rcu: Permit RCU_FAST_NO_HZ to be used by TREE_PREEMPT_RCU
The new implementation of RCU_FAST_NO_HZ is compatible with preemptible
RCU, so this commit removes the Kconfig restriction that previously
prohibited this.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
diff --git a/init/Kconfig b/init/Kconfig
index 43298f9..82b6a4c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -469,14 +469,14 @@
config RCU_FAST_NO_HZ
bool "Accelerate last non-dyntick-idle CPU's grace periods"
- depends on TREE_RCU && NO_HZ && SMP
+ depends on NO_HZ && SMP
default n
help
This option causes RCU to attempt to accelerate grace periods
- in order to allow the final CPU to enter dynticks-idle state
- more quickly. On the other hand, this option increases the
- overhead of the dynticks-idle checking, particularly on systems
- with large numbers of CPUs.
+ in order to allow CPUs to enter dynticks-idle state more
+ quickly. On the other hand, this option increases the overhead
+ of the dynticks-idle checking, particularly on systems with
+ large numbers of CPUs.
Say Y if energy efficiency is critically important, particularly
if you have relatively few CPUs.