diff options
| author | Colin Cross <ccross@android.com> | 2013-01-11 13:51:48 -0800 |
|---|---|---|
| committer | Colin Cross <ccross@android.com> | 2014-03-19 13:09:45 -0700 |
| commit | e43009fd646bb519fe5d5f0988c7e8c952dd658d (patch) | |
| tree | c331f00c2692b4e404abf884b72abe311e15dbfd /lib | |
| parent | de091367ead15b6e95dd1d0743a18f0da5a07ee5 (diff) | |
hardlockup: detect hard lockups without NMIs using secondary cpus
Emulate NMIs on systems where they are not available by using timer
interrupts on other cpus. Each cpu will use its softlockup hrtimer
to check that the next cpu is processing hrtimer interrupts by
verifying that a counter is increasing.
This patch is useful on systems where the hardlockup detector is not
available due to a lack of NMIs, for example most ARM SoCs.
Without this patch any cpu stuck with interrupts disabled can
cause a hardware watchdog reset with no debugging information,
but with this patch the kernel can detect the lockup and panic,
which can result in useful debugging info.
Signed-off-by: Colin Cross <ccross@android.com>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 5e2e2344b24..68837d7cf65 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -635,15 +635,27 @@ config LOCKUP_DETECTOR The overhead should be minimal. A periodic hrtimer runs to generate interrupts and kick the watchdog task every 4 seconds. An NMI is generated every 10 seconds or so to check for hardlockups. + If NMIs are not available on the platform, every 12 seconds the + hrtimer interrupt on one cpu will be used to check for hardlockups + on the next cpu. The frequency of hrtimer and NMI events and the soft and hard lockup thresholds can be controlled through the sysctl watchdog_thresh. -config HARDLOCKUP_DETECTOR +config HARDLOCKUP_DETECTOR_NMI def_bool y depends on LOCKUP_DETECTOR && !HAVE_NMI_WATCHDOG depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI +config HARDLOCKUP_DETECTOR_OTHER_CPU + def_bool y + depends on LOCKUP_DETECTOR && SMP + depends on !HARDLOCKUP_DETECTOR_NMI && !HAVE_NMI_WATCHDOG + +config HARDLOCKUP_DETECTOR + def_bool y + depends on HARDLOCKUP_DETECTOR_NMI || HARDLOCKUP_DETECTOR_OTHER_CPU + config BOOTPARAM_HARDLOCKUP_PANIC bool "Panic (Reboot) On Hard Lockups" depends on HARDLOCKUP_DETECTOR |