--- zzzz-none-000/linux-3.10.107/Documentation/RCU/rcu.txt 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/Documentation/RCU/rcu.txt 2021-02-04 17:41:59.000000000 +0000 @@ -36,7 +36,7 @@ executed in user mode, or executed in the idle loop, we can safely free up that item. - Preemptible variants of RCU (CONFIG_TREE_PREEMPT_RCU) get the + Preemptible variants of RCU (CONFIG_PREEMPT_RCU) get the same effect, but require that the readers manipulate CPU-local counters. These counters allow limited types of blocking within RCU read-side critical sections. SRCU also uses CPU-local @@ -81,7 +81,7 @@ o I hear that RCU needs work in order to support realtime kernels? This work is largely completed. Realtime-friendly RCU can be - enabled via the CONFIG_TREE_PREEMPT_RCU kernel configuration + enabled via the CONFIG_PREEMPT_RCU kernel configuration parameter. However, work is in progress for enabling priority boosting of preempted RCU read-side critical sections. This is needed if you have CPU-bound realtime threads.