solve high stolen memory
You could try querying various dmvs with the following script.

SELECT TEXT,
   request_time,
   grant_time,
   query_cost,
   timeout_sec,
   wait_order,
   wait_time_ms,
   group_id,
   requested_memory_kb,
   granted_memory_kb,
   required_memory_kb,
   used_memory_kb,
   max_used_memory_kb,
   ideal_memory_kb,
   query_plan,
   'all information &gt;',
   *
FROM   sys.dm_exec_query_memory_grants qmg
   OUTER APPLY sys.dm_exec_sql_text(sql_handle) st
OUTER APPLY sys.dm_exec_query_plan(plan_handle) qp


It queries the following dmvs for information:  


sys.dm_exec_query_memory_grants  
sys.dm_exec_sql_text  
sys.dm_exec_query_plan  


This script was handed over to me by Ramesh Meyyappan at a course on "SQL Server Performance Tuning and Optimisation" at Microsoft SA, Wallisellen, Switzerland.