rcu: Switch task's syscall hooks on context switch

[firefly-linux-kernel-4.4.55.git] / kernel / rcutree.c

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 6b82a956514940a3a4da17338b8c5bb02d2176fb..d2e74c8d4b0e5330d1f4f422cf876041f70688bb 100644 (file)
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -717,6 +717,21 @@ int rcu_is_cpu_idle(void)
 }
 EXPORT_SYMBOL(rcu_is_cpu_idle);
 
+#ifdef CONFIG_RCU_USER_QS
+void rcu_user_hooks_switch(struct task_struct *prev,
+                          struct task_struct *next)
+{
+       struct rcu_dynticks *rdtp;
+
+       /* Interrupts are disabled in context switch */
+       rdtp = &__get_cpu_var(rcu_dynticks);
+       if (!rdtp->ignore_user_qs) {
+               clear_tsk_thread_flag(prev, TIF_NOHZ);
+               set_tsk_thread_flag(next, TIF_NOHZ);
+       }
+}
+#endif /* #ifdef CONFIG_RCU_USER_QS */
+
 #if defined(CONFIG_PROVE_RCU) && defined(CONFIG_HOTPLUG_CPU)
 
 /*