From 55d35d82b7181312d75b8fe67a90a605ffde66b9 Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Fri, 11 Jan 2013 13:51:48 -0800 Subject: 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. Change-Id: Ia5faf50243e19c1755201212e04c8892d929785a Signed-off-by: Colin Cross --- include/linux/nmi.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux/nmi.h') diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 7ec5b86735f3..74385351935d 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -14,8 +14,11 @@ * may be used to reset the timeout - for code which intentionally * disables interrupts for a long time. This call is stateless. */ -#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR) +#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR_NMI) #include +#endif + +#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR) extern void touch_nmi_watchdog(void); #else static inline void touch_nmi_watchdog(void) -- cgit v1.2.3