Re: [PATCH resend] mm/page_alloc: fix comment is __get_free_pages

From: Andrew Morton
Date: Fri Dec 15 2017 - 15:57:42 EST


On Fri, 15 Dec 2017 10:36:18 +0100 Michal Hocko <mhocko@xxxxxxxxxx> wrote:

> > >
> > > So do we care and I will resend the patch in that case or I just drop
> > > this from my patch queue?
> >
> > Well.. I still think that silently accepting bad input would be bad
> > practice. If we can just delete the assertion and have such a caller
> > reliably blow up later on then that's good enough.
>
> The point is that if the caller checks for the failed allocation then
> the result is a memory leak.

That's if page_address(highmem page) returns NULL. I'm not sure what
it returns, really - so many different implementations across so many
different architectures.

Oh well, it would have been nice to remove that VM_BUG_ON(). Why not
just leave the code as it is now?