1 files changed, 16 insertions, 6 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 25373cf32672..f88da2d1c1fb 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -335,11 +335,20 @@ config PREEMPT_RCU
           now-naive assumptions about each RCU read-side critical section
           remaining on a given CPU through its execution.
 
+config TREE_PREEMPT_RCU
+        bool "Preemptable tree-based hierarchical RCU"
+        depends on PREEMPT
+        help
+          This option selects the RCU implementation that is
+          designed for very large SMP systems with hundreds or
+          thousands of CPUs, but for which real-time response
+          is also required.
+
 endchoice
 
 config RCU_TRACE
         bool "Enable tracing for RCU"
-        depends on TREE_RCU || PREEMPT_RCU
+        depends on TREE_RCU || PREEMPT_RCU || TREE_PREEMPT_RCU
         help
           This option provides tracing in RCU which presents stats
           in debugfs for debugging RCU implementation.
@@ -351,7 +360,7 @@ config RCU_FANOUT
         int "Tree-based hierarchical RCU fanout value"
         range 2 64 if 64BIT
         range 2 32 if !64BIT
-        depends on TREE_RCU
+        depends on TREE_RCU || TREE_PREEMPT_RCU
         default 64 if 64BIT
         default 32 if !64BIT
         help
@@ -366,7 +375,7 @@ config RCU_FANOUT
 
 config RCU_FANOUT_EXACT
         bool "Disable tree-based hierarchical RCU auto-balancing"
-        depends on TREE_RCU
+        depends on TREE_RCU || TREE_PREEMPT_RCU
         default n
         help
           This option forces use of the exact RCU_FANOUT value specified,
@@ -379,11 +388,12 @@ config RCU_FANOUT_EXACT
           Say N if unsure.
 
 config TREE_RCU_TRACE
-        def_bool RCU_TRACE && TREE_RCU
+        def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
         select DEBUG_FS
         help
-          This option provides tracing for the TREE_RCU implementation,
-          permitting Makefile to trivially select kernel/rcutree_trace.c.
+          This option provides tracing for the TREE_RCU and
+          TREE_PREEMPT_RCU implementations, permitting Makefile to
+          trivially select kernel/rcutree_trace.c.
 
 config PREEMPT_RCU_TRACE
         def_bool RCU_TRACE && PREEMPT_RCU