On Wed, Oct 28, 2015 at 06:33:56AM +0900, Linus Torvalds wrote: > On Wed, Oct 28, 2015 at 4:53 AM, Davidlohr Bueso <[email protected]> wrote: > > > > Note that this might affect callers that could/would rely on the > > atomicity semantics, but there are no guarantees of that for > > smp_store_mb() mentioned anywhere, plus most archs use this anyway. > > Thus we continue to be consistent with the memory-barriers.txt file, > > and more importantly, maintain the semantics of the smp_ nature. >
> So with this patch, the whole thing becomes pointless, I feel. (Ok, so > it may have been pointless before too, but at least before this patch > it generated special code, now it doesn't). So why carry it along at > all? So I suppose this boils down to if: XCHG ends up being cheaper than MOV+FENCE. PeterA, any idea? -- 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/
