Re: [patch 4/6] mm: merge populate and nopage into fault (fixes nonlinear)

Peter Zijlstra
2007-03-07T10:26:20Z

On Wed, 2007-03-07 at 11:21 +0100, Nick Piggin wrote:
> On Wed, Mar 07, 2007 at 11:13:20AM +0100, Miklos Szeredi wrote:
> > > *sigh* yes was looking at all that code, thats gonna be darn slow
> > > though, but I'll whip up a patch.
> >
> > Well, if it's going to be darn slow, maybe it's better to go with
> > mingo's plan on emulating nonlinear vmas with linear ones. That'll be
>
> There are real users who want these fast, though.

Yeah, why don't we have a tree per nonlinear vma to find these pages?

wli mentions shadow page tables..

> > darn slow as well, but at least it will be much less complicated.
>
> IMO, the best thing to do is just restore msync behaviour, and comment
> the fact that we ignore nonlinears. We need to restore msync behaviour
> to fix races in regular mappings anyway, at least for now.

Seems to be the best quick solution indeed.