Srivatsa Vaddagiri wrote: > On Tue, Mar 13, 2007 at 06:41:05PM +0300, Pavel Emelianov wrote: >>> right, but atomic ops have much less impact on most >>> architectures than locks :) >> Right. But atomic_add_unless() is slower as it is >> essentially a loop. See my previous letter in this sub-thread. > > If I am not mistaken, you shouldn't loop in normal cases, which means > it boils down to a atomic_read() + atomic_cmpxch() > >
So does the lock - in a normal case (when it's not heavily contented) it will boil down to atomic_dec_and_test(). Nevertheless, making charge like in this patchset requires two atomic ops with atomic_xxx and only one with spin_lock(). - 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/
