On Mon, Apr 02, 2012 at 02:18:34PM +0200, Samuel Thibault wrote: > But then it needs some trick to convert to pointer everywhere needed. > Trying to manage low-4GiB allocation to avoid the trick would make > things nasty: remember that x86_64 does not have segmentation any more, > only flat addressing space, so we'd still need a 4GiB User/Kernel > separation, which was precisely what I wanted to avoid.
I'm not following there. The conversion to pointer would be a simple lookup (changing all occurrences in the kernel can be tedious, agreed). I don't see the relation with segmentation and the 4GiB split. What is the layout you expect for the kernel space ? First 4 GiB user then kernel ? And you thought of segmentation to implicitely shift addresses ? IMHO, changing GNU Mach to cleanly convert port names where needed remains the sane choice. -- Richard Braun
