In Realtime RCU [GMTW08] (see
Section ),
SRCU [McK06] (see
Section
, or
QRCU [McK07f] (see
Section
,
each of which is described in
the final installment of this series,
a preempted reader will prevent
a grace period from completing, even if a high-priority task is
blocked waiting for that grace period to complete.
Realtime RCU can avoid this problem by substituting call_rcu()
for synchronize_rcu() or by using RCU priority
boosting [McK07d,GMTW08],
which is still in experimental status as of early 2008.
It might become necessary to augment SRCU and QRCU with priority boosting,
but not before a clear real-world need is demonstrated.