On Mon, 19 Aug 2024 at 01:46, Mark Rutland <mark.rutland@xxxxxxx> wrote: > > If you cannot disclose that for some reason, just say "on my ARM64 test > machine" or something like that, so that we're not implying that this is > true for all ARM64 implementations. It's the same machine I have - an Ampere Altra. It's a standard Neoverse N1 core, afaik. It might also be a good idea to just point to the ARM documentation, although I don't know how stable those web addresses are: https://developer.arm.com/documentation/102336/0100/Load-Acquire-and-Store-Release-instructions and quoting the relevant part on that page: "Weaker ordering requirements that are imposed by Load-Acquire and Store-Release instructions allow for micro-architectural optimizations, which could reduce some of the performance impacts that are otherwise imposed by an explicit memory barrier. If the ordering requirement is satisfied using either a Load-Acquire or Store-Release, then it would be preferable to use these instructions instead of a DMB" where that last sentence is basically ARM saying that load-acquire is better than load+DMB and should be preferred. Linus
