X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=kernel%2FKconfig.preempt;h=9fdba03dc1fcd119c31274fb3590480aa1db9f05;hb=bf31338bfd5d04434adf2294255847bb7dad687a;hp=61fa116efcdefcc21a6216c9193a75e78eb86864;hpb=e260be673a15b6125068270e0216a3bfbfc12f87;p=firefly-linux-kernel-4.4.55.git

diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 61fa116efcde..9fdba03dc1fc 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -52,19 +52,23 @@ config PREEMPT
 
 endchoice
 
-config PREEMPT_BKL
-	bool "Preempt The Big Kernel Lock"
-	depends on SMP || PREEMPT
-	default y
+config PREEMPT_RCU
+	bool "Preemptible RCU"
+	depends on PREEMPT
+	default n
 	help
-	  This option reduces the latency of the kernel by making the
-	  big kernel lock preemptible.
+	  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 Y here if you are building a kernel for a desktop system.
 	  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