On Mon, Jan 13, 2014 at 06:06:09PM +0100, Oleg Nesterov wrote: > On 01/12, Oleg Nesterov wrote: > > > > The "int check" argument of lock_acquire() and held_lock->check > > are misleading and unneeded. This is only used as a boolean, 2 > > denotes "true", everything else is "false". And this boolean is > > always equal to prove_locking. > > > > The only exception is __lockdep_no_validate__ which should make > > this condition "false" in validate_chain(). > > And I missed mark_irqflags(), > > > @@ -3136,7 +3130,7 @@ static int __lock_acquire(struct lockdep_map *lock, > > unsigned int subclass, > > hlock->holdtime_stamp = lockstat_clock(); > > #endif > > > > - if (check == 2 && !mark_irqflags(curr, hlock)) > > + if (prove_locking && !mark_irqflags(curr, hlock)) > > return 0; > > This change is not right, at least it is not equivalent. > > And I just realized that rcu_lock_acquire() does lock_acquire(check => 1). > Probably we can mark rcu_lock_map's as __lockdep_no_validate__.
Can't, RCU needs its own classes. Otherwise it cannot tell which version of the RCU read lock its holding at just that moment. > Anything else I missed? Nothing springs to mind, but then, I totally missed the RCU thing too. At the very least we can reduce check to a single bit. -- 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/
