---

yaml --- r: 87095 b: refs/heads/master c: 21bbb39 h: refs/heads/master i: 87093: 7c8679e 87091: 06e7eb1 87087: f49b2b3 v: v3
git-mirror · Mar 11, 2008 · 58db9cf · 58db9cf
1 parent 2ce1c68
commit 58db9cf
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Showing 3 changed files with 19 additions and 32 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f47831fabaf0206abc56ee5a33fd006fe29b6dc6
+refs/heads/master: 21bbb39c376ce6beeeb549d155f0d53dc76ed000
diff --git a/trunk/init/Kconfig b/trunk/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.
diff --git a/trunk/kernel/Kconfig.preempt b/trunk/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