Extending Enhanced I/O Error Handling (EEH) Framework in AIX to Handle Long Recovery Times
Original Publication Date: 2004-Aug-09
Included in the Prior Art Database: 2004-Aug-09
Disclosed is a method of extending EEH (Enhanced I/O Error Handling) recovery time for any device driver that follows AIX's multifunction programming model with respect to EEH. Current state machine for the EEH recovery assumes instantaneous execution of each recovery step. This poses a problem for those device drivers that need to perform a certain cleanup task during the EEH recovery, and the cleanup task can take up to several minutes. The EEH state machine is extended in such a way that it allows for longer recovery times. Specifically, four new states are added to the state machine that permit waiting from the interrupt environment combined with a retry protocol. The retry protocol requires storing and restoring some context information before each retry. Thus, the invention is the next step forward in expanding the scope of EEH recovery in AIX.