On Fri, 1 Jun 2007 21:45:15 -0700 (PDT) Christoph Lameter <[EMAIL PROTECTED]> wrote:
> On Fri, 1 Jun 2007, Andrew Morton wrote: > > > They are different instances which happen to have the same length (zero). > > I guess one could use the slab allocators as a type of reservation > ticket generator with zero sized objects. Hmmm.... But is that really a > useful thing to do? > > > But the code will incorrectly decide that they are the same instance. It > > might cause refcounting or accounting errors, for example. I don't know - > > the > > kernel's a big place. > > That would have to occur with objects that are repeatedly allocated and > then linked toghether etc. Linking typicallty requires a listhead so its > typically difficult to do zero length objects. Well I can't immediately think of a scenario in which it's likely to occur, but we're in the position of trying to prove a negative. Poke Bill Irwin - he'll think of something ;) > > I agree the risk is low, but if something _does_ blow up, it will do so > > subtly. > > The cases that we have seen so far are due to array allocations of N > elements where N == 0 leads to the creation of a zero sized object. > The objects of the array are not zero sized it is just that zero of > them are allocated. We lose leak-detection and double-free detection this way, too. Not a big deal. - 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/
