Re: Introducing non-RAM managed page ("device page")

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Tue, Sep 15, 2009 at 04:04:15PM +0000, Eduardo Horvath wrote:
> We've handled mmap()ing device memory forever without getting VM involved.  
> Not to imply that the current device mmap() interface could not be 
> improved.  What features of the VM subsystem do you think is needed to map 
> device pages into processes?

This is *not* mmap on a device. It is mmap of a file stored on a special
device. In other words, read-only access to this device can be done
without the buffer cache and for that the VM subsystem needs glue.

Joerg