On Fri, Mar 22, 2024 at 05:12:29PM -0700, Linus Torvalds wrote: > On Fri, 22 Mar 2024 at 16:57, Kent Overstreet <kent.overstreet@xxxxxxxxx> wrote: > > > > I wonder about that. The disadvantage of only supporting LKMM atomics is > > that we'll be incompatible with third party code, and we don't want to > > be rolling all of our own data structures forever. > > Honestly, having seen the shit-show that is language standards bodies > and incomplete compiler support, I do not understand why people think > that we wouldn't want to roll our own. > > The C++ memory model may be reliable in another decade. And then a > decade after *that*, we can drop support for the pre-reliable > compilers. > > People who think that compilers do things right just because they are > automated simply don't know what they are talking about. > > It was just a couple of days ago that I was pointed at > > https://github.com/llvm/llvm-project/issues/64188 Besides that there's cross arch support to think about - it's hard to imagine us ever ditching our own atomics. I was thinking about something more incremental - just an optional mode where our atomics were C atomics underneath. It'd probably give the compiler people a much more effective way to test their stuff than anything they have now.
