[PATCH tip/core/rcu 18/24] rcu: Create RCU_EXPERT Kconfig and hide booleans behind it

From: Paul E. McKenney
Date: Tue May 12 2015 - 18:34:01 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>

This commit creates an RCU_EXPERT Kconfig and hides the independent
boolean RCU-related user-visible Kconfig parameters behind it, namely
RCU_FAST_NO_HZ and RCU_BOOST. This prevents Kconfig from asking about
these parameters unless the user really wants to be asked.

Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Pranith Kumar <bobby.prani@xxxxxxxxx>
---
init/Kconfig | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index 0ec82362cfc0..7eb4c7b3543c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -501,6 +501,21 @@ config TINY_RCU

endchoice

+config RCU_EXPERT
+ bool "Make expert-level adjustments to RCU configuration"
+ default n
+ help
+ This option needs to be enabled if you wish to make
+ expert-level adjustments to RCU configuration. By default,
+ no such adjustments can be made, which has the often-beneficial
+ side-effect of preventing "make oldconfig" from asking you all
+ sorts of detailed questions about how you would like numerous
+ obscure RCU options to be set up.
+
+ Say Y if you need to make expert-level adjustments to RCU.
+
+ Say N if you are unsure.
+
config SRCU
bool
help
@@ -613,7 +628,7 @@ config RCU_FANOUT_LEAF

config RCU_FAST_NO_HZ
bool "Accelerate last non-dyntick-idle CPU's grace periods"
- depends on NO_HZ_COMMON && SMP
+ depends on NO_HZ_COMMON && SMP && RCU_EXPERT
default n
help
This option permits CPUs to enter dynticks-idle state even if
@@ -639,7 +654,7 @@ config TREE_RCU_TRACE

config RCU_BOOST
bool "Enable RCU priority boosting"
- depends on RT_MUTEXES && PREEMPT_RCU
+ depends on RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT
default n
help
This option boosts the priority of preempted RCU readers that
--
1.8.1.5

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