[PATCH] fix alloc_large_system_hash() roundup

The "rounded up to nearest power of 2 in size" algorithm in
alloc_large_system_hash is not correct.  As coded, it takes an otherwise
acceptable power-of-2 value and doubles it.  For example, we see the error
if we boot with thash_entries=2097152 which produces a hash table with
4194304 entries.

Signed-off-by: John Hawkes <hawkes@sgi.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 637f57ff5b5a..338a02bb004d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2702,8 +2702,7 @@ void *__init alloc_large_system_hash(const char *tablename,
                 else
                         numentries <<= (PAGE_SHIFT - scale);
         }
-        /* rounded up to nearest power of 2 in size */
-        numentries = 1UL << (long_log2(numentries) + 1);
+        numentries = roundup_pow_of_two(numentries);
 
         /* limit allocation size to 1/16 total memory by default */
         if (max == 0) {