Hi Andi,
On Mon, 23 Jul 2007, Andi Kleen wrote: > On Monday 23 July 2007 18:05:58 Satyam Sharma wrote: > > From: Satyam Sharma <[EMAIL PROTECTED]> > > > > [6/8] i386: bitops: Don't mark memory as clobbered unnecessarily > > > > The goal is to let gcc generate good, beautiful, optimized code. > > > The first goal is correct code. > > The reason for the memory barrier is to prevent other memory references > from being moved over the atomic reference. > > e.g. when a bit is used to communicate with another CPU this might be > dangerous. Yes, but _that_ address (of the bit-string) is protected already -- by the implicit memory barrier due to the LOCK prefix. We shouldn't really be caring about any other memory addresses, so it doesn't affect the correctness of the bitops API at all. [ and at least the __test_and_change_bit() case is definitely okay. ] Satyam - 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/
