printk: Make console_sem a semaphore not a pseudo mutex
Thomas Gleixner [Tue, 7 Sep 2010 14:33:43 +0000 (14:33 +0000)]
It needs to be investigated whether it can be replaced by a real
mutex, but that needs more thought.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
LKML-Reference: <20100907125057.179587334@linutronix.de>

kernel/printk.c

index 8fe465a..2531017 100644 (file)
@@ -85,7 +85,7 @@ EXPORT_SYMBOL(oops_in_progress);
  * provides serialisation for access to the entire console
  * driver system.
  */
-static DECLARE_MUTEX(console_sem);
+static DEFINE_SEMAPHORE(console_sem);
 struct console *console_drivers;
 EXPORT_SYMBOL_GPL(console_drivers);
 
@@ -556,7 +556,7 @@ static void zap_locks(void)
        /* If a crash is occurring, make sure we can't deadlock */
        spin_lock_init(&logbuf_lock);
        /* And make sure that we print immediately */
-       init_MUTEX(&console_sem);
+       sema_init(&console_sem, 1);
 }
 
 #if defined(CONFIG_PRINTK_TIME)