On Wed, Feb 05, 2020 at 02:24:38PM +0200, Octavian Purdila wrote: > I was not aware that not allowing GENERIC_ATOMIC64 was intentional. I It might not have been, but presented with this patch, I feel like it should've been :-) > understand your point that a 64 bit architecture that can't handle 64 > bit atomic operation is broken. (sadly they actually exist, I shall name no names) > One way to deal with this in LKL would be to use GCC atomic builtins > or if that doesn't work expose them as host operations. This would > keep LKL as a meta-arch that can run on multiple physical > architectures. I'll give it a try. What is this LKL you speak of and how does it do the 32bit atomics? One thing to keep in mind is that the C11 atomics (_Atomic) don't trivially map to the LKMM -- although I keep forgetting the exact details, there is a paper on it somewhere. Also, once you're limited to a specific arch the issue also becomes much easier than C11 vs LKMM in general.
