D.4.2.2.6 rcu_mb_flag

The rcu_mb_flag per-CPU variable alerts the corresponding CPU that it must execute a memory barrier in order for the grace-period state machine to proceed, and also records that CPU's acknowledgment. Once a given CPU has executed its memory barrier, the memory operations of all prior RCU read-side critical will be visible to any code sequenced after the corresponding grace period.



Paul E. McKenney 2011-12-16