Re: Strange hang on ia64 with CONFIG_PRINTK_TIME=y

From: David Miller
Date: Wed Feb 20 2008 - 03:14:57 EST


From: Ingo Molnar <mingo@xxxxxxx>
Date: Wed, 20 Feb 2008 09:12:28 +0100

>
> * Tony Luck <tony.luck@xxxxxxxxx> wrote:
>
> > > Perhaps what is happening is that cpu0 comes online ... safely skips
> > > over the early printk calls. Calls cpu_init() which sets up the
> > > resources *it* needs (ar.k3 points to per-cpu space), and then
> > > executes sched_init() which marks it safe for all printk's. Then
> > > cpu1 comes up and does a printk before it gets to cpu_init().
> >
> > I just tried Ingo's patch[1] on a 2.6.25-rc2 kernel with printk
> > timestamps turned on ... and it booted just fine on my tiger4. The
> > default path for non-boot cpus is from head.S to start_secondary(),
> > and that calls cpu_init() pretty quickly. There shouldn't normally[2]
> > be any printk() calls on the non-boot cpu before it is safe to do so.
>
> ok. I've queued up the patch again in sched.git, as a .25 fix. Can i add
> your Tested-by and Acked-by tags?

Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
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