[RFC][PATCH 0/3] Embed vmcoreinfo into kernel file

Ken'ichi Ohmichi oomichi at mxs.nes.nec.co.jp
Mon Aug 13 03:32:12 EDT 2007

Hi all,

# I resend this mail, because former mail had a suspicious header.

I updated Dan Aloni's patches for adding the feature that embeds
vmcoreinfo (information for dump filtering) into a kernel file.
This feature frees the restriction that makedumpfile user should
install a vmlinux file (including the debugging information).
Please test it. Your opinions/comments are welcome.

makedumpfile command is the dump filtering feature for kdump.
It creates a small dumpfile by filtering unnecessary pages
for the analysis. To distinguish unnecessary pages, it needs
a vmlinux file including the debugging information.
Now, the debugging package becomes a huge file, and it is hard
to install it into each system. Then, Dan Aloni created the patch
set to embed only necessary information into a kernel binary file,
and a vmlinux file including the debugging informaion is not

Dan Aloni's patch:

- [1/3] patch for linux-2.6.22.
  * Rename "mkdfinfo" to "vmcoreinfo".
  * Multi memory models (FLATMEM, DISCONTIGMEM, and SPASEMEM) are
  * The elf note typedef for vmcoreinfo is added because the original
    elf note size is limited to 1024.
  * The generation of the elf note is moved to boot time instead of
    crash time.

- [2/3] patch for kexec-tools-testing-20070330.
  * Rename "mkdfinfo" to "vmcoreinfo".

- [3/3] patch for makedumpfile-v1.1.6.

- Run the kernel applied the attached patch as the first kernel.
- Preload the second kernel by the kexec-tools applied the attached patch.
- Panic and switch to the second kernel.
- Get a dumpfile by the makedumpfile applied the attached patch:
  (Ex.) # makedumpfile -cd31 /proc/vmcore dumpfile

- ia64 support.
  Translating the virtual address of "vmcoreinfo_note" to the physical address.
- ppc64 support

Ken'ichi Ohmichi

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