Re: [PATCH]Fix broken VMI in 2.6.27-rc..

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

On Thu, Aug 7, 2008 at 4:51 PM, H. Peter Anvin <hpa@kernel.org> wrote:
> Jeremy Fitzhardinge wrote:
>>
>> H. Peter Anvin wrote:
>>>
>>> The fixmap area should never have been made movable.  It's utter
>>> braindamage.
>>
>> Shrug.  It's been like that for a couple of years now.  It was one of the
>> very first paravirt-ops patches.  It wasn't controversial then, and nobody
>> seems to have noticed since.
>
> The Linux kernel was never a paragon of perfection - it was never meant to
> be.  Just because a bit of cruft went unnoticed into the kernel doesn't mean
> we shouldn't fix it.
>
>>> Given the x86 architecture, it's inevitable that PV will want to reserve
>>> address space at the top of memory, and therefore the fixmap area needs to
>>> be moved out of that space.
>>
>> OK.  But there's a few places where the code uses FIXADDR_TOP to mean "top
>> of kernel address space", so we'd need to come up with a proper symbol for
>> that.

why not reserving that in e820 table?

YH