This wait accumulates while SQL Server is waiting for the Operating System to return the procedure address so it can execute an extended stored procedure. These procedures are deprecated and should not be used for further development. These procedures run in unmanaged memory space therefore can cause SQL Server to crash if not written correctly. Some native functions still use these procedures so some values in this wait are expected. Note there is a bug in SQL Server 2008 and 2008 R2 where this wait will accumulate incorrectly. See link below
DBAs and Developers
- Ensure extended stored procedures are written using best practices (link below)
- Convert custom extended stored procedures to .net (CLR)
PREEMPTIVE_OS_GETPROCADDRESS: Are you confusing me?
How to use extended stored procedures
Common Language Runtime from the DBA Point of View