Method and system for allocating entitled processor cycles for preempted virtual processors

Abstract

A method, apparatus, system, and signal-bearing medium that, in an embodiment, calculate a preemption credit for a partition if a virtual processor is preempted and the partition is unable to receive an entitled capacity of physical processor cycles during a dispatch window. The preemption credit is the portion of the entitled capacity that the partition is unable to receive. As long as the partition has a remaining preemption credit, in subsequent dispatch windows, a portion of the preemption credit is allocated to the virtual processor, and the preemption credit is reduced. In this way, in an embodiment, shared processor partitions may be ensured of receiving their entitled allocation of processor cycles.

Description

technical field [0001] Embodiments of the invention generally relate to computers. In particular, embodiments of the invention generally relate to allocating virtual processors in a shared processor partition of a computer system. Background technique [0002] The development of the EDVAC computer system in 1948 is often cited as the beginning of the computer age. Since then, computer systems have grown into extremely sophisticated devices, and computer systems can appear in many different settings. A computer system typically includes a combination of hardware, such as semiconductors and circuit boards, and software, also known as a computer program. With the advancement of semiconductor technology and computer architecture, the performance of computer hardware has become higher, and more sophisticated and complex computer software has been developed to take advantage of the higher performance of hardware, resulting in today's computer systems that are more powerful than ...

AI Technical Summary

Problems solved by technology

While this technique guarantees that partitions will receive their due capabilities over the dispatch window, it also incurs a large switching overhead and makes it difficult for the hypervisor to maintain processor closeness, resulting in performance degradation

[0011] Therefore, there is no better way to balance the performance goal of fewer dispatches with the functional goal of guaranteeing the virtual processor's fair share of CPU cycles, and logically partitioned systems will continue to struggle to overcome performance issues

Images