rcu: Userspace RCU extended QS selftest

Provide a config option that enables the userspace
RCU extended quiescent state on every CPUs by default.

This is for testing purpose.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/init/Kconfig b/init/Kconfig
index f6a1830165ce..c26b8a1d2b57 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -451,6 +451,14 @@ config RCU_USER_QS
           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