using RCU rather than SRCU, because RCU is almost always faster
and easier to use than is SRCU.
- If you need to enter your read-side critical section in a
- hardirq or exception handler, and then exit that same read-side
- critical section in the task that was interrupted, then you need
- to srcu_read_lock_raw() and srcu_read_unlock_raw(), which avoid
- the lockdep checking that would otherwise this practice illegal.
-
Also unlike other forms of RCU, explicit initialization
and cleanup is required via init_srcu_struct() and
cleanup_srcu_struct(). These are passed a "struct srcu_struct"