[PATCH] remove unnecessary PAE pgd set

[Dave Hansen <haveblue@us.ibm.com>]

With PAE on, there are only 4 PGD entries.  The kernel ones never
change, so there is no need to copy them when a vmalloc fault occurs.
This was this was causing problems with the split pmd patches, but it is
still correct for mainline.

Tested with and without PAE.  I ran it in a loop turning on and off 10
swap partitions, which is what excited the original bug.
http://bugme.osdl.org/show_bug.cgi?id=640
-- 
Dave Hansen
haveblue@us.ibm.com
--- linux-2.5.68-vmal_fault/arch/i386/mm/fault.c.orig	Wed Apr 30 13:36:49 2003
+++ linux-2.5.68-vmal_fault/arch/i386/mm/fault.c	Wed Apr 30 13:36:18 2003
@@ -405,7 +405,15 @@
 
 		if (!pgd_present(*pgd_k))
 			goto no_context;
+		/*
+		 * kernel pmd pages are shared among all processes
+		 * with PAE on.  Since vmalloc pages are always
+		 * in the kernel area, this will always be a 
+		 * waste with PAE on.
+		 */
+#ifndef CONFIG_X86_PAE
 		set_pgd(pgd, *pgd_k);
+#endif
 		
 		pmd = pmd_offset(pgd, address);
 		pmd_k = pmd_offset(pgd_k, address);