rcu: Print per-CPU callback counts for forward-progress failures (bfcfcffc) · Commits · 戴 / test

This commit prints out the non-zero per-CPU callback counts when a forware-progress error (OOM event) occurs. Signed-off-by:

Paul E. McKenney <paulmck@linux.ibm.com> [ paulmck: Fix a pair of uninitialized locals spotted by kbuild test robot. ]

kernel/rcu/tree.c

+18 −0

Original line number	Diff line number	Diff line
		@@ -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);