[PATCH 0/2] add new notifier function ,take3

[Takenori Nagano]

Hi,

A big thanks to everybody who read and replied to previous version.

changelog take2 -> take3

- Rebased 2.6.25-rc8-mm1
- comment updated
- renamed the notifiner name "tunable_notifier" to "tunable_atomic_notifier"
- fixed typo
- move control files debugfs to /sys/kernel

These patches add new notifier function and implement it to panic_notifier_list.
We used the hardcoded notifier chain so far, but it was not flexible. New
notifier is very flexible, because user can change a list of order by control files.

Example)

# cd /sys/kernel/notifiers/
# ls
panic_notifier_list
# cd panic_notifier_list/
# ls
ipmi_msghandler  ipmi_wdog
# insmod notifier_test.ko
# ls
ipmi_msghandler  ipmi_wdog  notifier_test1  notifier_test2
# cat */priority
200
150
500
1000
Kernel panic - not syncing: Panic by panic_module.
__tunable_atomic_notifier_call_chain enter
notifier_test: notifier_test_panic2() is called.
notifier_test: notifier_test_panic() is called.
msg_handler:panic_event was called.
ipmi_wdog:wdog_panic_handler was called.

.....(reboot)

# cd /sys/kernel/notifiers/panic_notifier_list/
# ls
ipmi_msghandler  ipmi_wdog  notifier_test1  notifier_test2
# cat */priority
200
150
500
1000
# echo 10000 > ipmi_msghandler/priority
# echo 5000 > ipmi_wdog/priority
# echo 3000 > notifier_test1/priority
# echo 1500 > notifier_test2/priority
# cat */priority
10000
5000
3000
1500
Kernel panic - not syncing: Panic by panic_module.
__tunable_atomic_notifier_call_chain enter
msg_handler:panic_event was called.
ipmi_wdog:wdog_panic_handler was called.
notifier_test: notifier_test_panic() is called.
notifier_test: notifier_test_panic2() is called.

--
Takenori Nagano <t-nagano at ah.jp.nec.com>