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-rw-r--r--init/Kconfig55
1 files changed, 54 insertions, 1 deletions
diff --git a/init/Kconfig b/init/Kconfig
index c9728992a776..526ec1c7456a 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -393,7 +393,6 @@ config PREEMPT_RCU
config RCU_TRACE
bool "Enable tracing for RCU"
- depends on TREE_RCU || TREE_PREEMPT_RCU
help
This option provides tracing in RCU which presents stats
in debugfs for debugging RCU implementation.
@@ -459,6 +458,60 @@ config TREE_RCU_TRACE
TREE_PREEMPT_RCU implementations, permitting Makefile to
trivially select kernel/rcutree_trace.c.
+config RCU_BOOST
+ bool "Enable RCU priority boosting"
+ depends on RT_MUTEXES && TINY_PREEMPT_RCU
+ default n
+ help
+ This option boosts the priority of preempted RCU readers that
+ block the current preemptible RCU grace period for too long.
+ This option also prevents heavy loads from blocking RCU
+ callback invocation for all flavors of RCU.
+
+ Say Y here if you are working with real-time apps or heavy loads
+ Say N here if you are unsure.
+
+config RCU_BOOST_PRIO
+ int "Real-time priority to boost RCU readers to"
+ range 1 99
+ depends on RCU_BOOST
+ default 1
+ help
+ This option specifies the real-time priority to which preempted
+ RCU readers are to be boosted. If you are working with CPU-bound
+ real-time applications, you should specify a priority higher then
+ the highest-priority CPU-bound application.
+
+ Specify the real-time priority, or take the default if unsure.
+
+config RCU_BOOST_DELAY
+ int "Milliseconds to delay boosting after RCU grace-period start"
+ range 0 3000
+ depends on RCU_BOOST
+ default 500
+ help
+ This option specifies the time to wait after the beginning of
+ a given grace period before priority-boosting preempted RCU
+ readers blocking that grace period. Note that any RCU reader
+ blocking an expedited RCU grace period is boosted immediately.
+
+ Accept the default if unsure.
+
+config SRCU_SYNCHRONIZE_DELAY
+ int "Microseconds to delay before waiting for readers"
+ range 0 20
+ default 10
+ help
+ This option controls how long SRCU delays before entering its
+ loop waiting on SRCU readers. The purpose of this loop is
+ to avoid the unconditional context-switch penalty that would
+ otherwise be incurred if there was an active SRCU reader,
+ in a manner similar to adaptive locking schemes. This should
+ be set to be a bit longer than the common-case SRCU read-side
+ critical-section overhead.
+
+ Accept the default if unsure.
+
endmenu # "RCU Subsystem"
config IKCONFIG