* Ingo Molnar <mingo@xxxxxxx> wrote:
> So some essential piece of the puzzle is still missing.
Oh. I think the essential piece of the puzzle might be this code in
printk():
asmlinkage int vprintk(const char *fmt, va_list args)
{
...
lockdep_off();
if (console_trylock_for_printk(this_cpu))
console_unlock();
lockdep_on();
...
So while i right now do not see how this (ancient) piece of logic
causes trouble, could you try the patch below, does it make the
WARN()+lockup go away?
Thanks,
Ingo
diff --git a/kernel/printk.c b/kernel/printk.c
index 3518539..1b9d2be 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -859,7 +859,6 @@ asmlinkage int vprintk(const char *fmt, va_list args)
zap_locks();
}
- lockdep_off();
spin_lock(&logbuf_lock);
printk_cpu = this_cpu;
@@ -947,7 +946,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
* Try to acquire and then immediately release the
* console semaphore. The release will do all the
* actual magic (print out buffers, wake up klogd,
- * etc).
+ * etc).
*
* The console_trylock_for_printk() function
* will release 'logbuf_lock' regardless of whether it
@@ -956,7 +955,6 @@ asmlinkage int vprintk(const char *fmt, va_list args)
if (console_trylock_for_printk(this_cpu))
console_unlock();
- lockdep_on();
out_restore_irqs:
raw_local_irq_restore(flags);
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|