kernel: getting rid of duppage() (thanks charles)

simplifying paging code by getting rid of duppage(). instead,
fixfault() now always makes a copy of the shared/cached page
and leaves the cache alone. newpage() uncaches pages as
neccesary.

thanks charles forsyth for the suggestion.

from http://9fans.net/archive/2014/03/26:

> It isn't needed at all. When a cached page is written, it's trying hard to
> replace the page in the cache by a new copy,
> to return the previously cached page. Instead, I copy the cached page and
> return the copy, which is what it already
> does in another instance. ...

0 files changed, 0 insertions, 0 deletions