Currently, show_rcu_gp_kthreads() only dumps rcu_node structures that
have outdated ideas of the current grace-period number. This commit
also dumps those that are in any way blocking the current grace period.
This helps diagnose RCU priority boosting failures.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/tree_stall.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index c1f83864a18e..e6bd518e0bc4 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -746,8 +746,9 @@ void show_rcu_gp_kthreads(void)
data_race(rcu_state.gp_max),
data_race(rcu_state.gp_flags));
rcu_for_each_node_breadth_first(rnp) {
- if (ULONG_CMP_GE(READ_ONCE(rcu_state.gp_seq),
- READ_ONCE(rnp->gp_seq_needed)))
+ if (ULONG_CMP_GE(READ_ONCE(rcu_state.gp_seq), READ_ONCE(rnp->gp_seq_needed)) &&
+ !data_race(rnp->qsmask) && !data_race(rnp->boost_tasks) &&
+ !data_race(rnp->exp_tasks) && !data_race(rnp->gp_tasks))
continue;
pr_info("\trcu_node %d:%d ->gp_seq %ld ->gp_seq_needed %ld ->qsmask %#lx %c%c%c%c ->n_boosts %ld\n",
rnp->grplo, rnp->grphi,
--
2.31.1.189.g2e36527f23
