Merge branch 'linux-2.6'

1 files changed, 15 insertions, 0 deletions

diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 0669b70fa6a3..9fdba03dc1fc 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -52,8 +52,23 @@ config PREEMPT
 
 endchoice
 
+config PREEMPT_RCU
+        bool "Preemptible RCU"
+        depends on PREEMPT
+        default n
+        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.
+
 config RCU_TRACE
         bool "Enable tracing for RCU - currently stats in debugfs"
+        depends on PREEMPT_RCU
         select DEBUG_FS
         default y
         help