Re: [mm][RFC][PATCH 0/11] mm accessor updates.

Andi Kleen
2009-12-16T10:50:06Z

On Wed, Dec 16, 2009 at 07:31:09PM +0900, KAMEZAWA Hiroyuki wrote:
> On Wed, 16 Dec 2009 11:28:06 +0100
> Andi Kleen <andi@firstfloor.org> wrote:
>
> > > > Also the patches didn't fare too well in testing unfortunately.
> > > >
> > > > I suspect we'll rather need multiple locks split per address
> > > > space range.
> > >
> > > This set doesn't include any changes of the logic. Just replace all mmap_sem.
> > > I think this is good start point (for introducing another logic etc..)
> >
> > The problem is that for range locking simple wrapping the locks
> > in macros is not enough. You need more changes.
> >
> maybe. but removing scatterred mmap_sem from codes is the first thing to do.
> I think this removing itself will take 3 month or a half year.
> (So, I didn't remove mmap_sem and leave it as it is.)

I suspect you would just need to change them again then.

> The problem of range locking is more than mmap_sem, anyway. I don't think
> it's possible easily.

Yes, it has some tricky aspects. But my feeling is that there's no good
alternative to it for real scalability.

-Andi
--
ak@linux.intel.com -- Speaking for myself only.