[PATCH tip/core/rcu 19/27] rcu: Add diagnostics for rcutorture writer stall warning

Paul E. McKenney
2018-06-26T00:38:46Z

This commit adds any in-the-future ->gp_seq_needed fields to the
diagnostics for an rcutorture writer stall warning message.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index c5fec335bc31..bc1ed77a3df9 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -606,11 +606,32 @@ EXPORT_SYMBOL_GPL(rcu_sched_force_quiescent_state);
*/
void show_rcu_gp_kthreads(void)
{
+ int cpu;
+ struct rcu_data *rdp;
+ struct rcu_node *rnp;
struct rcu_state *rsp;

for_each_rcu_flavor(rsp) {
pr_info("%s: wait state: %d ->state: %#lx\n",
rsp->name, rsp->gp_state, rsp->gp_kthread->state);
+ rcu_for_each_node_breadth_first(rsp, rnp) {
+ if (ULONG_CMP_GE(rsp->gp_seq, rnp->gp_seq_needed))
+ continue;
+ pr_info("\trcu_node %d:%d ->gp_seq %lu ->gp_seq_needed %lu\n",
+ rnp->grplo, rnp->grphi, rnp->gp_seq,
+ rnp->gp_seq_needed);
+ if (!rcu_is_leaf_node(rnp))
+ continue;
+ for_each_leaf_node_possible_cpu(rnp, cpu) {
+ rdp = per_cpu_ptr(rsp->rda, cpu);
+ if (rdp->gpwrap ||
+ ULONG_CMP_GE(rsp->gp_seq,
+ rdp->gp_seq_needed))
+ continue;
+ pr_info("\tcpu %d ->gp_seq_needed %lu\n",
+ cpu, rdp->gp_seq_needed);
+ }
+ }
/* sched_show_task(rsp->gp_kthread); */
}
}
--
2.17.1