Hi Nick,

Thanks for your reply again, ;-).

On 12/19/06, Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
> This should not happen because the pages are checked to ensure they are
> from the same zone before merging.

How? page_is_buddy() only check if the buddy has the buddy flag and
has the same order.
Where can I find the same zone is checked?

>
> What kind of system do you have? What is the dmesg and the .config?

I'm using the blackfin uclinux. dmesg and .config is attached.

> It could be that the zones are not properly aligned and CONFIG_HOLES_IN_ZONE
> is not set.

I changed the code in paging_init(), see below:
-----------------------------------------
#if 0
                zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
                zones_size[ZONE_NORMAL] = 0;
#else
                zones_size[ZONE_DMA] = (end_mem/2 - PAGE_OFFSET) >> PAGE_SHIFT;
                zones_size[ZONE_NORMAL] = (end_mem/2 - PAGE_OFFSET) >>
PAGE_SHIFT;
#endif
-----------------------------------------
This is only what I did the change. I also suspect the zones are not
properly aligned, But how to align it? I think our system doesn't need
CONFIG_HOLES_IN_ZONE.

Thanks,
-Aubrey