Controlling a rate at which adapter interruption requests are processed

A computer program product of controlling interrupt processing in a computing environment, the computer program product comprising:

• a non-transitory computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:
• presenting an interrupt request by an adapter of the computing environment to an operating system, the operating system to process one or more set event indicators corresponding to the interrupt request, and wherein an interruptions mode set for the adapter is a single interruptions mode;
• and
• based on the presenting, automatically changing the interruptions mode set for the adapter to a no interruptions mode, wherein another interrupt request is not presented to the operating system but event indicators for one or more other interrupt requests are set to be processed by the operating system.

A computer system for controlling interrupt processing in a computing environment, the computer system comprising:

• a memory;
• and
• a processor in communications with the memory, wherein the computer system is configured to perform a method, said method comprising:
• determining that a CPU-facing pending indicator has been set indicating an interrupt request by an adapter of the computing environment;
• presenting the interrupt request to a selected operating system, the selected operating system to process one or more set event indicators corresponding to the interrupt request and one or more other set event indicators corresponding to one or more other interrupt requests;
• resetting, in response to the presenting, the CPU-facing pending indicator indicating to one or more processors that an interrupt request is not pending, wherein a hub-facing pending indicator remains set to indicate to a hub an interrupt is already presented and to suppress other interrupt requests from being made pending;
• resetting the hub-facing pending indicator, based on a change in a control mode to allow another interrupt request to be made pending, the change in control mode based on a determination that event notifications are arriving at a rate faster than can be currently handled and that another interrupt request is to be presented allowing at least one other processor to process set event indicators;
• determining that the CPU-facing pending indicator has been set indicating another interrupt request has been made pending;
• and
• presenting the another interrupt request to one operating system of one or more operating systems.

A method of controlling interrupt processing in a computing environment, the method comprising:

• determining, by a processor of the computing environment, that a CPU-facing pending indicator has been set indicating an interrupt request by an adapter of the computing environment;
• presenting, by the processor, the interrupt request to a selected operating system, the selected operating system to process one or more set event indicators corresponding to the interrupt request and one or more other set event indicators corresponding to one or more other interrupt requests;
• resetting, based on the presenting, the CPU-facing pending indicator indicating to one or more processors that an interrupt request is not pending, wherein a hub-facing pending indicator remains set to indicate to a hub an interrupt is already presented and to suppress other interrupt requests from being made pending;
• resetting the hub-facing pending indicator, based on a change in a control mode to allow another interrupt request to be made pending, the change in control mode based on a determination that event notifications are arriving at a rate faster than can be currently handled and that another interrupt request is to be presented allowing at least one other processor to process set event indicators;
• determining, by the processor or another processor, that the CPU-facing pending indicator has been set indicating another interrupt request was made pending;
• and
• presenting, by the processor or another processor, the another interrupt request to one operating system of one or more operating systems.