The cpu idle code invokes clockevents_notify() during idle state transitions and the cpu offline code invokes it during the CPU_DYING phase. There seems to be a race-condition between the two, where the clockevents_lock never gets released, ending in a lockup. This can be fixed by synchronizing clockevents_notify() with CPU offline, by wrapping its contents within get/put_online_cpus_atomic(). Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> --- kernel/time/clockevents.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 30b6de0..ca340fd 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -17,6 +17,7 @@ #include <linux/module.h> #include <linux/notifier.h> #include <linux/smp.h> +#include <linux/cpu.h> #include "tick-internal.h" @@ -431,6 +432,7 @@ void clockevents_notify(unsigned long reason, void *arg) unsigned long flags; int cpu; + get_online_cpus_atomic(); raw_spin_lock_irqsave(&clockevents_lock, flags); clockevents_do_notify(reason, arg); @@ -459,6 +461,7 @@ void clockevents_notify(unsigned long reason, void *arg) break; } raw_spin_unlock_irqrestore(&clockevents_lock, flags); + put_online_cpus_atomic(); } EXPORT_SYMBOL_GPL(clockevents_notify); #endif -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
