Re: [PATCH prototype] [0/8] Predictive bitmaps for ELF executables

Andi Kleen
2008-03-19T21:45:26Z

On Tue, Mar 18, 2008 at 10:44:37AM -0700, Andrew Morton wrote:
> On Tue, 18 Mar 2008 18:20:45 +0100 Andi Kleen <andi@firstfloor.org> wrote:
>
> > > What's the permission problem? executable-but-not-readable files? Could
> >
> > Not writable.
>
> Oh.
>
> I doubt if a userspace implementation would even try to alter the ELF
> files, really - there seems to be no point in it. This is just complexity

Well the information has to be somewhere and i think the ELF file
is the best location for it. It makes it the most user transparent.

> > Yes it could, but i dont even want to thi nk about all the issues of
> > doing such an interface. It is basically an microkernelish approach.
> > I prefer monolithic simplicity.
>
> It's not complex at all. Pass a null-terminated pathname to the server and
> keep running. The server will asynchronously read your pages for you.

But how do you update the bitmap in your scheme?

> > And I am really not a friend of unnecessary complexity. In the end
> > complexity hurts you, no matter if it is in ring 3 or ring 0.
>
> There is no complexity here.

I have my doubts on that if you consider update too.

-Andi
>