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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-01-30 17:46:32 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-02-21 18:06:06 +0100 |
| commit | c5fdcec927ee31fc96e92339c3a83ac6e0725289 (patch) | |
| tree | 65511a65eb71990d51b46c7a88a35d51f0662e58 | |
| parent | rcu: No interrupt disabling for rcu_prepare_for_idle() (diff) | |
| download | linux-c5fdcec927ee31fc96e92339c3a83ac6e0725289.tar.xz linux-c5fdcec927ee31fc96e92339c3a83ac6e0725289.zip | |
lockdep: Add CPU-idle/offline warning to lockdep-RCU splat
It is illegal to use RCU from a CPU that has reported idleness or
offlinedness to RCU. However, it can be quite difficult to determine
from a stack trace whether or not a given CPU is idle or offline.
Therefore, this commit adds idle/offline diagnostics to the lockdep-RCU
error message.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | kernel/lockdep.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 8889f7dd7c46..ea9ee4518c35 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -4176,7 +4176,13 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) printk("-------------------------------\n"); printk("%s:%d %s!\n", file, line, s); printk("\nother info that might help us debug this:\n\n"); - printk("\nrcu_scheduler_active = %d, debug_locks = %d\n", rcu_scheduler_active, debug_locks); + printk("\n%srcu_scheduler_active = %d, debug_locks = %d\n", + !rcu_lockdep_current_cpu_online() + ? "RCU used illegally from offline CPU!\n" + : rcu_is_cpu_idle() + ? "RCU used illegally from idle CPU!\n" + : "", + rcu_scheduler_active, debug_locks); /* * If a CPU is in the RCU-free window in idle (ie: in the section |