Re: [PATCHv3 1/2] mm/memblock: extend the limit inferior of bottom-up after parsing hotplug attr
From: Mike Rapoport
Date: Fri Jan 04 2019 - 10:09:48 EST
On Thu, Jan 03, 2019 at 10:47:06AM -0800, Tejun Heo wrote:
> 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  at the first place :)