Re: [PATCH] mm: check the return value of lookup_page_ext for all call sites

From: Andrew Morton
Date: Fri May 27 2016 - 16:30:09 EST


On Fri, 27 May 2016 13:17:19 -0700 "Shi, Yang" <yang.shi@xxxxxxxxxx> wrote:

> >> Actually, I think the #ifdef should be removed if lookup_page_ext() is
> >> possible to return NULL. It sounds not make sense returning NULL only
> >> when DEBUG_VM is enabled. It should return NULL no matter what debug
> >> config is selected. If Joonsoo agrees with me I'm going to come up with
> >> a patch to fix it.
> >>
> >
> > I've lost the plot here. What is the status of this patch?
> >
> > Latest version:
>
> Yes, this is the latest version. We are discussing about some future
> optimization.
>
> And, Minchan Kim pointed out a possible race condition which exists even
> before this patch. I proposed a quick fix, as long as they are happy to
> the fix, I will post it to the mailing list.

OK, thanks - I've moved it into the for-Linus-next-week queue.