Messages in this thread | | | Date | Thu, 14 Oct 2010 13:18:33 +0800 | From | Américo Wang <> | Subject | Re: dear list |
| |
On Thu, Sep 02, 2010 at 02:51:48PM +0800, gaoqiang wrote: >I'm a newbie and got some question when learning the linux kernel > >about a macro: > >page_to_pfn(pg) > >I traced its definition,and finally got that: > >#define __page_to_pfn(page) ((unsigned long)((page) - mem_map) + >ARCH_PFN_OFFSET) > > >why hot ((unsigned long)((page)-mem_map + ARCH_PFN_OFFSET)/sizeof >(struct page) >
Sorry for the really long delay.
That is because both 'page' and 'mem_map' have type 'struct page *'.
| |