Re: [PATCH v7 0/9] kexec-tools, x86: E820 memmap pass for kdump

[Vivek Goyal <vgoyal@redhat.com>]

Hi Chao,

I was testing latest kexec-tools and noticed that I still see some
memmap entries on command line. I think they are ACPI memory and data
areas.

memmap=32K#8192K memmap=960K#8256K memmap=96K#2062752K memmap=16K#2062948K
memmap=32K#2096108K memmap=16K#2096140K

Is there a reason why ACPI related entries should be passed through
command line and not through bootparams memory map.

Thanks
Vivek

On Tue, Apr 22, 2014 at 10:56:38AM +0800, 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!
> 
> v7->v6:
> dyoung/Simon:
>  - more description for CRASH_MAX_MEMMAP_NR to be 1024
> 
> v6->v5:
> dyoung:
>  - use nr_memmap instead of nr_memmap_p
>  - .end inclusive
> Simon:
>  - more description on some patches
> 
> v5->v4:
> Dave:
>  - separate add_setup_data() to another patch.
> Vivek:
>  - adding comments for setup_data.
>  - store crash memory range info golobally in kexec_info.
> me:
>  -remove dbgprint_mem_range defination, Simon has merged the patch.
> 
> v3->v4:
> Linn: check return value of malloc (use xmalloc).
> me: fix dbgprintf_mem_range.
> 
> v2->v3:
> Linn:
>  - do not free sd (setup_data) buffer.
>  - reuse code in setup_e820 and setup_e820_ext.
> 
> v1->v2:
> Vivek:
>  - Use function instead of macro for dbgprint_mem_range
>  - Do not pass reserved memory range for kdump. It could addressed later
>    separately.
> 
> 
> WANG Chao (9):
>   x86, cleanup: add extra arguments to add_memmap() and delete_memmap()
>   x86, cleanup: add_memmap() only do alignment check on RANGE_RAM
>   x86, cleanup: add other types of memory range for 2nd kernel boot to
>     memmap_p
>   x86, cleanup: use dbgprint_mem_range for memory range debugging
>   x86, cleanup: increase CRASH_MAX_MEMMAP_NR up to 1024
>   x86, cleanup: Store crash memory ranges kexec_info
>   x86, cleanup: kexec memory range .end to be inclusive
>   x86: add --pass-memmap-cmdline option
>   x86: Pass memory range via E820 for kdump
> 
>  kexec/arch/i386/crashdump-x86.c        |  69 +++++++--------
>  kexec/arch/i386/crashdump-x86.h        |   2 +-
>  kexec/arch/i386/include/arch/options.h |   2 +
>  kexec/arch/i386/kexec-x86-common.c     |   3 +-
>  kexec/arch/i386/kexec-x86.c            |   4 +
>  kexec/arch/i386/kexec-x86.h            |   1 +
>  kexec/arch/i386/x86-linux-setup.c      | 149 ++++++++++++++++++++++-----------
>  kexec/arch/i386/x86-linux-setup.h      |   1 +
>  kexec/arch/x86_64/kexec-x86_64.c       |   5 ++
>  kexec/firmware_memmap.c                |   1 -
>  kexec/kexec.h                          |   2 +
>  11 files changed, 147 insertions(+), 92 deletions(-)
> 
> -- 
> 1.9.0

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