Index: linux-2.6.19-rc6-mm2/mm/hugetlb.c
===================================================================
--- linux-2.6.19-rc6-mm2.orig/mm/hugetlb.c	2006-12-04 11:57:01.000000000 -0800
+++ linux-2.6.19-rc6-mm2/mm/hugetlb.c	2006-12-04 11:58:02.000000000 -0800
@@ -16,7 +16,6 @@
 #include <linux/pagemap.h>
 #include <linux/mempolicy.h>
 #include <linux/cpuset.h>
-#include <linux/mutex.h>
 
 #include <asm/page.h>
 #include <asm/pgtable.h>
@@ -35,15 +34,8 @@
  *
  * 2. The page_table_lock is used to synchronize page table updates
  *
- * 3. There is another global mutex hugetlb_instantiation_mutex
- * 	serializing all huge page faults which currently limits the
- * 	scalability of huge pages. This lock insures that no new
- * 	allocations are performed between the allocation of a huge
- * 	page and the installation of the page table entry.
- *
  * Lock order:
  * 	mmap_sem
- * 	hugetlb_instantiation_mutex
  * 	page_table_lock
  * 	hugetlb_lock
  */
@@ -564,22 +556,14 @@
 	pte_t *ptep;
 	pte_t entry;
 	int ret;
-	static DEFINE_MUTEX(hugetlb_instantiation_mutex);
 
 	ptep = huge_pte_alloc(mm, address);
 	if (!ptep)
 		return VM_FAULT_OOM;
 
-	/*
-	 * Serialize hugepage allocation and instantiation, so that we don't
-	 * get spurious allocation failures if two CPUs race to instantiate
-	 * the same page in the page cache.
-	 */
-	mutex_lock(&hugetlb_instantiation_mutex);
 	entry = *ptep;
 	if (pte_none(entry)) {
 		ret = hugetlb_no_page(mm, vma, address, ptep, write_access);
-		mutex_unlock(&hugetlb_instantiation_mutex);
 		return ret;
 	}
 
@@ -591,7 +575,6 @@
 		if (write_access && !pte_write(entry))
 			ret = hugetlb_cow(mm, vma, address, ptep, entry);
 	spin_unlock(&mm->page_table_lock);
-	mutex_unlock(&hugetlb_instantiation_mutex);
 
 	return ret;
 }