On Thu, Jan 03, 2019 at 10:47:06AM -0800, Tejun Heo wrote:
> Hello,
>
> On Wed, Jan 02, 2019 at 07:05:38PM +0200, Mike Rapoport wrote:
> > I agree that currently the bottom-up allocation after the kernel text has
> > issues with KASLR. But this issues are not necessarily related to the
> > memory hotplug. Even with a single memory node, a bottom-up allocation will
> > fail if KASLR would put the kernel near the end of node0.
> >
> > What I am trying to understand is whether there is a fundamental reason to
> > prevent allocations from [0, kernel_start)?
> >
> > Maybe Tejun can recall why he suggested to start bottom-up allocations from
> > kernel_end.
>
> That's from 79442ed189ac ("mm/memblock.c: introduce bottom-up
> allocation mode"). I wasn't involved in that patch, so no idea why
> the restrictions were added, but FWIW it doesn't seem necessary to me.
I should have added the reference [1] at the first place :)
Thanks!
[1] https://lore.kernel.org/lkml/20130904192215.GG26609@xxxxxxxxxxxxxx/
> Thanks.
>
> --
> tejun
>
--
Sincerely yours,
Mike.
