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-rw-r--r--kernel/rcu/Kconfig17
1 files changed, 9 insertions, 8 deletions
diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
index 7644eda17d62..1cc940fef17c 100644
--- a/kernel/rcu/Kconfig
+++ b/kernel/rcu/Kconfig
@@ -7,7 +7,7 @@ menu "RCU Subsystem"
config TREE_RCU
bool
- default y if !PREEMPTION && SMP
+ default y if SMP
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
@@ -17,6 +17,7 @@ config TREE_RCU
config PREEMPT_RCU
bool
default y if PREEMPTION
+ select TREE_RCU
help
This option selects the RCU implementation that is
designed for very large SMP systems with hundreds or
@@ -78,7 +79,7 @@ config TASKS_RCU
user-mode execution as quiescent states.
config RCU_STALL_COMMON
- def_bool ( TREE_RCU || PREEMPT_RCU )
+ def_bool TREE_RCU
help
This option enables RCU CPU stall code that is common between
the TINY and TREE variants of RCU. The purpose is to allow
@@ -86,13 +87,13 @@ config RCU_STALL_COMMON
making these warnings mandatory for the tree variants.
config RCU_NEED_SEGCBLIST
- def_bool ( TREE_RCU || PREEMPT_RCU || TREE_SRCU )
+ def_bool ( TREE_RCU || TREE_SRCU )
config RCU_FANOUT
int "Tree-based hierarchical RCU fanout value"
range 2 64 if 64BIT
range 2 32 if !64BIT
- depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT
+ depends on TREE_RCU && RCU_EXPERT
default 64 if 64BIT
default 32 if !64BIT
help
@@ -112,7 +113,7 @@ config RCU_FANOUT_LEAF
int "Tree-based hierarchical RCU leaf-level fanout value"
range 2 64 if 64BIT
range 2 32 if !64BIT
- depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT
+ depends on TREE_RCU && RCU_EXPERT
default 16
help
This option controls the leaf-level fanout of hierarchical
@@ -187,7 +188,7 @@ config RCU_BOOST_DELAY
config RCU_NOCB_CPU
bool "Offload RCU callback processing from boot-selected CPUs"
- depends on TREE_RCU || PREEMPT_RCU
+ depends on TREE_RCU
depends on RCU_EXPERT || NO_HZ_FULL
default n
help
@@ -200,8 +201,8 @@ config RCU_NOCB_CPU
specified at boot time by the rcu_nocbs parameter. For each
such CPU, a kthread ("rcuox/N") will be created to invoke
callbacks, where the "N" is the CPU being offloaded, and where
- the "p" for RCU-preempt (PREEMPT kernels) and "s" for RCU-sched
- (!PREEMPT kernels). Nothing prevents this kthread from running
+ the "p" for RCU-preempt (PREEMPTION kernels) and "s" for RCU-sched
+ (!PREEMPTION kernels). Nothing prevents this kthread from running
on the specified CPUs, but (1) the kthreads may be preempted
between each callback, and (2) affinity or cgroups can be used
to force the kthreads to run on whatever set of CPUs is desired.