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PREEMPTIVE_XE_TARGETINIT

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Description:

This wait type is when a thread is switching to preemptive mode while creating an Extended Event session target.

(Books Online description: N/A)

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Added in SQL Server version:

2008

Removed in SQL Server version:

N/A

Extended Events wait_type value:

The map_key value in sys.dm_xe_map_values is 544 in 2008 and 2008 R2, 592 in 2012, and 608 in 2014 RTM. After 2014 RTM, you must check the DMV to get the latest value as some map_key values have changed in later builds.

Other information:

I have not seen this wait type be a noticeable contention point.

Known occurrences in SQL Server (list number matches call stack list):

  1. Creating a session target (in this case, as part of an ALTER EVENT SESSION operation)
  2. Creating a session target (in this case, as part of initializing the system_health session)

And other similar call stacks.

Abbreviated call stacks (list number matches known occurrences list):

  1. SOS_Task::PopWait+b1
    SOS_ExternalAutoWait::~SOS_ExternalAutoWait+7a
    XE_ActualTargetEntry::Create+2f5
    XE_Session::AddTarget+197
    XE_Engine::AddTarget+37
    CXE_Target::AddTarget+2f2
    XEventController::AlterEventSession+518
    CStmtCreateEventSession::XretExecute+126
    CMsqlExecContext::ExecuteStmts<0,1>+8bd
    CMsqlExecContext::FExecute+a58
    CSQLSource::Execute+86c
    process_request+a57
    process_commands+4a3
    SOS_Task::Param::Execute+21e
    SOS_Scheduler::RunTask+ab
  2. SOS_Task::PopWait+b1
    SOS_ExternalAutoWait::~SOS_ExternalAutoWait+7a
    XE_ActualTargetEntry::Create+2f5
    XE_Session::AddTarget+242
    XE_Engine::AddTarget+37
    EventSessionMgr::StartSession+217
    EventSessionMgr::Init+c5
    DiagEventSessionMgr::Init+14a
    DiagnoseComponentMgr::Execute+3fa
    SystemHealthMonitor+12b
    SystemHealthMonitorThread+94
    SOS_Task::Param::Execute+21e
    SOS_Scheduler::RunTask+ab