Re: [PATCH 1/5] resources: add arch hook for preventing allocation in reserved areas

[Jesse Barnes <jbarnes@virtuousgeek.org>]

[Actually cc'ing Matthew this time]

On Fri, 10 Dec 2010 12:30:08 -0800
Jesse Barnes <jbarnes@virtuousgeek.org> wrote:

> On Wed, 08 Dec 2010 14:36:06 -0700
> Bjorn Helgaas <bjorn.helgaas@hp.com> wrote:
> 
> > 
> > This adds arch_remove_reservations(), which an arch can implement if it
> > needs to protect part of the address space from allocation.
> > 
> > Sometimes that can be done by just requesting a resource.  This hook is to
> > cover cases where protected area doesn't fit well in the hierarchical
> > resource tree.  For example, x86 BIOS E820 reservations are not related
> > to devices, so they may overlap part of, all of, or more than a device
> > resource.
> > 
> > Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
> > ---
> 
> Hm, this is bigger than the simple change of just avoiding the high 2M;
> Linus have you checked it out yet?  It's nicer than simply adjusting
> PCIBIOS_MAX_MEM since it will affect all resource callers rather than
> just PCI, but it's definitely bigger.
> 
> If you want just the simple change for 2.6.37 I can push that, but
> we'll need to get a tested-by from Matthew:
> 
>   diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
>   index ca0437c..aef9f77 100644
>   --- a/arch/x86/include/asm/pci.h
>   +++ b/arch/x86/include/asm/pci.h
>   @@ -141,7 +141,7 @@ void dma32_reserve_bootmem(void);
> 
>    /* generic pci stuff */
>    #include <asm-generic/pci.h>
>   -#define PCIBIOS_MAX_MEM_32 0xffffffff
>   +#define PCIBIOS_MAX_MEM_32 0xfff00000
> 
>    #ifdef CONFIG_NUMA
>    /* Returns the node based on pci bus */
> 
> and I'll queue up this set for 2.6.38.
> 
> Thanks,


-- 
Jesse Barnes, Intel Open Source Technology Center