[PATCH 06/11] rcu: clear t->rcu_read_unlock_special in one go

Lai Jiangshan
2019-10-31T10:09:35Z

Clearing t->rcu_read_unlock_special in one go makes the code
more clearly.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
kernel/rcu/tree_plugin.h | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index bb3bcdb5c9b8..e612c77dc446 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -420,6 +420,7 @@ static bool rcu_preempt_has_tasks(struct rcu_node *rnp)
* Report deferred quiescent states. The deferral time can
* be quite short, for example, in the case of the call from
* rcu_read_unlock_special().
+ * t->rcu_read_unlock_special is cleared after called.
*/
static void
rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags)
@@ -439,11 +440,9 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags)
* t->rcu_read_unlock_special cannot change.
*/
special = t->rcu_read_unlock_special;
- t->rcu_read_unlock_special.b.exp_hint = false;
- t->rcu_read_unlock_special.b.deferred_qs = false;
+ t->rcu_read_unlock_special.s = 0;
if (special.b.need_qs) {
rcu_qs();
- t->rcu_read_unlock_special.b.need_qs = false;
}

/*
@@ -459,8 +458,6 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags)

/* Clean up if blocked during RCU read-side critical section. */
if (special.b.blocked) {
- t->rcu_read_unlock_special.b.blocked = false;
-
/*
* Remove this task from the list it blocked on. The task
* now remains queued on the rcu_node corresponding to the
--
2.20.1