[PATCH rcu 2/3] rcu/nocb: Add CPU number to CPU-{,de}offload failure messages

From: Paul E. McKenney
Date: Wed Aug 31 2022 - 14:13:04 EST


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@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/tree_nocb.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index f20aec4f4394b..0a5f0ef414845 100644
--- 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;
}
}
--
2.31.1.189.g2e36527f23