Symptoms
Microsoft SQL Server performs dynamic memory management based on the memory requirements of the current load and activities on the system. On a Windows Server 2003 or a Windows XP or later version system,SQL Server can use the memory notification mechanisms that are provided by the QueryMemoryResourceNotification Windows API. On a Microsoft Windows 2000 Server-based system, SQL Server periodically calculates the free physical memory on the system by using the native Windows API. Based on this information from the QueryMemoryResourceNotification Windows API or from the memory calculation, SQL Server responds to the current memory situation on a specific system. This provides the following benefits:The system does not page out the working set of the SQL Server process.The necessary database pages are available in memory to reduce physical I/O needs.For more information, see the “Dynamic memory management” topic and the “Server memory options” topic in SQL Server Books Online.
Resolution
In 64-bit editions of SQL Server,various problems may occur. For example, the following problems may occur:The performance of SQL Serverdecreases suddenly.A computer that is running SQL Serverstops responding for a short time.A time-out occurs for applications that connect to SQL Server.Problems occur when you run even simple commands or use applications on the system.If you installed SQL Server 2005 Service Pack 2 (SP2) or a later version, one of the following error messages is logged in the SQL Server error log when these problems occur:
Error message 1

date time spid1s A significant part of sql server process memory has been paged out. This may result in a performance degradation. Duration: 0 seconds. Working set (KB): 1086400, committed (KB): 2160928, memory utilization: 50%.
Error message 2

date time spid1s A significant part of sql server process memory has been paged out. This may result in a performance degradation. Duration: 315 seconds. Working set (KB): 410156, committed (KB): 2201296, memory utilization: 18%.
Error message 3

date time spid1s A significant part of sql server process memory has been paged out. This may result in a performance degradation. Duration: 646 seconds. Working set (KB): 901904, committed (KB): 2215752, memory utilization: 40%.Additionally, a known problem exists in SQL Server in which you may receive an instance of this error message. The error message is logged in the SQL Server Error log during the startup process of SQL Server. The error message might be a false warning. Therefore, it might not indicate that working set trim has actually occurred. For more information, visit the following Microsoft Web site:
http://blogs.msdn.com/psssql/archive/2009/05/12/sql-server-reports-working-set-trim-warning-message-during-early-startup-phase.aspx(http://blogs.msdn.com/psssql/archive/2009/05/12/sql-server-reports-working-set-trim-warning-message-during-early-startup-phase.aspx) The Microsoft SQL Server support team has also observed additional error messages or warnings that are recorded in the SQL Server Error log or in the Windows Event logs. These messages resemble the following:

2009-05-05 15:43:56.01 ServerResource Monitor (0×13c43) Worker 0×0412C1E8 appears to be non-yielding on Node 0. Memory freed: 34152 KB. Approx CPU Used: kernel 171 ms, user 140 ms, Interval: 125093.2009-05-05 12:54:52.18 Server* *******************************************************************************2009-05-05 12:54:52.18 Server* BEGIN STACK DUMP:2009-05-05 12:54:52.18 Server*05/05/08 12:54:52 spid 02009-05-05 12:54:52.18 Server* Non-yielding Resource Monitor2009-05-05 12:54:52.18 Server* *******************************************************************************2009-06-10 09:13:53.44 Server* *******************************************************************************2009-06-10 09:13:53.44 Server* BEGIN STACK DUMP:2009-06-10 09:13:53.44 Server*06/10/09 09:13:53 spid 02009-06-10 09:13:53.44 Server* Non-yielding IOCP Listener2009-06-10 09:13:53.44 Server* *******************************************************************************2009-06-10 09:13:55.85 spid2sLazyWriter: warning, no free buffers found.2009-07-15 13:27:45.35 spid4sAppDomain xx (SQLCLR.dbo[runtime].xx) is marked for unload due to memory pressure.2009-07-15 13:27:45.35 spid4sAppDomain xx (SQLCLR.dbo[runtime].xx) unloaded.2009-07-15 13:37:51.42 LogonError: 17189, Severity: 16, State: 1.2009-07-15 13:37:51.42 LogonSQL Server failed with error code 0xc0000000 to spawn a thread to process a new login or connection. Check the SQL Server error log and the Windows event logs for information about possible related problems. [CLIENT: xx.xxx.xx.xx]Event Type: ErrorEvent Source: SQLBrowserEvent ID: 8Description: The SQLBrowser service was unable to process a client request. These additional error messages or warnings may appear together with the “A significant part of sql server process memory has been paged out” error message. In several instances, these additional error messages or warnings did not appear together with the error message.
If you notice one of these error messages or warnings, consider the SQL Server working set paging that is discussed in this article as one possible cause but not as the only cause. These additional error messages or warnings could be logged because of various other conditions or causes.