Re: 2.6.28-rc9 panics with crashkernel=256M while booting

From: Chandru
Date: Mon Jan 19 2009 - 06:30:26 EST


In case either physbase or reserve_size are not page aligned and in addition
if the following condition is also true

node_ar.end_pfn = node->node_end_pfn = PFN_DOWN(physbase+reserve_size).

we may hit the BUG_ON(end > bdata->node_low_pfn) in mark_bootmem_node() in
mm/bootmem.c Hence pass the pfn that the physbase is part of and align
reserve_size before calling reserve_bootmem_node().

Signed-off-by: Chandru S <chandru@xxxxxxxxxxxxxxxxxx>
Cc: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/mm/numa.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- linux-2.6.29-rc2/arch/powerpc/mm/numa.c.orig 2009-01-19 16:14:49.000000000 +0530
+++ linux-2.6.29-rc2/arch/powerpc/mm/numa.c 2009-01-19 16:36:38.000000000 +0530
@@ -901,7 +901,8 @@ static void mark_reserved_regions_for_ni
get_node_active_region(start_pfn, &node_ar);
while (start_pfn < end_pfn &&
node_ar.start_pfn < node_ar.end_pfn) {
- unsigned long reserve_size = size;
+ unsigned long reserve_size = (size >> PAGE_SHIFT) <<
+ PAGE_SHIFT;
/*
* if reserved region extends past active region
* then trim size to active region
@@ -917,7 +918,8 @@ static void mark_reserved_regions_for_ni
dbg("reserve_bootmem %lx %lx nid=%d\n",
physbase, reserve_size, node_ar.nid);
reserve_bootmem_node(NODE_DATA(node_ar.nid),
- physbase, reserve_size,
+ (start_pfn << PAGE_SHIFT),
+ reserve_size,
BOOTMEM_DEFAULT);
}
/*

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