diff options
Diffstat (limited to 'lib/dump_stack.c')
| -rw-r--r-- | lib/dump_stack.c | 38 |
1 files changed, 2 insertions, 36 deletions
diff --git a/lib/dump_stack.c b/lib/dump_stack.c index f5a33b6f773f..5ebf4375fa8c 100644 --- a/lib/dump_stack.c +++ b/lib/dump_stack.c @@ -84,50 +84,16 @@ static void __dump_stack(void) * * Architectures can override this implementation by implementing its own. */ -#ifdef CONFIG_SMP -static atomic_t dump_lock = ATOMIC_INIT(-1); - asmlinkage __visible void dump_stack(void) { unsigned long flags; - int was_locked; - int old; - int cpu; /* * Permit this cpu to perform nested stack dumps while serialising * against other CPUs */ -retry: - local_irq_save(flags); - cpu = smp_processor_id(); - old = atomic_cmpxchg(&dump_lock, -1, cpu); - if (old == -1) { - was_locked = 0; - } else if (old == cpu) { - was_locked = 1; - } else { - local_irq_restore(flags); - /* - * Wait for the lock to release before jumping to - * atomic_cmpxchg() in order to mitigate the thundering herd - * problem. - */ - do { cpu_relax(); } while (atomic_read(&dump_lock) != -1); - goto retry; - } - - __dump_stack(); - - if (!was_locked) - atomic_set(&dump_lock, -1); - - local_irq_restore(flags); -} -#else -asmlinkage __visible void dump_stack(void) -{ + printk_cpu_lock_irqsave(flags); __dump_stack(); + printk_cpu_unlock_irqrestore(flags); } -#endif EXPORT_SYMBOL(dump_stack); |