Non-Paged Pool Is Exhausted by Afd

Under certain circumstances, the heavy use of WinSock programs can cause non-paged pool memory to become exhausted. This behavior is likely to occur if the WinSock program is dealing with both Out-of-Band (MSG_OOB) and normal TCP traffic. This situation can cause various error messages, poor performance, and system hangs. Examples of possible error messages include: Other events may not work and may generate status code 1450 ("Insufficient System Resources").

If the WinSock program does not correctly post a Receive to collect the incoming data from WinSock, Afd may endlessly buffer the data and use up all non-paged memory. Afd should check the MaxBufferredReceiveBytes value for the socket and then not buffer more than this value.

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix should have the following file attributes or later:

To work around this issue, do not use MSG_OOB data in your WinSock program. Use a separate socket for urgent data.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

You can observe this problem with Performance Monitor. Log the Non-Paged Pool Bytes item under Memory Object, and watch for the value to grow to 20-40 MB.