On Sunday 05 September 2010 20:32:18 Kulikov Vasiliy wrote: > From: Vasiliy Kulikov <segooon@xxxxxxxxx> > > rcu_dereference() is macro, so it might use its argument twice. > Argument must not has side effects. > > It was found by compiler warning: > drivers/md/raid1.c: In function ‘read_balance’: > drivers/md/raid1.c:445: warning: operation on ‘new_disk’ may be undefined I think the rcu_dereference macro should really not evaluate its argument twice, and I don't see where it does. As a general rule, we try to write macros in Linux such that they behave like functions and don't have surprising side-effects. Which kernel and gcc version do you see the warning with? Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
