Quick Start - Enabling Data Capture on Process Launch

  • Article

Enabling data capture on process launch guarantees that there will be no loss of allocation information or history. Take the following steps to enable data capture on process launch:

  1. If Windows Sidebar is running, open Windows Task Manager and end any sidebar.exe processes.

  2. Open an elevated command prompt. It is recommended to identify a single directory from which WPA is run and change to that directory.

  3. From the command prompt enter the following:

    C:\etl> xperf -on Base -BufferSize 1024  -MinBuffers 10 -MaxBuffers 16

    By default, WPA will automatically turn on the "NT Kernel Logger" which collects kernel events. The kernel group "Base" will trigger the collection of events from the following event providers:

    Option Usage
    PROC_THREAD
    		 Lists process and thread create/delete events
    LOADER
    		 Shows kernel and user mode load and unload events
    DISK_IO
    		 Tracks disk activity for the session
    HARD_FAULTS
    		 Lists hard page faults
    PROFILE
    		 Creates a CPU sample profile
    MEMINFO
    		 Captures memory list information

  4. Next, enter the following on a single line:

    C:\etl> xperf -start HeapSession -heap -PidNewProcess "C:\Program Files\Windows Sidebar\sidebar.exe" -BufferSize 1024 -MinBuffers 128 -MaxBuffers 128 -stackwalk HeapAlloc+HeapRealloc

    The following table explains each of the commands, parameters and options employed.

    Option, command or parameter Usage
    xperf
    		 Runs the main xperf program with the specified parameters and options.
    -start HeapSession
    		 Initializes a tracing session or logger session. In this case the session is named "HeapSession".
    -heap
    		Identifies HeapSession as a heap trace.
    -PidNewProcess
    		Initializes a process. In this case the Windows Sidebar will be started.
    -BufferSize
    		 Sets the buffer size where the event data will be stored. 1024K is an optimum buffer size. By default WPA will use 64K.
    -MinBuffers
    		 Sets the minimum number of buffers for event data storage. MinBuffers should be equal to MaxBuffers in order to guarantee consistency between traces.
    -MaxBuffers
    		 MaxBuffers should be allocated conservatively because buffers are allocated from non-paged memory, a finite system resource.
    -stackwalk
    		 Initializes the stackwalk facility to collect allocation and de-allocation information and associate that information with specific threads.
    HeapAlloc+HeapRealloc
    		 Identifies specific heap events to be captured and presented by the stackwalk facility.

  5. At this point the sidebar will open on the desktop.

  6. In the command window, enter the following on a single line:

    C:\etl> xperf -stop -stop HeapSession -d heapTrace.etl

    The following table explains each of the commands, parameters and options:

    Option, Command or Parameter Usage
    xperf
    		 Runs the main xperf program with the specified parameters and options.
    -stop HeapSession
    		 Indicates a session will be ended. In this case, end the session "HeapSession".
    -d heapTrace.etl
    		 Merges traces produced in the session into the trace file "heapTrace.etl".

    For more information on WPA start and stop options, use the command line query:

    C:\etl> xperf -help start
C:\etl> xperf -help stop