Kent Overstreet wrote: > On Thu, Nov 29, 2012 at 09:54:47PM +0100, Andi Kleen wrote: > > > > The regular atomic_t is limited in ways that you are not. > > > > See my original mail. > > > > > > I don't follow, can you explain? > > > > For most cases the reference count is tied to some object, which are > > naturally limited by memory size or other physical resources. > > > > But in the assymetric CPU case with your ref count no such limiter > > exists. > > It's got exactly the same limit as the old code which used the atomic_t > - we're limited by the number of threads that can be issuing aio > syscalls at a time. > > The assymetry you're talking about _doesn't matter_, individual cpu > counters wrapping does not affect what the counters all sum to when we > go to tear down. > > A coworker at lunch actually pointed out to me that the reason this is > true is just that modular arithmatic is still associative with addition > and subtraction. It's just like jiffies. Everyone understands jiffies arithmetic I hope. -- Jamie -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
