Patent ID: 9600349
Date: 2017-03-21
CPC Classifications: G06F

Claim:
1. In a computer system having a plurality of CPUs operatively coupled to one or more memory devices, a method for detecting a TASKS_RCU grace period whose quiescent states comprise a task undergoing a voluntary context switch, a task running in user mode, and a task running in idle-mode, said method comprising: building a runnable task list of all runnable tasks in said computer system, scanning said runnable task list in one or more scan passes; on each scan pass through said runnable task list, searching to identify quiescent state tasks that have passed through a quiescent state by either performing a voluntary context switch, running in user mode, or running in idle-mode, and if found, removing said quiescent state tasks from said runnable task list; said searching including identifying quiescent state tickless user mode tasks that have been running continuously in user mode on tickless CPUs that have not received a scheduling clock interrupt since commencement of said TASKS_RCU grace period; and if said runnable task list is empty, ending said TASKS_RCU grace period.