A technique for using expedited RCU grace periods to avoid avoiding out-of-memory conditions for offloaded RCU callbacks. In an example embodiment, one or more processors in a computer system may be designated as no-callbacks (No-CBs) processors that do not perform read-copy update (RCU) callback processing. One or more RCU callback offload kernel threads (rcuo kthreads) may be spawned to perform RCU callback management for RCU callbacks generated by workloads running on the No-CBs processors. The rcuo kthreads may run on processors that are not No-CBs processors. The rcuo kthreads may perform RCU grace period waiting as part of their RCU callback management. The RCU grace period waiting may include selectively invoking either an RCU expedited grace period or waiting for a normal RCU grace period to elapse.