If any CB is queued into the bypass list, then trace_rcu_callback() does
not show it. This makes it not clear when a callback was actually
queued, as you only end up getting a trace_rcu_invoke_callback() trace.
Fix it by moving trace_rcu_callback() before trace_rcu_nocb_try_bypass().
Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 67026382dc21..6e14f0257669 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3101,10 +3101,7 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy)
}
check_cb_ovld(rdp);
- if (rcu_nocb_try_bypass(rdp, head, &was_alldone, flags, lazy))
- return; // Enqueued onto ->nocb_bypass, so just leave.
- // If no-CBs CPU gets here, rcu_nocb_try_bypass() acquired ->nocb_lock.
- rcu_segcblist_enqueue(&rdp->cblist, head);
+
if (__is_kvfree_rcu_offset((unsigned long)func))
trace_rcu_kvfree_callback(rcu_state.name, head,
(unsigned long)func,
@@ -3113,6 +3110,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy)
trace_rcu_callback(rcu_state.name, head,
rcu_segcblist_n_cbs(&rdp->cblist));
+ if (rcu_nocb_try_bypass(rdp, head, &was_alldone, flags, lazy))
+ return; // Enqueued onto ->nocb_bypass, so just leave.
+ // If no-CBs CPU gets here, rcu_nocb_try_bypass() acquired ->nocb_lock.
+ rcu_segcblist_enqueue(&rdp->cblist, head);
+
trace_rcu_segcb_stats(&rdp->cblist, TPS("SegCBQueued"));
/* Go handle any RCU core processing required. */
--
2.37.2.609.g9ff673ca1a-goog
