Re: [PATCH v6 0/9] kexec-tools, x86: E820 memmap pass for kdump

Linn Crosetto
2014-04-18T19:57:37Z

On Thu, Apr 17, 2014 at 02:24:20PM +0800, WANG Chao wrote:
> On 04/14/14 at 10:55pm, WANG Chao wrote:
> > Hi, All
> >
> > This patchset enables passing memory map via E820 map on x86 platform instead
> > of memmap=exactmap. It's a better design and will solve the following problem
> > so far:
> >
> > - kernel cmdline is limited resource and large machines tend to have many
> > memory ranges that may excceed kernel cmdline limit size.
> > - kASLR doesn't work with memmap=exactmap, because kASLR happens early than
> > user defined memmap=exactmap takes effect.
> >
> > Unfortunately, saved_max_pfn still got its user out there (calgry pci, it looks
> > like the only one). So for backward compatibility, I'm introducing a new option
> > --pass-memmap-cmdline to force kexec-tools to pass memmap=exactmap, the old way.
> >
> > This patchset contains massive updates from the previous one. I take some
> > suggestions from reviewers. I try to split the changes into smaller pieces and
> > keep the whole change as minimal as I can so it wouldn't be too harsh to review
> > the patch.
> >
> > Any comment is appreciate!
>
> Hi, Linn
>
> Thanks for testing the patch in the past. Do you have chance to test
> this update?
>
> This updated patchset changed too much and I want things to work as it's
> used to be on your prototype machine with large number of memory ranges.
>
> Thanks in advance!
> WANG Chao

Tested the series on a system with 200+ entries in the map; both kexec and kdump
(with and without --pass-memmap-cmdline). Thanks for the patches.

Tested-by: Linn Crosetto <linn@hp.com>