Re: Strange hang on ia64 with CONFIG_PRINTK_TIME=y

From: Ingo Molnar
Date: Wed Feb 20 2008 - 03:12:51 EST



* 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?

Ingo
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