On Thu, Sep 26, 2013 at 04:34:04PM +0100, Linus Torvalds wrote: > On Thu, Sep 26, 2013 at 8:13 AM, Will Deacon <will.deacon@xxxxxxx> wrote: > > > > This patch implements a dummy implementation for asm-generic, falling > > back to the usual cmpxchg64 code. > > I don't like the "let's add dummy operations for everybody who doesn't > care" when it is this specialized. > > I'd much rather just add a single > > #ifndef cmpxchg64_relaxed > # define cmpxchg64_relaxed cmpxchg64 > #endif > > to the LOCKREF code, and then ARM (and others) can define it as they wish. Okey doke. > And *if* anybody else ever realizes that they want this outside of the > lockref code, let's look at doing that then. Right now I don't know of > any users, and I'd be leery of people using this willy-nilly, because > very few people really understand memory ordering. Agreed, and I really doubt there are many cases where the cmpxchg hazarding works out nicely so as to obviate the need for memory barriers. I'll send a revised patch. Cheers, Will -- 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
