Hi... On Thu, Jul 10, 2008 at 3:02 PM, Peter Teoh <htmldeveloper@xxxxxxxxx> wrote: > From previous posting, Mulyadi mentioned that page mapping in > ZONE_NORMAL being the default mapping. I think better wording is: pages are taken from ZONE_NORMAL, if no flags like GFP_HIGHMEM isn't mentioned. > So my questions are these: > > If default mapping (via cr3/pgd mechanism) is ZONE_NORMAL, then how do > we allocate memory in the ZONE_HIGHMEM region? (ie, does > __get_free_pages() or alloc_pages() return us anything in those > region?) > Don't get confused, alloc_pages() has no problem "touching" highmem pages. The problem is, when you need to address those pages (I am sure you realize this issue too), you need to map them into kernel address space. That's where kmap() or kmap_atomic() comes into rescue. regards, Mulyadi. -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
