* Waiman Long <waiman.long@xxxxxx> wrote: > On 08/14/2013 06:20 AM, Ingo Molnar wrote: > >* Waiman Long<waiman.long@xxxxxx> wrote: > > > >> > >>I would like to share with you a rwlock related system crash that I > >>encountered during my testing with hackbench on an 80-core DL980. The > >>kernel crash because of a "watchdog detected hard lockup on cpu 79". The > >>crashing CPU was running "write_lock_irq(&tasklist_lock)" in > >>forget_original_parent() of the exit code path when I interrupted the > >>hackbench which was spawning thousands of processes. Apparently, the > >>remote CPU was not able to get the lock for a sufficient long time due > >>to the unfairness of the rwlock which I think my version of queue rwlock > >>will be able to alleviate this issue. > >> > >>So far, I was not able to reproduce the crash. I will try to see if I > >>could more consistently reproduce it. > >Was it an actual crash/lockup, or a longish hang followed by a lock > >detector splat followed by the system eventually recovering back to > >working order? > > > >Thanks, > > > > Ingo > > It was an actual crash initiated by the NMI handler. I think the > system was in a halt state after that. Could be a CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE=1 kernel? Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
