Re: [GIT PULL] time.c - respin

[Ingo Molnar <mingo@elte.hu>]

* Glauber Costa <gcosta@redhat.com> wrote:

> Ingo, please pull the latest master git tree from:
> 
>    git://git.kernel.org/pub/scm/linux/kernel/git/glommer/linux-2.6-x86-integration.git master
> 
> into your tree. It solves a bisectability issue, but I can't, 
> unfortunately, reproduce the problem you report. So hopefuly you'll 
> now be able to bisect your problems to a point we can find out what's 
> going on

i've tried it, and -tip testing found a hang on 64-bit x86.

It hangs here:

[    0.340029] calling  tc_filter_init+0x0/0x4c
[    0.340029] initcall tc_filter_init+0x0/0x4c returned 0 after 0 msecs
[    0.340029] calling  genl_init+0x0/0xd8
[ hard hang ]

it should have continued with:

[    2.976346] initcall genl_init+0x0/0xd8 returned 0 after 15 msecs
[    2.982303] calling  cipso_v4_init+0x0/0x88
[ ... etc ... ]

i've bisected the hang back to:

0de577d0dd2d1101431d3438d0880fa32a6188d6 is first bad commit
commit 0de577d0dd2d1101431d3438d0880fa32a6188d6
Author: Glauber Costa <gcosta@redhat.com>
Date:   Fri Jul 11 15:43:19 2008 -0300

    x86: use generic intr_init call

    Replace apic initialization code with generic intr_init_hook().

    Signed-off-by: Glauber Costa <gcosta@redhat.com>

the config is at:

 http://redhat.com/~mingo/misc/config-Thu_Aug_21_11_14_36_CEST_2008.bad

but the bug is rather obvious:

-       apic_intr_init();
-
-       if (!acpi_ioapic)
-               setup_irq(2, &irq2);
+       intr_init_hook();

why exactly did you remove the cascade IRQ registration? If it remains 
unallocated and a driver happens to use it funny things might occur.

Also, the commit log does not declare why it's removed.

	Ingo