Re: [bisected] 2.6.31 regression: fails to boot as xen guest

[Arnd Hannemann <hannemann@nets.rwth-aachen.de>]

Hi Pekka,

Pekka Enberg wrote:
> On Tue, 2009-08-25 at 18:49 +0200, Arnd Hannemann wrote:
>>> Thanks for doing the bisect! Can we also see your .config also?
>> Config for -rc7 is attached. My bisect configs were based on that
>
> Thanks! While we wait for the Xen people, you can try the following
> patch to see if we can narrow the bug down to trap_init().

Yes seems to be trap_init().
-rc7 with this patch applied boots up to the prompt.

Best regards, Arnd

>
> diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index
> 3cd7711..7e8e4e4 100644 --- a/arch/x86/mm/init_32.c +++
> b/arch/x86/mm/init_32.c @@ -956,8 +956,10 @@ void __init
> mem_init(void) BUG_ON(VMALLOC_START                >= VMALLOC_END);
> BUG_ON((unsigned long)high_memory        > VMALLOC_START);
>
> +#if 0 if (boot_cpu_data.wp_works_ok < 0) test_wp_bit(); +#endif
>
> save_pg_dir(); zap_low_mappings(true); diff --git a/init/main.c
> b/init/main.c index 2d9d6bd..5c4dacb 100644 --- a/init/main.c +++
> b/init/main.c @@ -603,7 +603,6 @@ asmlinkage void __init
> start_kernel(void) pidhash_init(); vfs_caches_init_early();
> sort_main_extable(); -    trap_init(); mm_init(); /* * Set up the
> scheduler prior starting any interrupts (such as the @@ -621,6 +620,7
> @@ asmlinkage void __init start_kernel(void) "enabled *very* early,
> fixing it\n"); local_irq_disable(); } +    trap_init(); rcu_init(); /*
> init some links before init_ISA_irqs() */ early_irq_init();
>
>