On 12/07, Srivatsa S. Bhat wrote: > > CPU 0 CPU 1 > ------ ------ > > 1. Acquire lock A Increment CPU1's > atomic counter > > > > 2. Increment CPU0's Try to acquire lock A > atomic counter > > > Now consider what happens if a hotplug writer (cpu_down) begins,
Exactly. So the fake lockdep_map should be per-cpu as well. lglock doesn't need this because lg_local_lock() is not recursive and lockdep can catch the bug like this. So it can look as single lock for lockdep. IOW. If you use the global lockdep_map and want lockdep to notice this deadlock you need rwlock_acquire_read(map, 0, 0, IP). But then lockdep will complain if the task does "read lock" under "read lock". Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
