Re: [PATCH] x86: Move crashkernel reservation before dma32_reserve_bootmem()

["Yinghai Lu" <yhlu.kernel@gmail.com>]

On Thu, Jul 17, 2008 at 3:15 PM, Bernhard Walle <bwalle@suse.de> wrote:
> On a x86-64 machine (nothing special I could encounter) I had the problem that
> crashkernel reservation with the usual "64M@16M" failed. While debugging that,
> I encountered that dma32_reserve_bootmem() reserves a memory region which is in
> that area.
>
> Because dma32_reserve_bootmem() does not rely on a specific offset but
> crashkernel does, it makes sense to move the crashkernel reservation up a bit.
> I tested that patch and it works without problems. I don't see any negative
> effects of that move, but maybe I oversaw something ...
>
> While we strictly don't need that patch in 2.6.27 because we have the
> automatic, dynamic offset detection, it makes sense to also include it here
> because:
>
>  - it's easier to get it in -stable then,
>  - many people are still used to the 'crashkernel=...@16M' syntax,
>  - not everybody may be using a reloatable kernel.
>
> Signed-off-by: Bernhard Walle <bwalle@suse.de>
> ---
>  arch/x86/kernel/setup.c |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 531b55b..16101c0 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -792,6 +792,12 @@ void __init setup_arch(char **cmdline_p)
>
>        initmem_init(0, max_pfn);
>
> +       /*
> +        * dma32_reserve_bootmem() allocates bootmem which may conflict
> +        * with the crashkernel command line, so do that before
> +        */
> +       reserve_crashkernel();
> +
>  #ifdef CONFIG_X86_64
>        dma32_reserve_bootmem();
>  #endif
> @@ -808,7 +814,6 @@ void __init setup_arch(char **cmdline_p)
>         */
>        find_smp_config();
>  #endif
> -       reserve_crashkernel();
>
>        reserve_ibft_region();
>

Joe Jin already had another one to move dma32_reserve_bootmem later

YH