Hi Andrew,

After merging the akpm tree, today's linux-next build (sparc64
defconfig) failed like this:

kernel/built-in.o: In function `proc_dowatchdog':
(.text+0x6a620): undefined reference to `watchdog_hardlockup_detector_is_enabled'
kernel/built-in.o: In function `proc_dowatchdog':
(.text+0x6a6a8): undefined reference to `watchdog_enable_hardlockup_detector'
kernel/built-in.o: In function `proc_dowatchdog':
(.text+0x6a79c): undefined reference to `watchdog_enable_hardlockup_detector'

Caused by commit 72355eed4bd7 ("kernel/watchdog.c: control hard lockup
detection default").  This build has CONFIG_HAVE_NMI_WATCHDOG=y,
CONFIG_HARDLOCKUP_DETECTOR not set.

I have reverted that commit (and commits
"watchdog-control-hard-lockup-detection-default-fix" and "kvm: ensure
hard lockup detection is disabled by default" that follow it) for today.
-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au