Re: overlaping printk

[Ingo Molnar <mingo@elte.hu>]

* Ricky Beam <jfbeam@bluetronic.net> wrote:

> It looks like somewhere in the path of release_console_sem() more than
> one CPU is running the log. [...]

the problem is this code in printk:

        if (oops_in_progress) {
                /* 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);
        }

so two crashes on two separate CPUs can go on in parallel. The problem
is not constrained to the serial line - i've seen it on VGA too (albeit
there it's much more rare).

	Ingo