synchronize_srcu_expedited — Brute-force SRCU grace period
| void synchronize_srcu_expedited ( | struct srcu_struct * sp ); | 
Wait for an SRCU grace period to elapse, but be more aggressive about spinning rather than blocking when waiting.
   Note that synchronize_srcu_expedited has the same deadlock and
   memory-ordering properties as does synchronize_srcu.