Re: [PATCH 0/1] expand_downwards: don't require the gap if !vm_prev

[Oleg Nesterov]

On 06/29, Linus Torvalds wrote:
>
> On Thu, Jun 29, 2017 at 8:19 AM, Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> >
> > Hmm. May be you misread this patch?
>
> Ahh, yes. I'm ok with your patch.
>
> That said, you did remove something extra: the comment about
>
>     /* Check that both stack segments have the same anon_vma? */

I didn't ;) I moved it up, right above VM_GROWSDOWN check.


> is actually still relevant wrt that VM_GROWSDOWN test. The issue is
> that we could actually limit the VM_GROWSDOWN thing to only be ok with
> merging with a previous vma only if it *really* was the same segment.

Yes, yes, this is clear. This comment motivated me to ask that question,
I thought that we probably do not need to reconcile the stacks even in
this case.

Oleg.