Re: 2.6.29-rc1 does not boot

Ingo Molnar
2009-01-11T19:03:08Z

* Dieter Ries <clip2@gmx.de> wrote:

> Bisected it:
>
> ####################################################################
> 7503bfbae89eba07b46441a5d1594647f6b8ab7d is first bad commit
> commit 7503bfbae89eba07b46441a5d1594647f6b8ab7d
> Author: Mike Travis <travis@sgi.com>
> Date: Sun Jan 4 05:18:09 2009 -0800
>
> cpumask: use work_on_cpu in acpi-cpufreq.c for drv_read and drv_write
>
> Impact: use new cpumask API to reduce stack usage

thanks, this is very helpful!

Mike, most of the work_on_cpu() patches you did so far were rather
problematic. Especially something like cpufreq can run rather early during
bootup or during suspend/resume, so i'm not sure it's correct to rely on
keventd for it.

I dont see anything particularly wrong in the commit itself - but
obviously it causes this boot hang - if the bug is not found we'll revert
it .

Also, this bit in get_cur_val():

+ if (unlikely(!alloc_cpumask_var(&cmd.mask, GFP_KERNEL)))
+ return 0;

how is that supposed to work? If we fail to allocate a cpumask we just
ignore the call silently? That cannot be right. (but has no connection to
this boot problem)

Ingo