rcu: Print per-CPU callback counts for forward-progress failures

[platform/kernel/linux-starfive.git] / kernel / rcu / tree.c

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 0933d86..90a67c7 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2675,6 +2675,10 @@ rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp,
  */
 void rcu_fwd_progress_check(unsigned long j)
 {
+       unsigned long cbs;
+       int cpu;
+       unsigned long max_cbs = 0;
+       int max_cpu = -1;
        struct rcu_data *rdp;
 
        if (rcu_gp_in_progress()) {
@@ -2685,6 +2689,20 @@ void rcu_fwd_progress_check(unsigned long j)
                rcu_check_gp_start_stall(rdp->mynode, rdp, j);
                preempt_enable();
        }
+       for_each_possible_cpu(cpu) {
+               cbs = rcu_get_n_cbs_cpu(cpu);
+               if (!cbs)
+                       continue;
+               if (max_cpu < 0)
+                       pr_info("%s: callbacks", __func__);
+               pr_cont(" %d: %lu", cpu, cbs);
+               if (cbs <= max_cbs)
+                       continue;
+               max_cbs = cbs;
+               max_cpu = cpu;
+       }
+       if (max_cpu >= 0)
+               pr_cont("\n");
 }
 EXPORT_SYMBOL_GPL(rcu_fwd_progress_check);