Re: [PATCH 02 of 66] mm, migration: Fix race between shift_arg_pages and rmap_walk by guaranteeing rmap_walk finds PTEs created within the temporary stack

Andrea Arcangeli
2010-11-19T19:27:24Z

On Fri, Nov 19, 2010 at 09:54:27AM -0800, Linus Torvalds wrote:
> On Fri, Nov 19, 2010 at 9:38 AM, Andrea Arcangeli <aarcange@redhat.com> wrote:
> >
> > We decided the kmalloc was ok, but Linus didn't like this approach. I
> > kept it in my tree because I didn't want to remember when/if to add the
> > special check in the accurate rmap walks. I find it simpler if all
> > rmap walks are accurate by default.
>
> Why isn't the existing cheap solution sufficient?

It is sufficient.

> My opinion is still that we shouldn't add the expense to the common
> case, and it's the uncommon case (migration) that should just handle
> it.

Ok, I'll remove this patch from the next submit.