rcu: Add RCU-sched flavors of get-state and cond-sync
The get_state_synchronize_rcu() and cond_synchronize_rcu() functions
allow polling for grace-period completion, with an actual wait for a
grace period occurring only when cond_synchronize_rcu() is called too
soon after the corresponding get_state_synchronize_rcu(). However,
these functions work only for vanilla RCU. This commit adds the
get_state_synchronize_sched() and cond_synchronize_sched(), which provide
the same capability for RCU-sched.
Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 3df6c1e..ff968b7 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -37,6 +37,16 @@
might_sleep();
}
+static inline unsigned long get_state_synchronize_sched(void)
+{
+ return 0;
+}
+
+static inline void cond_synchronize_sched(unsigned long oldstate)
+{
+ might_sleep();
+}
+
static inline void rcu_barrier_bh(void)
{
wait_rcu_gp(call_rcu_bh);
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 4568791..5abec82 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -76,6 +76,8 @@
void rcu_barrier_sched(void);
unsigned long get_state_synchronize_rcu(void);
void cond_synchronize_rcu(unsigned long oldstate);
+unsigned long get_state_synchronize_sched(void);
+void cond_synchronize_sched(unsigned long oldstate);
extern unsigned long rcutorture_testseq;
extern unsigned long rcutorture_vernum;