Re: [PATCH] x86, acpi memory hotplug, add parameter to disable memory hotplug

Toshi Kani
2014-01-14T15:37:28Z

On Tue, 2014-01-14 at 10:26 -0500, Vivek Goyal wrote:
> On Tue, Jan 14, 2014 at 06:05:15AM -0500, Prarit Bhargava wrote:
>
> [..]
> > >>> As mentioned, self-NAK. I have seen a system that I needed to specify
> > >>> memmap=exactmap & had hotplug memory. I will only keep the acpi_no_memhotplug
> > >>> option in the next version of the patch.
> > >>
> > >>
> > >> Your following first patch is simply and makes sense.
> > >>
> > >> http://marc.info/?l=linux-acpi&m=138922019607796&w=2
> > >>
> > >
> > > In this option, it also requires changing kexec-tools to specify the new
> > > option for kdump. It won't be simpler.
> >
> > It will be simpler for the kernel and those of us who have to debug busted e820
> > maps ;)
> >
> > Unfortunately I may not be able to give you the automatic disable. I did
> > contemplate adding a !is_kdump_kernel() to the ACPI memory hotplug init call,
> > but it seems like that is unacceptable as well.
>
> I think everybody agrees that there has to be a stand alone command line
> option to disable memory hotplug.
>
> Whether to tie it into memmap=exactmap and mem=X is the contentious bit.
> So I would suggest that just post a patch to disable memory hotplut using
> a command line and later more patches can go in if people strongly feel
> the need to tie it into memmap=exactmap.
>
> In the mean time, we will modify /etc/sysconfig/kdump to pass
> acpi_no_memhotplug so that user does not have to worry about passing this
> parameter and kexec-tools will not have to be modified either.

Fine by me. Thanks for modifying /etc/sysconfig/kdump file.
-Toshi