# TODO File for core-team member:		John Dyson
# Revision: dyson,v 1.1 1995/04/10 06:10:05 dyson Exp
#
# This is my publically readable TODO file, showing the things I have on
# my TODO list.
#
-*----------------------------------------------------------------------------*-

Update: Sun Apr 9, 1995
Due:	2.2, maybe 2.1
Prio:	High
Task:	Implement full VOP_GETPAGE/VOP_PUTPAGE interface

The current vnode pager violates the vfs layering.  Prototype mods have
already been implemented.  Since the VM system and VFS systems are
central to the reliable operation of the system, and other filesystems will
be worked on by 2.1, this change will be added to 2.1 only if it is very
smooth to integrate.  It will probably be placed into -current immediately
after 2.1 release, before which I will have tested the code.  The good side
of the 2.1 or pre 2.1 implementation is that it currently has no known
negative side-effects and is about as CPU efficient as it can get.


Update: Sun Apr 9, 1995
Due:	2.2
Prio:	Medium
Task:	Implement proper page fault handling of non-page aligned (offset 1k
	or other) binary formats.

The task says it all.  Currently, some of the non-native executable loaders
have work-arounds for this.


Update: Sun Apr 9, 1995
Due:	2.2
Prio:	Medium
Task:	Change the object page list into a tree representation.

Since we now have a properly working merged-VM buffer cache mechanism, it
is likely that more file modifications will be done by the mmap mechanism.
Unfortunately, some of the VM data structures inherited from MACH are not
very efficient at handling this kind of output.  We will implement a much
more efficient method of handling the flushing of modified pages.  This
is a very basic and simple change, and will have the added benefit of
improving the efficiency of ordered traversal of pages in objects in general.

Update: Sun Apr 9, 1995
Due:	2.2, maybe 2.1
Prio:	Medium
Task:	Allow simple paging to files, and turning off such paging

We currently can page to files through the vn device.  This is a bit
of hackery -- and there is no way to turn off paging to such a file.  If
there is enough swap space, it should be easy to turn off paging to either
an explicit swap file or paging to/from any physical device, and force
the swap/page-ins.


