OSA polling enhancements improve processing for TCP/IP inbound traffic that is destined to the z/TPF system. These enhancements also reduce the frequency of OSA read buffer overruns and balance inbound TCP/IP work better across all I-streams.

Each OSA-Express® connection that is defined to the z/TPF system has a set of defined OSA read buffers. Previously, the number of OSA read buffers per OSA-Express connection could be configured to be 16, 32, or 64. Because of the smaller buffer sizes, you might see buffer overruns, which can result in lost packets that are received from the network. With these enhancements, the number of OSA read buffers is increased to 128, which is the OSA card architectural maximum number of read buffers. The increased OSA read buffers can prevent future buffer overruns and inbound packets that are destined for the z/TPF system from being dropped. In addition, changes were made to ensure that OSA polling is called more frequently in some situations.

These enhancements also change the z/TPF scheduler to allow for more balanced distribution of TCP/IP inbound work across all I-streams.

For more information about APAR PJ45555, see the APEDIT.