Expediting RCU grace periods under user mode control

摘要

A technique for supporting user mode specification of Read-Copy Update (RCU) grace period latency to an operating system kernel-level RCU implementation. Non-expedited and expedited RCU grace period mechanisms are provided for invocation by RCU updaters performing RCU update operations to respectively initiate non-expedited and expedited grace periods. An expedited grace period indicator in a kernel memory space is provided for indicating whether a non-expedited RCU grace period or an expedited RCU grace period should be invoked. The non-expedited RCU grace period mechanism is adapted to check the expedited grace period indicator, and if an expedited RCU grace period is indicated, to invoke the expedited grace period mechanism. A communication mechanism is provided for use by a user mode application executing in a user memory space to manipulate the expedited grace period indicator in the kernel memory space, and thereby control whether an expedited or non-expedited RCU grace period should be used.