Re: soft lockup in serial8250_console_write(?)

From: Randy.Dunlap
Date: Tue Mar 14 2006 - 18:13:39 EST


On Tue, 14 Mar 2006 22:40:49 +0100 Ingo Molnar wrote:

>
> * Randy.Dunlap <rdunlap@xxxxxxxxxxxx> wrote:
>
> > Hi,
> >
> > (x86_64; 2.6.16-rc6; serial console configured but nothing connected
> > to the serial port)
> >
> > I'm seeing an occasional soft lockup, maybe in
> > serial8250_console_write(). (drivers/serial/8250.c)
> >
> > This function calls wait_for_xmitr() [inline], which in worst case can
> > spin for 1.010 seconds. Could this be the cause of a soft lockup?
>
> hm, it shouldnt cause that. Could you try the attached patch [which is
> the next-gen softlockup detector], do you get the message even with that
> one applied?

5/5 good boots with your new patch.
5/5 soft lockups without it.

Is this scheduled for post-2.6.16 ?

Thanks,
---
~Randy
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