Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next

Pull RCU changes from Ingo Molnar:
 "The main RCU changes in this cycle were:

   - RCU torture-test changes.

   - variable-name renaming cleanup.

   - update RCU documentation.

   - miscellaneous fixes.

   - patch to suppress RCU stall warnings while sysrq requests are being
     processed"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (68 commits)
  rcu: Provide API to suppress stall warnings while sysrc runs
  rcu: Variable name changed in tree_plugin.h and used in tree.c
  torture: Remove unused definition
  torture: Remove __init from torture_init_begin/end
  torture: Check for multiple concurrent torture tests
  locktorture: Remove reference to nonexistent Kconfig parameter
  rcutorture: Run rcu_torture_writer at normal priority
  rcutorture: Note diffs from git commits
  rcutorture: Add missing destroy_timer_on_stack()
  rcutorture: Explicitly test synchronous grace-period primitives
  rcutorture:  Add tests for get_state_synchronize_rcu()
  rcutorture: Test RCU-sched primitives in TREE_PREEMPT_RCU kernels
  torture: Use elapsed time to detect hangs
  rcutorture: Check for rcu_torture_fqs creation errors
  torture: Better summary diagnostics for build failures
  torture: Notice if an all-zero cpumask is passed inside a critical section
  rcutorture: Make rcu_torture_reader() use cond_resched()
  sched,rcu: Make cond_resched() report RCU quiescent states
  percpu: Fix raw_cpu_inc_return()
  rcutorture: Export RCU grace-period kthread wait state to rcutorture
  ...

1 files changed, 6 insertions, 1 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0a7251678982..71d9a9c93954 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4084,6 +4084,7 @@ static void __cond_resched(void)
 
 int __sched _cond_resched(void)
 {
+	rcu_cond_resched();
 	if (should_resched()) {
 		__cond_resched();
 		return 1;
@@ -4102,15 +4103,18 @@ EXPORT_SYMBOL(_cond_resched);
  */
 int __cond_resched_lock(spinlock_t *lock)
 {
+	bool need_rcu_resched = rcu_should_resched();
 	int resched = should_resched();
 	int ret = 0;
 
 	lockdep_assert_held(lock);
 
-	if (spin_needbreak(lock) || resched) {
+	if (spin_needbreak(lock) || resched || need_rcu_resched) {
 		spin_unlock(lock);
 		if (resched)
 			__cond_resched();
+		else if (unlikely(need_rcu_resched))
+			rcu_resched();
 		else
 			cpu_relax();
 		ret = 1;
@@ -4124,6 +4128,7 @@ int __sched __cond_resched_softirq(void)
 {
 	BUG_ON(!in_softirq());
 
+	rcu_cond_resched();  /* BH disabled OK, just recording QSes. */
 	if (should_resched()) {
 		local_bh_enable();
 		__cond_resched();