Patent ID: 10613913

Abstract:
A funnel locking technique for normal read-copy update (RCU) grace period requests. Based on a calculated future normal RCU grace period, a traversal is initiated of a funnel lock embodied as a hierarchical tree of nodes. The funnel-lock traversal starts at an initial node whose lock is held throughout the funnel-lock traversal. For each node accessed during the funnel-lock traversal that is not the initial node, a lock on the node is held while accessing that node. For each accessed node, the funnel-lock traversal is terminated if the future normal RCU grace period has already been requested at that node, if the node believes that the future normal RCU grace period as already started, or if the node is not the initial node and believes that any normal RCU grace period is underway. Otherwise, a request for the future normal RCU grace period is recorded at the node.