
+Fill in all necessary information, select checkbox for '''Snapshot Mode''' and press '''Ok'''. By default, the location for the snapshot output will be on the host where the host is located.
+
+Refer to chapter [[#Recording a Snapshot | Recording a Snapshot]] for how to create a snapshot.
+
==== Enabling Channels - General ====
Enabling channels can be done using a session tree node when the domain hasn't be created in the session or, alternatively on a domain tree node of a session in case the domain is already available.
Upon successful operation, the tracing session will be '''ACTIVE''' and the icon of the session will be updated.
+==== Recording a Snapshot ====
+
+LTTng Tools version v2.3.0 introduces the possibility to create snapshot tracing sessions. After creating a snapshot session (see [[#Creating a Snapshot Tracing Session | Creating a Snapshot Tracing Session]]) and starting tracing (see [[#Start Tracing | Start Tracing]]) it possible to record snapshots. To record a snapshot select one or more sessions and press the '''Record Snapshot''' button. Alternatively, press the right mouse button on the session tree nodes. A context-sensitive menu will show. Then select the '''Recored Snapshot''' menu item.
+
+[[Image:images/LTTng2RecordSnapshotAction.png]]
+
+This action can be executed many times. It is possible to import the recorded snpshots to a tracing project. The trace session might be '''ACTIVE''' or '''INACTIVE''' for that. Refer to section [[#Importing Session Traces to a Tracing Project | Importing Session Traces to a Tracing Project]] on how to import a trace to a tracing project.
+
==== Stop Tracing ====
-To stop tracing, select one or more sessions to stop in the Control View and press the '''Stop''' button. Alternatively, click the right mouse button on the session tree nodes. A context-sensitive menu will show. Then select the '''Stop''' menu item.
+To stop tracing, select one or more sessions to stop in the Control View and press the '''Stop''' button. Alternatively, click the right mouse button on the session tree node. A context-sensitive menu will show. Then select the '''Stop''' menu item.
[[Image:images/LTTng2StopTracingAction.png]]
** '''Log Level''': The log level of the event.
* '''Session''' Properties
** '''Session Name''': The name of the Session.
-** '''Session Path''': The path on the remote host where the traces will be stored.
+** '''Session Path''': The path on the remote host where the traces will be stored. (Not shown for snapshot sessions).
** '''State''': The state of the session ('''ACTIVE''' or '''INACTIVE''')
+** '''Snapshot ID''': The snapshot ID. (Only shown for snapshot sessions).
+** '''Snapshot Name''': The name of the snapshot output configuration. (Only shown for snapshot sessions).
+** '''Snapshot Path''': The path where the snapshot session is located. (Only shown for snapshot sessions).
* '''Domain''' Properties
** '''Domain Name''': The name of the domain.
** '''Buffer Type''': The buffer type of the domain.
== Control Flow View ==
-The '''''Control Flow View''''' is a LTTng-specific view that shows per-process events graphically. To enable it, select ''Control Flow'' under ''LTTng'' within the ''Show View'' window ('''Window''' -> '''Show View''' -> '''Other...'''):
+The '''''Control Flow''''' view is a LTTng-specific view that shows per-process events graphically. To enable it, select ''Control Flow'' under ''LTTng'' within the ''Show View'' window ('''Window''' -> '''Show View''' -> '''Other...'''):
[[Image:images/Cfv_show_view.png]]
[[Image:images/Cfv_global.png]]
-The view is divided into the following important sections: '''<span style="color: #C84545;">process tree</span>''', '''<span style="color: #A1C81A;">process TID, PTID and birth time</span>''', '''<span style="color: #67A3DC;">states flow</span>''' and the '''<span style="color: #AD77D7;">toolbar</span>'''.
+The view is divided into the following important sections: '''process tree and information''', '''control flow''' and the '''toolbar'''.
The following sections provide detailed information for each part of the Control Flow View.
-=== Process tree and informations ===
+=== Process tree and information ===
Processes are organized as a tree within this view. This way, child and parent processes are easy to identify.
The layout is based on the states computed from the trace events.
-A given process may be shown at different places within the tree since the nodes are '''unique (TID, birth time) couples'''. This means that if process B of parent A dies, you'll still see it in the tree. If process A forks process B again, it will be shown as a different node since it won't have the same birth time (and probably not the same TID). This has the advantage that the tree, once loaded, never changes: horizontal scrolling within the [[#States flow|states flow]] remains possible.
+A given process may be shown at different places within the tree since the nodes are '''unique (TID, birth time) couples'''. This means that if process B of parent A dies, you'll still see it in the tree. If process A forks process B again, it will be shown as a different node since it won't have the same birth time (and probably not the same TID). This has the advantage that the tree, once loaded, never changes: horizontal scrolling within the [[#Control flow|control flow]] remains possible.
The TID column shows the process node's '''thread ID''' and the PTID column shows its '''parent thread ID''' (nothing is shown if the process has no parent).
-=== States flow ===
+=== Control flow ===
This part of the Control Flow View is probably the most interesting one. Using the mouse, you can navigate through the trace (go left, right) and zoom on a specific region to inspect its details.
This dark yellow is what you'll see most of the time since scheduling puts processes on hold while others run.
-The vertical blue line is the '''current selection indicator'''. When a time range is selected, the region between the begin and end time of the selection will be shaded.
+The vertical blue line with T1 above it is the '''current selection indicator'''. When a time range is selected, the region between the begin and end time of the selection will be shaded and two lines with T1 and T2 above will be displayed. The time stamps corresponding to T1, T2 and their delta are shown in the status line when the mouse is hovering over the control flow.
+
+Arrows can be displayed that follow the execution of each CPU across processes. The arrows indicate when the scheduler switches from one process to another for a given CPU. The CPU being followed is indicated on the state tooltip. When the scheduler switches to and from the idle process, the arrow skips to the next process which executes on the CPU after the idle process. Note that an appropriate zoom level is required for all arrows to be displayed.
+
+The display of arrows is optional and can be toggled using the '''Hide Arrows''' toolbar button. It is also possible to follow a CPU's execution across state changes and the scheduler's process switching using the '''Follow CPU Forward/Backward''' toolbar buttons.
==== Using the mouse ====
* the process name
* the pointed state name
+* the CPU (if applicable)
+* the system call name (if applicable)
* the pointed state date and start/stop times
* the pointed state duration (seconds)
The Control Flow View '''toolbar''', located at the top right of the view, has shortcut buttons to perform common actions:
-[[Image:images/Cfv_toolbar.png]]
-
-The '''Previous event''' and '''Next event''' buttons update the current time indicator so that it's on the previous or next event.
-
-The '''Previous process''' and '''Next process''' buttons select the previous and next process node within the process tree.
-
-The '''Process filter''' buttons opens a new dialog box for configuring the processes to show.
-
-[[Image:images/LTTng2_CFV_Filter.png]]
+{|
+| [[Image:images/filter_items.gif]]
+| Show View Filter
+| Opens the process filter dialog
+|-
+| [[Image:images/show_legend.gif]]
+| Show Legend
+| Displays the states legend
+|-
+| [[Image:images/home_nav.gif]]
+| Reset the Time Scale to Default
+| Resets the zoom window to the full range
+|-
+| [[Image:images/prev_event.gif]]
+| Select Previous Event
+| Selects the previous state for the selected process
+|-
+| [[Image:images/next_event.gif]]
+| Select Next Event
+| Selects the next state for the selected process
+|-
+| [[Image:images/prev_menu.gif]]
+| Select Previous Process
+| Selects the previous process
+|-
+| [[Image:images/next_menu.gif]]
+| Select Next Process
+| Selects the next process
+|-
+| [[Image:images/zoomin_nav.gif]]
+| Zoom In
+| Zooms in on the selection by 50%
+|-
+| [[Image:images/zoomout_nav.gif]]
+| Zoom Out
+| Zooms out on the selection by 50%
+|-
+| [[Image:images/hide_arrows.gif]]
+| Hide Arrows
+| Toggles the display of arrows on or off
+|-
+| [[Image:images/follow_arrow_bwd.gif]]
+| Follow CPU Backward
+| Selects the previous state following CPU execution across processes
+|-
+| [[Image:images/follow_arrow_fwd.gif]]
+| Follow CPU Forward
+| Selects the next state following CPU execution across processes
+|}
== Resources View ==
+
This view is specific to kernel trace. To open it, go in '''Window''' -> '''Show View''' -> '''Other...''' and select '''LTTng/Resources''' in the list.
[[Image:images/Rv_example.png| Example of resources view with all trace points and syscalls enabled]]
The Resources View '''toolbar''', located at the top right of the view, has shortcut buttons to perform common actions:
-[[Image:images/Rv_toolbar.png]]
-
-The '''Previous event''' and '''Next event''' buttons update the current time indicator so that it's on the previous or next event.
-
-The '''Previous resource''' and '''Next resource''' buttons select the previous and next resource node within the resource tree.
+{|
+| [[Image:images/show_legend.gif]]
+| Show Legend
+| Displays the states legend
+|-
+| [[Image:images/home_nav.gif]]
+| Reset the Time Scale to Default
+| Resets the zoom window to the full range
+|-
+| [[Image:images/prev_event.gif]]
+| Select Previous Event
+| Selects the previous state for the selected resource
+|-
+| [[Image:images/next_event.gif]]
+| Select Next Event
+| Selects the next state for the selected resource
+|-
+| [[Image:images/prev_menu.gif]]
+| Select Previous Resource
+| Selects the previous resource
+|-
+| [[Image:images/next_menu.gif]]
+| Select Next Resource
+| Selects the next resource
+|-
+| [[Image:images/zoomin_nav.gif]]
+| Zoom In
+| Zooms in on the selection by 50%
+|-
+| [[Image:images/zoomout_nav.gif]]
+| Zoom Out
+| Zooms out on the selection by 50%
+|}
== LTTng Kernel Events Editor ==