On Fri, Sep 05, 2014 at 10:48:34PM +0200, Thomas Gleixner wrote: > On Fri, 5 Sep 2014, Paul E. McKenney wrote: > > On Fri, Sep 05, 2014 at 01:34:52PM -0700, H. Peter Anvin wrote: > > > On 09/05/2014 01:14 PM, Peter Hurley wrote: > > > > > > > > Here's how I read the two statements. > > > > > > > > First, the commit message: > > > > > > > > "It [this commit] documents that CPUs [supported by the Linux kernel] > > > > _must provide_ atomic one-byte and two-byte naturally aligned loads and stores." > > > > > > > > Second, in the body of the document: > > > > > > > > "The Linux kernel no longer supports pre-EV56 Alpha CPUs, because these > > > > older CPUs _do not provide_ atomic one-byte and two-byte loads and stores." > > > > > > > > > > Does this apply in general or only to SMP configurations? I guess > > > non-SMP configurations would still have problems if interrupted in the > > > wrong place... > > > > And preemption could cause problems, too. So I believe that it needs > > to be universal. > > Well preemption is usually caused by an interrupt, except you have a > combined load and preempt instruction :) Fair point! ;-) Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
