[PATCH] x86: Find offset for crashkernel reservation automatically

[Eric W. Biederman]

Bernhard Walle <bwalle at suse.de> writes:

> * Yinghai Lu [2008-07-14 00:11]:
>>
>> should use min_t(u64, 1ULL<<32, max_low_pfn<<PAGE_SHIFT) replace ULONG_MAX
>
> Shouldn't we use  min_t(u64, ULLONG_MAX, max_low_pfn<<PAGE_SHIFT), i.e.
> should we really limit the crashkernel to a 32 bit address on a 64 bit
> system?

We should use the lowest physical address that meets our size and
alignment constraints.  However there is no reason to make this be <
4G or even < 1G.  The worst case is that we reserve an area the kdump
kernel can't run out of.  However /sbin/kexec should check for that as
the kexec on panic code is not necessarily a linux kernel.

Eric