Paul E. McKenney wrote: >On Fri, Sep 05, 2014 at 02:50:31PM -0400, Peter Hurley wrote: >>On 09/05/2014 02:09 PM, Paul E. McKenney wrote: >>> This commit documents the fact that it is not safe to use bitfields as >>> shared variables in synchronization algorithms. It also documents that >>> CPUs must provide one-byte and two-byte load and store instructions >> ^ >> atomic > > Here you meant non-atomic? My guess is that you are referring to the > fact that you could emulate a one-byte store on pre-EV56 Alpha CPUs > using the ll and sc atomic-read-modify-write instructions, correct? > >>> in order to be supported by the Linux kernel. (Michael Cree >>> has agreed to the resulting non-support of pre-EV56 Alpha CPUs: >>> https://lkml.org/lkml/2014/9/5/143. [...] >>> + and 64-bit systems, respectively. Note that this means that the >>> + Linux kernel does not support pre-EV56 Alpha CPUs, because these >>> + older CPUs do not provide one-byte and two-byte loads and stores. >> ^ >> non-atomic > > I took this, thank you! Eum, am I totally lost, or aren't both of these supposed to say "atomic" ? Can't imagine requiring a CPU to provide non-atomic loads and stores (i.e. requiring old Alpha behavior?). -Marc -- 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
