On Sun, 2 Sep 2007, Andrew Morton wrote: > > What about using a weak function in that case ? It actually gives a > > default implementation in _one_ place and can be changed easily from a > > nop to something more complex later. > Yeah, weak functions are by far the cleanest way of doing this - they're > most elegant. But they do add the overhead of an empty call/return, so > some thought needs to go into the tradeoff.
Hi, the problem I am seeing with __weak functions is that as far as I can see, gcc 4.1.0 optimizes the empty __weak function away with -O2, so it is not later properly overridden by the other non-weak function, as the callsite already doesn't have the corresponding call. (when I stick a printk() into the __weak function, everything works fine - it is not optimized away and non-weak version of the function gets called). I persume this is a bug in gcc (4.1.1 doesn't seem to expose this behavior). I will look at it a little bit more. Thanks, -- Jiri Kosina SUSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
