Currently, the rnp's cbovlmask is set in call_rcu(). when CPU going
offline, the outgoing CPU's callbacks is migrated to target CPU, the
number of callbacks on the my_rdp may be overloaded, if overload and
there is no call_rcu() call on target CPU for a long time, the rnp's
cbovldmask is not set in time. in order to fix this situation, add
check_cb_ovld_locked() in rcutree_migrate_callbacks() to help CPU more
quickly reach quiescent states.
Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx>
---
kernel/rcu/tree.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9dc4c4e82db6..bcc5876c9753 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4577,6 +4577,7 @@ void rcutree_migrate_callbacks(int cpu)
needwake = needwake || rcu_advance_cbs(my_rnp, my_rdp);
rcu_segcblist_disable(&rdp->cblist);
WARN_ON_ONCE(rcu_segcblist_empty(&my_rdp->cblist) != !rcu_segcblist_n_cbs(&my_rdp->cblist));
+ check_cb_ovld_locked(my_rdp, my_rnp);
if (rcu_rdp_is_offloaded(my_rdp)) {
raw_spin_unlock_rcu_node(my_rnp); /* irqs remain disabled. */
__call_rcu_nocb_wake(my_rdp, true, flags);
--
2.25.1
