Embodiments of the invention provide a method of creating, based on an operating-system-scheduled thread running on an operating-system-visible sequencer and using an instruction set extension, a persistent user-level thread to run on an operating-system-sequestered sequencer independently of context switch activities on the operating-system-scheduled thread. The operating-system-scheduled thread and the persistent user-level thread may share a common virtual address space. Embodiments of the invention may also provide a method of causing a service thread running on an additional operating-system-visible sequencer to provide operating system services to the persistent user-level thread. Embodiments of the invention may further provide apparatus, system, and machine-readable medium thereof.