[PATCH] Fix ppc64 max_pfn issue

I noticed excessive time in the pid hash functions on a ppc64 box. It
turns out the pid hash is being sized way too small, eg on a 16GB box:

PID hash table entries: 16 (order 4: 256 bytes)

The reason is that the pid hash init function uses max_pfn before it was
setup on ppc64. With the following patch things are good again:

PID hash table entries: 4096 (order 12: 65536 bytes)
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc64/mm/init.c

@@ -533,6 +533,8 @@ void __init do_init_bootmem(void)
 	unsigned long total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 	int boot_mapsize;
 
+        max_pfn = max_low_pfn;
+
 	/*
 	 * Find an area to use for the bootmem bitmap.  Calculate the size of
 	 * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
@@ -629,7 +631,6 @@ void __init mem_init(void)
 
 	num_physpages = max_low_pfn;	/* RAM is assumed contiguous */
 	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
-	max_pfn = max_low_pfn;
 
 #ifdef CONFIG_DISCONTIGMEM
 {

arch/ppc64/mm/numa.c

@@ -356,6 +356,7 @@ void __init do_init_bootmem(void)
 
 	min_low_pfn = 0;
 	max_low_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
+	max_pfn = max_low_pfn;
 
 	if (parse_numa_properties())
 		setup_nonnuma();