Re: anon_vma RFC2

Hugh Dickins
2004-03-12T16:13:10Z

On Fri, 12 Mar 2004, Andrea Arcangeli wrote:
> On Fri, Mar 12, 2004 at 01:43:23PM +0000, Hugh Dickins wrote:
>
> Don't forget you can't re-use the vma->shared for doing the tmpfs-style
> thing, that's already in a true inode.

Good point, I was overlooking that. I'll see if I can come up with
something, but that may well prove a killer.

> you're right about vma_split, the way I implemented it is wrong,
> basically the as.vma/PageDirect idea is falling apart with vma_split.
> I should simply allocate the anon_vma without passing through the direct

Yes, that'll take a lot of the branching out, all much simpler.

> mode, that will fix it though it'll be a bit less efficient for the
> first page fault in an anonymous vma (only the first one, for all the
> other page faults it'll be as fast as the direct mode).

Simpler still to allocate it earlier? Perhaps too wasteful.

Hugh