System and method for implementing NUMA-aware reader-writer locks

摘要

NUMA-aware reader-writer locks may leverage lock cohorting techniques to band together writer requests from a single NUMA node. The locks may relax the order in which the lock schedules the execution of critical sections of code by reader threads and writer threads, allowing lock ownership to remain resident on a single NUMA node for long periods, while also taking advantage of parallelism between reader threads. Threads may contend on node-level structures to get permission to acquire a globally shared reader-writer lock. Writer threads may follow a lock cohorting strategy of passing ownership of the lock in write mode from one thread to a cohort writer thread without releasing the shared lock, while reader threads from multiple NUMA nodes may simultaneously acquire the shared lock in read mode. The reader-writer lock may follow a writer-preference policy, a reader-preference policy or a hybrid policy.