Il 08/08/2012 15:32, Peter Maydell ha scritto: >> > 1. GCC atomics look ugly, :) do not provide rmb/wmb, and in some >> > versions of GCC mb is known to be (wrongly) a no-op. >> > >> > 2. glib atomics do not provide mb/rmb/wmb either, and >> > g_atomic_int_get/g_atomic_int_set are inefficient: they add barriers >> > everywhere, while it is clearer if you put barriers manually, and you >> > often do not need barriers in the get side. glib atomics also do not >> > provide xchg. > These are arguments in favour of "don't try to use atomic ops" -- > if serious large projects like GCC and glib can't produce working > efficient implementations for all target architectures, what chance > do we have? Well, maybe... but the flaws in both GCC and glib are small in size (even though large in importance, at least for us) and we can work around them easily. mb/rmb/wmb is essentially the small set of atomic operations that we're already using. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
