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

Bernhard Walle bwalle at suse.de
Sun Jul 13 14:49:44 EDT 2008

From: Bernhard Walle <bernhard.walle at gmx.de>

On a x86-64 machine (nothing special I could encounter) I had the problem that
crashkernel reservation with the usual "64M at 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 the long-term solution is to make the crashkernel reservation dynamic
(which is already done in -tip), this bug should be fixed also short-term for
2.6.26 (or 2.6.26-stable if it's too short), and that's why I made that patch.

Signed-off-by: Bernhard Walle <bwalle at suse.de>
Signed-off-by: Bernhard Walle <bernhard.walle at gmx.de>
 arch/x86/kernel/setup_64.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 6dff128..158cefe 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -444,6 +444,12 @@ void __init setup_arch(char **cmdline_p)
 	contig_initmem_init(0, end_pfn);
+	/*
+	 * dma32_reserve_bootmem() allocates bootmem which may conflict
+	 * with the crashkernel command line, so do that before
+	 */
+	reserve_crashkernel();
@@ -484,7 +490,6 @@ void __init setup_arch(char **cmdline_p)
-	reserve_crashkernel();

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