Re: objrmap and vmtruncate

William Lee Irwin III
2003-04-06T21:35:37Z

Andrea Arcangeli <andrea@suse.de> wrote:
>>> Esepcially those sigbus in the current api
>>> would be more expensive than the regular paging internal to the VM and
>>> besides the signal it would generate flood of syscalls and kind of
>>> duplication of memory management inside the userspace.

On Sat, Apr 05, 2003 at 05:58:24PM -0800, Andrew Morton wrote:
>> That went away. We now encode the file offset in the unmapped ptes, so the
>> kernel's fault handler can transparently reestablish the page.

On Sun, Apr 06, 2003 at 04:47:34PM +0200, Andrea Arcangeli wrote:
> if you put the file offset in the pte, you will break the max file
> offset that you can map, that at least should be recoded with a cookie
> like we do with the swap space

IIRC we just restricted the size of the file that can use the things to
avoid having to code quite so much up.

-- wli