slub: Deal with hyperthetical case of PAGE_SIZE > 2M

kmalloc_index() currently returns -1 if the PAGE_SIZE is larger than 2M
which seems to cause some concern since the callers do not check for -1.

Insert a BUG() and add a comment to the -1 explaining that the code
cannot be reached.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
This commit is contained in:
Christoph Lameter 2011-05-20 09:42:48 -05:00 committed by Pekka Enberg
parent 442b06bcea
commit 3e0c2ab67e

View File

@ -177,7 +177,8 @@ static __always_inline int kmalloc_index(size_t size)
if (size <= 4 * 1024) return 12;
/*
* The following is only needed to support architectures with a larger page
* size than 4k.
* size than 4k. We need to support 2 * PAGE_SIZE here. So for a 64k page
* size we would have to go up to 128k.
*/
if (size <= 8 * 1024) return 13;
if (size <= 16 * 1024) return 14;
@ -188,7 +189,8 @@ static __always_inline int kmalloc_index(size_t size)
if (size <= 512 * 1024) return 19;
if (size <= 1024 * 1024) return 20;
if (size <= 2 * 1024 * 1024) return 21;
return -1;
BUG();
return -1; /* Will never be reached */
/*
* What we really wanted to do and cannot do because of compiler issues is: