1 files changed, 18 insertions, 0 deletions

diff --git a/init/Kconfig b/init/Kconfig
index af6c7f8ba019..c26b8a1d2b57 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -441,6 +441,24 @@ config PREEMPT_RCU
           This option enables preemptible-RCU code that is common between
           the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
 
+config RCU_USER_QS
+        bool "Consider userspace as in RCU extended quiescent state"
+        depends on HAVE_RCU_USER_QS && SMP
+        help
+          This option sets hooks on kernel / userspace boundaries and
+          puts RCU in extended quiescent state when the CPU runs in
+          userspace. It means that when a CPU runs in userspace, it is
+          excluded from the global RCU state machine and thus doesn't
+          to keep the timer tick on for RCU.
+
+config RCU_USER_QS_FORCE
+        bool "Force userspace extended QS by default"
+        depends on RCU_USER_QS
+        help
+          Set the hooks in user/kernel boundaries by default in order to
+          test this feature that treats userspace as an extended quiescent
+          state until we have a real user like a full adaptive nohz option.
+
 config RCU_FANOUT
         int "Tree-based hierarchical RCU fanout value"
         range 2 64 if 64BIT