Bug#584881: Lockups under heavy disk IO; md (RAID) resync/check implicated

[Ian Jackson <ijackson@chiark.greenend.org.uk>]

I wrote:
> ...  I'm going to compile the kernel again without that particular
> warning (and with kgdb support) and see if I can dig out anything
> interesting.

My attempt to compile the kernel with kgdb support failed.  Something
in the Debian kernel packaging thingy complained like this:
  ABI has changed!  Refusing to continue.
  Added symbols:
  kgdb_breakpoint                                  module: vmlinux,
  version: 0x01e1a8de, export: EXPORT_SYMBOL_GPL
...
  Changed symbols:
  __audit_inode_child                              module: vmlinux, version: 0xead6af60 -> 0xe3835d2d, export: EXPORT_SYMBOL_GPL
  __fatal_signal_pending                           module: vmlinux, version: 0xb5428735 -> 0xee8d0603, export: EXPORT_SYMBOL
  [lots more]

I've run out of time to do more on this now.

Ian.