Hewlett-packard Development Company, L.p.

Paul David Gootherts

Douglas Vincent Larson

A method and apparatus for balancing processing loads to avoid starvation of threads is described. A method of load balancing evaluates the load and state of multiple processors. If at least one processor is in a source state and at least one processor is in a sink state, the processing load is balanced to avoid starvation. A thread is transferred from the heaviest loaded, source state processor to the least loaded, sink state processor. Each processor load and state is then reevaluated and, if needed, the load balancing with starvation avoidance repeated.

Load balancer with starvation avoidance

In an embodiment of the invention, a method for a memory-mapped lazy preemption control, the method includes: incrementing a counter value if an operating system attempts to involuntarily context switch out a thread and fails to context switch out the thread because the thread has a flag set; checking a counter value to determine a degree of abusiveness of a thread; and based upon the degree of abusiveness, determining if a voluntary contact switch out should be performed or should not be performed on the thread.

System for controlling context switch of deferred requests using counter and flag setting of thread accessing shared resource or entering code region

Systems, methods, and devices are provided for time measurement. One embodiment includes a method for measuring time on multiprocessor systems. The method includes allocating a memory space to a thread to be used to communicate with an operating system and saving a context switch count, an offset, and a scale factor, received from the operating system, in the memory space.

Time measurement using a context switch count, an offset, and a scale factor, received from the operating system

A method of and computer system for selecting a processor of a computer system on which to launch a processing thread is described. Each processor load is compared with a volunteer load of a volunteer information. If the processor load is lower than the volunteer load, the volunteer information is updated with the compared processor information. If the compared processor is the current volunteer and the compared processor load is higher than the volunteer load, the volunteer information is updated with the compared processor information.

Processing thread launching using volunteer information

In an embodiment of the invention, a method for lazy signal blocking, includes: when a program is going to enter a critical region of code where signals will be blocked, then setting an enabled flag and marking a signal mask with signals to be blocked, wherein the enabled flag and the signal mask are in a memory address space of the program; and when the program has left the critical region of code where signals will be blocked, then clearing the enabled flag.

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Santa Clara, CA, United States of America

Paul David Gootherts