Filtering traces

QNX Toolkit1.1QNX Toolkit User's GuideDeveloperSetup

Using the filters, you can globally restrict which owners and events are displayed in the System Profiler dashboard views.

There are three tabs in the FILTERS view:

  • OWNERS — A filter that lets you check boxes to choose the owners to include in the displayed results.
  • EVENTS — A filter that lets you select specific event classes or types to include in the results. You must expand class entries to see individual types.
  • PRESETS — A set of commands that can enable or disable certain elements on other filters.

Owners

You can use OWNERS to filter for processes and threads that you are interested in.

To filter the owners:

  1. Click QNX SYSTEM PROFILER, then select a .kev file.
  2. Click FILTERS > OWNERS.
  3. Check the specific owners to include.
By way of example, the following screenshot shows how the Event Table and the Timeline views update when filtering on the slogger2 process:

Events

You can use EVENTS to filter Event Table information.

To filter the events:

  1. Click QNX SYSTEM PROFILER, then select a .kev file.
  2. Click FILTERS > EVENTS.
  3. Check the specific events to include.
By way of example, the following screenshot shows how the Event Table view updates to show only COMM class events:

Presets

You can use PRESETS to apply a pre-selected set of filters that apply to specific elements. For example, you can select a preset that shows you only filters for CPU usage elements, or only information for elements involved in IPC activity.

To apply the filter presets:

  1. Click QNX SYSTEM PROFILER, then select a .kev file.
  2. Click FILTERS > PRESETS.
  3. Check the specific presets, then select one of the three options:
    • Click the Show Only icon to filter some elements and hide others.
    • Click the Show More icon to add more filter elements to the current filter.
    • Click the Hide icon to hide the filter elements from view.
By way of example, the following screenshot shows how the Timeline view updates to show only IPC Activity (Current):

The following table describes the possible preset commands you can use:

Preset Command Description
CPU Usage Top 10 Threads Show the top 10 threads with the most CPU usage.
CPU Usage Top N Threads Show the top number of threads with the most CPU usage. Enter a number when prompted.
CPU Usage Top 20% Threads Show the threads in the top 20% of CPU usage.
CPU Usage All Threads Show all threads with associated CPU usage.
IPC Activity (Current) Show IPC activity for events selected in the Event Table.
Kernel Idle Threads Display idle threads.
Interrupts Display interrupts and interrupt handlers.
Processes (Current) Show only processes that are not threads (e.g. IPI_64, SND_PULSE_EXE).
Threads (Current) Show only threads.
State Activity Display elements involved in state change activity and interrupts activity.
Text Match (Owners) Show only the processes and events that correspond to text-based search. Enter a string when prompted.

Saving filtered traces

You can save a partial trace.kev file based on user filters (time range, zoom region, full selection range, as well as owner and event filters).

To save a filtered trace:

  1. Right-click the trace.kev file in the System Profiler.
  2. Click Save Filtered File:

  3. Select the time range: Current Zoom, Manually Enter, or Full.
  4. Select filters to apply: Both, Event, Owner, or None.
  5. Save the filtered file.
    You are prompted with the following notification:

  6. Select Yes to open the filtered file.
The following table describes the possible time ranges:
Heading Description
Current Zoom Use current zoom region of the trace.
Manually Enter Manually enter time range.
Full Entire time range of the trace.
The following table describes the possible filters:
Heading Description
Both Apply both owner and event filters.
Event Apply only event filters.
Owner Apply only owner filters.
None Apply no filters.

Essential events:

Essential events always display regardless of the applied filtering settings. As a result, the time range of a saved .kev file is sometimes longer than the selected time range. Furthermore, some essential events cannot be filtered out and, thus, the number of events in the new .kev file may be greater than expected.

The following list comprises the essential events:
  1. _NTO_TRACE_SYS_APS_NAME.
  2. _NTO_TRACE_SYS_APS_BUDGETS.
  3. _NTO_TRACE_PROCTHREAD_NAME.
  4. _NTO_TRACE_PROCCREATE_NAME.
  5. _NTO_TRACE_THRUNNING.
  6. _NTO_TRACE_THREADY.
  7. _NTO_TRACE_CONTROL class; go to Control class:_NTO_TRACE_CONTROL in the Events and the Kernel chapter of the System Analysis Toolkit User's Guide.
  8. The procnto utility or its threads; go to the procnto utility in the Utilities Reference chapter of Utilities & Libraries for more information.

For more information about events, go to Table of events in the Current Trace Events and Data chapter of the System Analysis Toolkit User's Guide.

Filter synchronization

Each dashboard View in the System Profiler can be synced or desynced from the global filters (Owners, Events, Presets). You can also sync or desync individual views with the other views (eg., desync the CPU Usage view so that zooming in/out doesn't impact what's shown in the Timeline view).

Each System Profiler view has filter synchronization capabilities. By way of example, you can follow the procedure to sync or desync the CPU Usage View.

To change the CPU Usage view synchronization behavior with the other views:

  • From the CPU Usage view, click the Sync/Desync With Other Views icon. When the views are synced, changes made to the zoom or filtering settings are reflected on any other synched views.

To change the global synchronization behavior

  • From the CPU Usage view, click the Sync/Desync Global Filters icon. When the views are synced, changes made to the global filters show up in the CPU Usage view.
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