rcu/nocb: Add CPU number to CPU-{,de}offload failure messages

Offline CPUs cannot be offloaded or deoffloaded.  Any attempt to offload
or deoffload an offline CPU causes a message to be printed on the console,
which is good, but this message does not contain the CPU number, which
is bad.  Such a CPU number can be helpful when debugging, as it gives a
clear indication that the CPU in question is in fact offline.  This commit
therefore adds the CPU number to the CPU-{,de}offload failure messages.

Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index f20aec4..0a5f0ef 100644 (file)
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -1111,7 +1111,7 @@ int rcu_nocb_cpu_deoffload(int cpu)
                        if (!ret)
                                cpumask_clear_cpu(cpu, rcu_nocb_mask);
                } else {
-                       pr_info("NOCB: Can't CB-deoffload an offline CPU\n");
+                       pr_info("NOCB: Cannot CB-deoffload offline CPU %d\n", rdp->cpu);
                        ret = -EINVAL;
                }
        }
@@ -1196,7 +1196,7 @@ int rcu_nocb_cpu_offload(int cpu)
                        if (!ret)
                                cpumask_set_cpu(cpu, rcu_nocb_mask);
                } else {
-                       pr_info("NOCB: Can't CB-offload an offline CPU\n");
+                       pr_info("NOCB: Cannot CB-offload offline CPU %d\n", rdp->cpu);
                        ret = -EINVAL;
                }
        }