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

Vivek Goyal
2014-01-14T14:38:01Z

On Tue, Jan 14, 2014 at 06:05:15AM -0500, Prarit Bhargava wrote:
>
>
> On 01/13/2014 08:41 PM, Toshi Kani wrote:
> > On Tue, 2014-01-14 at 10:11 +0900, Yasuaki Ishimatsu wrote:
> > :
> >>>> I think we need a knob manually enable mem-hotplug when specify memmap. But
> >>>> it is another story.
> >>>>
> >>>> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> >>>
> >>> 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.

Yep, I don't think hotplug feature should be tied to it being a kdump
kernel.

Thanks
Vivek