[PATCH v1 0/3] generalize panic_print's dump function to be used by other kernel parts

[Feng Tang <feng.tang@linux.alibaba.com>]

When working on kernel stability issues, panic, task-hung and 
software/hardware lockup are frequently met. And to debug them, user
may need lots of system information at that time, like task call stacks,
lock info, memory info etc. 

panic case already has panic_print_sys_info() for this purpose, and has
a 'panic_print' bitmask to control what kinds of information is needed,
which is also helpful to debug other task-hung and lockup cases.

So this patchset extract the function out, and make it usable for other
cases which also need system info for debugging. 

Locally these have been used in our bug chasing for stablility issues
and was helpful.

Please help to review, thanks!

- Feng

Changelog:

  Since RFC:
     * Don't print all cpu backtrace if 'sysctl_hung_task_all_cpu_backtracemay'
       is 'false' (Lance Yang)
     * Change the name of 2 new kernel control knob to have 'mask' inside, and
       add kernel document and code comments for them (Lance Yang)
     * Make the sys_show_info() support printk msg replay and all CPU backtrace. 

Feng Tang (3):
  kernel/panic: generalize panic_print's function to show sys info
  kernel/hung_task: add option to dump system info when hung task
    detected
  kernel/watchdog: add option to dump system info when system is locked
    up

 .../admin-guide/kernel-parameters.txt         | 10 ++++
 include/linux/panic.h                         | 11 +++++
 kernel/hung_task.c                            | 42 ++++++++++++-----
 kernel/panic.c                                | 47 ++++++++++---------
 kernel/watchdog.c                             | 20 ++++++++
 5 files changed, 95 insertions(+), 35 deletions(-)

-- 
2.39.5 (Apple Git-154)