On Mon, Feb 08, 2010 at 11:40:50AM +0900, Masao Uebayashi wrote: > I'm adding another list of vm_physseg for device pages. It's a > list or array of physical address segments. They're frequently > accessed by VM to lookup a physical address from a page metadata > (vm_page) or vice versa. > > Those lists are rarely updated. When a framebuffer or > memory-mappable audio device are attached / detached. (For RAM > segments, they're updated when we'll support memory hot-plug. :) > > The update process is very rare, and expected. Administrators > carefully connects a device when the machine is not running some > important task. So what I need here is to protect such a data > adding no run-time performance loss.
On the plus side, this is essentially the same problem as safely switching vnodes to deadfs after a umount -f; on the minus side, nobody's yet come up with a satisfactory solution for that... -- David A. Holland [email protected]
