From: Dave Young <dyoung@redhat.com>
Date: Wed, 28 Mar 2012 21:42:47 +0000 (-0700)
Subject: kdump x86: fix total mem size calculation for reservation
X-Git-Tag: v3.4-rc1~53^2~20
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09c71bfd8384278c42f56380365940508194cec0;p=pandora-kernel.git

kdump x86: fix total mem size calculation for reservation

crashkernel reservation need know the total memory size.  Current
get_total_mem simply use max_pfn - min_low_pfn.  It is wrong because it
will including memory holes in the middle.

Especially for kvm guest with memory > 0xe0000000, there's below in qemu
code: qemu split memory as below:

    if (ram_size >= 0xe0000000 ) {
        above_4g_mem_size = ram_size - 0xe0000000;
        below_4g_mem_size = 0xe0000000;
    } else {
        below_4g_mem_size = ram_size;
    }

So for 4G mem guest, seabios will insert a 512M usable region beyond of
4G.  Thus in above case max_pfn - min_low_pfn will be more than original
memsize.

Fixing this issue by using memblock_phys_mem_size() to get the total
memsize.

Signed-off-by: Dave Young <dyoung@redhat.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

Reading git-diff-tree failed