Messages in this thread | | | Date | Sat, 16 Jun 2012 14:10:56 +0800 | Subject | Re: [PATCH] swap: fix shmem swapping when more than 8 areas | From | Cong Wang <> |
| |
On Sat, Jun 16, 2012 at 12:56 PM, Wanpeng Li <liwp.linux@gmail.com> wrote: >>-#define SWP_TYPE_SHIFT(e) (sizeof(e.val) * 8 - MAX_SWAPFILES_SHIFT) >>+#define SWP_TYPE_SHIFT(e) ((sizeof(e.val) * 8) - \ >>+ (MAX_SWAPFILES_SHIFT + RADIX_TREE_EXCEPTIONAL_SHIFT)) > > Hi Hugh, > > Since SHIFT == MAX_SWAPFILES_SHIFT + RADIX_TREE_EXCEPTIONAL_SHIFT == 7 > and the low two bits used for radix_tree, the available swappages number > based of 32bit architectures reduce to 2^(32-7-2) = 32GB? >
The lower two bits are in the 7 bits you calculated, so it is 2^(32-7), not 2^(32-7-2) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |