Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck...

[pandora-kernel.git] / init / Kconfig

diff --git a/init/Kconfig b/init/Kconfig
index c972899..526ec1c 100644 (file)
--- 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