RMF reports show a significant increase in false contention

Problem

The Resource Measurement Facility (RMF) reports might show a significant increase in false contention for global ENQs. When RESERVEs have been converted to GRS Global ENQs, the ENQs may take longer to resolve if the ISGLOCK structure is too small to process each global ENQ independently.

Action

If this occurs, increase the size of the ISGLOCK structure.

See the z/OS® MVS Planning: Global Resource Serialization documentation, for information on GRS, including guidelines about how to resize the ISGLOCK structure.