Re: [PATCH v2 02/22] ieee1275: claim more memory

[Daniel Kiper]

On Fri, Jul 16, 2021 at 05:59:20AM +0200, Patrick Steinhardt wrote:
> On Thu, Jul 15, 2021 at 11:51:04PM +0200, Daniel Kiper wrote:
> > CC-in a few people who can be interested in this...
> >
> > On Wed, Jun 30, 2021 at 06:40:11PM +1000, Daniel Axtens wrote:
> > > On powerpc-ieee1275, we are running out of memory trying to verify
> > > anything. This is because:
> > >
> > >  - we have to load an entire file into memory to verify it. This is
> > >    extremely difficult to change with appended signatures.
> > >  - We only have 32MB of heap.
> > >  - Distro kernels are now often around 30MB.
> > >
> > > So we want to claim more memory from OpenFirmware for our heap.
> >
> > AFAICT it is common problem in the GRUB right now. Please take a look at
> > [1], [2]. It would be nice to find general solution for all. Of course
> > if possible. So, if somebody could take a look at memory management in
> > the GRUB and propose a solution for the problem that would be perfect.
> > Any volunteers?
> >
> > Daniel
> >
> > [1] https://lists.gnu.org/archive/html/grub-devel/2020-06/msg00009.html
> > [2] https://lists.gnu.org/archive/html/grub-devel/2021-01/msg00031.html
>
> I think that my [1] should solve the issue generically. Instead of
> bumping any of the static limits we have in place, we just drop them
> altogether in favor of dynamically requesting additional EFI regions
> whenever we realize that the currently mapped regions cannot satisfy our
> needs. Like this, we can lower the initially requested regions, but
> scale them to the specific needs if need be.
>
> I had planned to revisit this patch series much earlier, but somehow I
> didn't yet find the time. Any comments on my approach would be welcome
> though, and if we agree that this may be a viable route to go down then
> I'd be happy to further pursue it.

Patrick, thanks a lot! I will take a look at the [1] patchset next week.

Daniel A., Stefan, may I ask you to take a look at the [1] too and tell
us how it will work in your cases?

Daniel

[1] https://lists.gnu.org/archive/html/grub-devel/2020-06/msg00009.html