rcu: Settle config for userspace extended quiescent state

[deliverable/linux.git] / arch / Kconfig

diff --git a/arch/Kconfig b/arch/Kconfig
index 72f2fa189cc5200bb98143c6b35de8ffc9e0aaee..1401a758797316ef402c6a35d5957643931a7f8e 100644 (file)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -281,4 +281,14 @@ config SECCOMP_FILTER
 
          See Documentation/prctl/seccomp_filter.txt for details.
 
+config HAVE_RCU_USER_QS
+       bool
+       help
+         Provide kernel entry/exit hooks necessary for userspace
+         RCU extended quiescent state. Syscalls need to be wrapped inside
+         rcu_user_exit()-rcu_user_enter() through the slow path using
+         TIF_NOHZ flag. Exceptions handlers must be wrapped as well. Irqs
+         are already protected inside rcu_irq_enter/rcu_irq_exit() but
+         preemption or signal handling on irq exit still need to be protected.
+
 source "kernel/gcov/Kconfig"