[PATCH tip/core/rcu 1/9] rcu: Permit RCU_FAST_NO_HZ to be used by TREE_PREEMPT_RCU

From: Paul E. McKenney
Date: Tue Nov 15 2011 - 15:28:17 EST


From: Paul E. McKenney <paul.mckenney@xxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxx>
---
init/Kconfig | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index 43298f9..82b6a4c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -469,14 +469,14 @@ config RCU_FANOUT_EXACT

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.
--
1.7.3.2

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