rcu: move PREEMPT_RCU config option back under PREEMPT

[sfrench/cifs-2.6.git] / init / Kconfig

diff --git a/init/Kconfig b/init/Kconfig
index 074ac97f55e32a505ea3479ba85d0c3c619ac9e6..a97924bc5b8dcfa87079ee2f9f70ce9988d4bf40 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -865,38 +865,10 @@ source "block/Kconfig"
 config PREEMPT_NOTIFIERS
        bool
 
-choice
-       prompt "RCU implementation type:"
-       default CLASSIC_RCU
-       help
-         This allows you to choose either the classic RCU implementation
-         that is designed for best read-side performance on non-realtime
-         systems, or the preemptible RCU implementation for best latency
-         on realtime systems.  Note that some kernel preemption modes
-         will restrict your choice.
-
-         Select the default if you are unsure.
-
 config CLASSIC_RCU
-       bool "Classic RCU"
+       def_bool !PREEMPT_RCU
        help
          This option selects the classic RCU implementation that is
          designed for best read-side performance on non-realtime
-         systems.
-
-         Say Y if you are unsure.
-
-config PREEMPT_RCU
-       bool "Preemptible RCU"
-       depends on PREEMPT
-       help
-         This option reduces the latency of the kernel by making certain
-         RCU sections preemptible. Normally RCU code is non-preemptible, if
-         this option is selected then read-only RCU sections become
-         preemptible. This helps latency, but may expose bugs due to
-         now-naive assumptions about each RCU read-side critical section
-         remaining on a given CPU through its execution.
-
-         Say N if you are unsure.
-
-endchoice
+         systems.  Classic RCU is the default.  Note that the
+         PREEMPT_RCU symbol is used to select/deselect this option.