[patch 3/3] arch_rebalance_pgtables call

[schwidefsky@de.ibm.com]

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From: Martin Schwidefsky <schwidefsky@de.ibm.com>

In order to change the layout of the page tables after an mmap has
crossed the adress space limit of the current page table layout a
architecture hook in get_unmapped_area is needed. The arguments
are the address of the new mapping and the length of it.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 mm/mmap.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Index: linux-2.6/mm/mmap.c
===================================================================
--- linux-2.6.orig/mm/mmap.c
+++ linux-2.6/mm/mmap.c
@@ -36,6 +36,10 @@
 #define arch_mmap_check(addr, len, flags)	(0)
 #endif
 
+#ifndef arch_rebalance_pgtables
+#define arch_rebalance_pgtables(addr, len)		(addr)
+#endif
+
 static void unmap_region(struct mm_struct *mm,
 		struct vm_area_struct *vma, struct vm_area_struct *prev,
 		unsigned long start, unsigned long end);
@@ -1436,7 +1440,7 @@ get_unmapped_area(struct file *file, uns
 	if (addr & ~PAGE_MASK)
 		return -EINVAL;
 
-	return addr;
+	return arch_rebalance_pgtables(addr, len);
 }
 
 EXPORT_SYMBOL(get_unmapped_area);

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.