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

[firefly-linux-kernel-4.4.55.git] / init / Kconfig

diff --git a/init/Kconfig b/init/Kconfig
index c9728992a776356e043d21df7b33aa045c2d7904..526ec1c7456a901d896cc3dca7edec19ff242d70 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -393,7 +393,6 @@ config PREEMPT_RCU
 
 config RCU_TRACE
        bool "Enable tracing for 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.
        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.
 
          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
 endmenu # "RCU Subsystem"
 
 config IKCONFIG