diff -uprN -X linux-2.6.18-rc1.orig/Documentation/dontdiff linux-2.6.18-rc1.orig/arch/i386/Kconfig linux-2.6.18-rc1.unsorted_groups/arch/i386/Kconfig
--- linux-2.6.18-rc1.orig/arch/i386/Kconfig	2006-07-07 13:12:20.000000000 +1200
+++ linux-2.6.18-rc1.unsorted_groups/arch/i386/Kconfig	2006-07-07 11:46:34.000000000 +1200
@@ -258,6 +258,7 @@ config SCHED_MC
 	  increased overhead in some places. If unsure say N here.
 
 source "kernel/Kconfig.preempt"
+source "kernel/Kconfig.unsortedgroups"
 
 config X86_UP_APIC
 	bool "Local APIC support on uniprocessors"
diff -uprN -X linux-2.6.18-rc1.orig/Documentation/dontdiff linux-2.6.18-rc1.orig/arch/mips/Kconfig linux-2.6.18-rc1.unsorted_groups/arch/mips/Kconfig
--- linux-2.6.18-rc1.orig/arch/mips/Kconfig	2006-07-07 13:12:22.000000000 +1200
+++ linux-2.6.18-rc1.unsorted_groups/arch/mips/Kconfig	2006-07-07 11:46:34.000000000 +1200
@@ -1820,6 +1820,7 @@ config HZ
 	default 1024 if HZ_1024
 
 source "kernel/Kconfig.preempt"
+source "kernel/Kconfig.unsortedgroups"
 
 config RTC_DS1742
 	bool "DS1742 BRAM/RTC support"
diff -uprN -X linux-2.6.18-rc1.orig/Documentation/dontdiff linux-2.6.18-rc1.orig/arch/parisc/Kconfig linux-2.6.18-rc1.unsorted_groups/arch/parisc/Kconfig
--- linux-2.6.18-rc1.orig/arch/parisc/Kconfig	2006-07-07 13:12:23.000000000 +1200
+++ linux-2.6.18-rc1.unsorted_groups/arch/parisc/Kconfig	2006-07-07 11:46:34.000000000 +1200
@@ -220,6 +220,7 @@ config NODES_SHIFT
 source "kernel/Kconfig.preempt"
 source "kernel/Kconfig.hz"
 source "mm/Kconfig"
+source "kernel/Kconfig.unsortedgroups"
 
 config COMPAT
 	def_bool y
diff -uprN -X linux-2.6.18-rc1.orig/Documentation/dontdiff linux-2.6.18-rc1.orig/arch/powerpc/Kconfig linux-2.6.18-rc1.unsorted_groups/arch/powerpc/Kconfig
--- linux-2.6.18-rc1.orig/arch/powerpc/Kconfig	2006-07-07 13:12:23.000000000 +1200
+++ linux-2.6.18-rc1.unsorted_groups/arch/powerpc/Kconfig	2006-07-07 11:46:34.000000000 +1200
@@ -593,6 +593,7 @@ config HIGHMEM
 source kernel/Kconfig.hz
 source kernel/Kconfig.preempt
 source "fs/Kconfig.binfmt"
+source "kernel/Kconfig.unsortedgroups"
 
 # We optimistically allocate largepages from the VM, so make the limit
 # large enough (16MB). This badly named config option is actually
diff -uprN -X linux-2.6.18-rc1.orig/Documentation/dontdiff linux-2.6.18-rc1.orig/arch/x86_64/Kconfig linux-2.6.18-rc1.unsorted_groups/arch/x86_64/Kconfig
--- linux-2.6.18-rc1.orig/arch/x86_64/Kconfig	2006-07-07 13:12:26.000000000 +1200
+++ linux-2.6.18-rc1.unsorted_groups/arch/x86_64/Kconfig	2006-07-07 11:46:34.000000000 +1200
@@ -273,6 +273,8 @@ config SCHED_MC
 	  increased overhead in some places. If unsure say N here.
 
 source "kernel/Kconfig.preempt"
+source "kernel/Kconfig.unsortedgroups"
+
 
 config NUMA
        bool "Non Uniform Memory Access (NUMA) Support"
diff -uprN -X linux-2.6.18-rc1.orig/Documentation/dontdiff linux-2.6.18-rc1.orig/kernel/Kconfig.unsortedgroups linux-2.6.18-rc1.unsorted_groups/kernel/Kconfig.unsortedgroups
--- linux-2.6.18-rc1.orig/kernel/Kconfig.unsortedgroups	1970-01-01 12:00:00.000000000 +1200
+++ linux-2.6.18-rc1.unsorted_groups/kernel/Kconfig.unsortedgroups	2006-07-07 11:46:34.000000000 +1200
@@ -0,0 +1,16 @@
+#
+# Groups order
+#
+config USE_UNSORTED_SUPPLEMENTAL_GROUPS
+	bool "Use unsorted supplemental groups"
+	help
+
+	 If you need to use setgroups(2) to order a process's supplemental group list so that you can 
+         choose which 16 groups are sent during a NFSv2 or NFSv3 AUTH_UNIX (the default authentication protocol)
+         transaction you need to say Y here.
+
+         If you do not have users with more than 16 groups who need to access NFS you don't need this.
+
+         Do not set this option if you are going to have users in thousands of secondary groups. The default 
+	 kernel implementation sorts the groups and then binary searches them for membership. This option forces 
+  	 the search to be linear.
diff -uprN -X linux-2.6.18-rc1.orig/Documentation/dontdiff linux-2.6.18-rc1.orig/kernel/sys.c linux-2.6.18-rc1.unsorted_groups/kernel/sys.c
--- linux-2.6.18-rc1.orig/kernel/sys.c	2006-07-07 13:12:44.000000000 +1200
+++ linux-2.6.18-rc1.unsorted_groups/kernel/sys.c	2006-07-11 14:45:08.007916000 +1200
@@ -1535,14 +1535,22 @@ static void groups_sort(struct group_inf
 	}
 }
 
-/* a simple bsearch */
+/* if USE_UNSORTED_SUPPLEMENTAL_GROUPS is set this is a linear search. If not it's a binary search */
 int groups_search(struct group_info *group_info, gid_t grp)
 {
-	unsigned int left, right;
 
 	if (!group_info)
 		return 0;
 
+#ifdef USE_UNSORTED_SUPPLEMENTAL_GROUPS
+	unsigned int i;
+
+	for (i=0; i < group_info->ngroups; i++)
+		if (GROUP_AT(group_info,i) == grp)
+			return 1;
+#else
+	unsigned int left, right;
+
 	left = 0;
 	right = group_info->ngroups;
 	while (left < right) {
@@ -1555,6 +1563,7 @@ int groups_search(struct group_info *gro
 		else
 			return 1;
 	}
+#endif
 	return 0;
 }
 
@@ -1568,7 +1577,10 @@ int set_current_groups(struct group_info
 	if (retval)
 		return retval;
 
+#ifndef USE_UNSORTED_SUPPLEMENTAL_GROUPS
 	groups_sort(group_info);
+#endif
+
 	get_group_info(group_info);
 
 	task_lock(current);