mm: also use alloc_large_system_hash() for the PID hash table

This is being done by allowing boot time allocations to specify that they
may want a sub-page sized amount of memory.

Overall this seems more consistent with the other hash table allocations,
and allows making two supposedly mm-only variables really mm-only
(nr_{kernel,all}_pages).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 3 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 33b1a4762a7b..770f011e1c12 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -124,8 +124,8 @@ static char * const zone_names[MAX_NR_ZONES] = {
 
 int min_free_kbytes = 1024;
 
-unsigned long __meminitdata nr_kernel_pages;
-unsigned long __meminitdata nr_all_pages;
+static unsigned long __meminitdata nr_kernel_pages;
+static unsigned long __meminitdata nr_all_pages;
 static unsigned long __meminitdata dma_reserve;
 
 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
@@ -4821,7 +4821,14 @@ void *__init alloc_large_system_hash(const char *tablename,
                         numentries <<= (PAGE_SHIFT - scale);
 
                 /* Make sure we've got at least a 0-order allocation.. */
-                if (unlikely((numentries * bucketsize) < PAGE_SIZE))
+                if (unlikely(flags & HASH_SMALL)) {
+                        /* Makes no sense without HASH_EARLY */
+                        WARN_ON(!(flags & HASH_EARLY));
+                        if (!(numentries >> *_hash_shift)) {
+                                numentries = 1UL << *_hash_shift;
+                                BUG_ON(!numentries);
+                        }
+                } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
                         numentries = PAGE_SIZE / bucketsize;
         }
         numentries = roundup_pow_of_two(numentries);