[PATCH] rcu: Remove duplicate RCU exp QS report from rcu_report_dead()

From: Zqiang
Date: Tue Aug 30 2022 - 04:25:55 EST


For PREEMPT_RCU, the rcu_report_dead() is invoked means that the
outgoing CPU mask is clear from leaf rcu_node and has no further
need of RCU, so invoke rcu_preempt_depth() return value is always
zero in rcu_report_dead(), if the current outgoing CPU rcu_data
structure's cpu_no_qs.b.exp is true, the rcu_preempt_deferred_qs()
will invoke rcu_report_exp_rdp() to report exp QS.

for non-PREEMPT_RCU, the rcu_preempt_deferred_qs() is equivalent to
rcu_report_exp_rdp().

Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx>
---
kernel/rcu/tree.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 6bb8e72bc815..0ca21ac0f064 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4276,8 +4276,6 @@ void rcu_report_dead(unsigned int cpu)
// Do any dangling deferred wakeups.
do_nocb_deferred_wakeup(rdp);

- /* QS for any half-done expedited grace period. */
- rcu_report_exp_rdp(rdp);
rcu_preempt_deferred_qs(current);

/* Remove outgoing CPU from mask in the leaf rcu_node structure. */
--
2.25.1