Re: printk() vs tty_io

From: Peter Zijlstra
Date: Wed Dec 14 2011 - 04:44:10 EST


On Wed, 2011-12-14 at 07:59 +0100, Ingo Molnar wrote:

> btw., would be nice to also somehow realeasify those debug hacks
> to preserve them for eternity - doing all lockdep output as
> earlyprintk while keeping printks working is a great way to
> debug printk() itself.
>
> Those printk lockups also took a *lot* of time for me to bisect.

Yeah, they're horrible.. took me long enough to reproduce, and even now
I know how its not easy.

Anyway, I just posted the two patches that make lockdep do
early_printk(), they're not too horrid. I still need to look at making
dump_stack() play nice as well, but so far I've managed to grok bits
from the held lock output only.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/