Re: printk() with a spin-lock held.

[linux-os]

On Mon, 25 Oct 2004, Lee Revell wrote:

> On Mon, 2004-10-25 at 08:32 -0400, Richard B. Johnson wrote:
> > I recall that printk() useds to just write stuff into a buffer,
> > that the buffer (the same buffer used for dmesg), was written
> > out only when it was safe to do so.
> >
> >
> > Now, if printk() can't do that anymore, how does one de-bug
> > ISR code? Or do you just heave it off the cliff and hope that
> > it flies?
>
> No, it can, I was wrong.  I was thinking of some other function.
>
> Lee

Yes. I think that the problem I observed was when the ISR
wouldn't reset the interrupt because the hardware was broken.
This makes the level-interrupt stay active forever. I put
a printk() in the ISR and I got a bug-check because printk
didn't like me.

Apparently, if the printk() buffer gets full, it bug-checks.
The behavior used to be that it would just dump overflow
on the floor.

Cheers,
Dick Johnson
Penguin : Linux version 2.6.9 on an i686 machine (5537.79 GrumpyMips).
                 98.36% of all statistics are fiction.
-
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/