Re: [v2 0/5] arm64: allow to reserve memory for normal kexec kernel

From: Pavel Tatashin
Date: Wed Jul 10 2019 - 11:53:15 EST


> The crashkernel reservation for kdump is a must, there are already a lot
> of different problems need to consider, for example the low and high
> memory issues, and a lot of other things. I'm not convinced to enable
> this for kexec reboot.
>
> This really looks to workaround the arm64 issue and move the
> complication to kernel.

I will be working on MMU arm64 kernel relocation solution.

Pasha

>
> > On, the other hand hibernate does something similar already, but there
> > MMU never needs to be disabled, and also by the time machine_kexec()
> > is called, allocator is not available, as we can't fail to do reboot,
> > so page table must be pre-allocated during kernel load time.
> >
> > Note: the above time is relocation time only. Purgatory usually also
> > computes checksum, but that is skipped, because --no-check is used when
> > kernel image is loaded via kexec.
> >
> > Pavel Tatashin (5):
> > kexec: quiet down kexec reboot
> > kexec: add resource for normal kexec region
> > kexec: export common crashkernel/kexeckernel parser
> > kexec: use reserved memory for normal kexec reboot
> > arm64, kexec: reserve kexeckernel region
> >
> > .../admin-guide/kernel-parameters.txt | 7 ++
> > arch/arm64/kernel/setup.c | 5 ++
> > arch/arm64/mm/init.c | 83 ++++++++++++-------
> > include/linux/crash_core.h | 6 ++
> > include/linux/ioport.h | 1 +
> > include/linux/kexec.h | 6 +-
> > kernel/crash_core.c | 27 +++---
> > kernel/kexec_core.c | 50 +++++++----
> > 8 files changed, 127 insertions(+), 58 deletions(-)
> >
> > --
> > 2.22.0
> >
> >
> > _______________________________________________
> > kexec mailing list
> > kexec@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/kexec
>
> Thanks
> Dave