Thank you Mulyadi, On 7/10/08, Mulyadi Santosa <mulyadi.santosa@xxxxxxxxx> wrote: > > > > 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. > Ok, to summarize: 1. __get_free_pages(GFP_HIGHMEM, order)---> it will be from ZONE_HIGHMEM 2. Or alloc_pages(GFP_HIGHMEM, order). 3. After these just kmap() them to get the virtual address, right? Thank you very much. -- Regards, Peter Teoh -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
