On Thu, Aug 16, 2007 at 01:20:26PM -0700, Christoph Lameter wrote: > On Thu, 16 Aug 2007, Chris Snook wrote: > > > atomic_dec() already has volatile behavior everywhere, so this is semantically > > okay, but this code (and any like it) should be calling cpu_relax() each > > iteration through the loop, unless there's a compelling reason not to. I'll > > allow that for some hardware drivers (possibly this one) such a compelling > > reason may exist, but hardware-independent core subsystems probably have no > > excuse. > > No it does not have any volatile semantics. atomic_dec() can be reordered > at will by the compiler within the current basic unit if you do not add a > barrier. Yep. Or you can use atomic_dec_return() instead of using a barrier. Thanx, Paul - 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/
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