[dba-SQLServer] gracefully shut down a process

Is there any way to gracefully shut down a running query QUICKLY?

I have a stored procedure running which really should have completed long ago.  This SP calculates a 
hash value for a set of concatenated text fields and stores the result back into a binary hash field.

I ran this thing 3 times today on other tables of roughly the same number of records and they 
completed in perhaps 15 minutes.  For whatever reason, this one has been running 1.5 hours.  These 
process bogs down the server such that very little real work can get done with it running.

So I need to tell SQL Server to just stop!  Store what you have calculated and stop!

Any way to do this?  Without killing the table being written to.

-- 
John W. Colby
www.ColbyConsulting.com