Hello, Aleksa. On Wed, Oct 16, 2019 at 07:32:19PM +1100, Aleksa Sarai wrote: > Maybe I'm misunderstanding Documentation/atomic_t.txt, but it looks to > me like it's explicitly saying that I shouldn't use atomic64_t if I'm > just using it for fetching and assignment. Hah, where is it saying that? The alternative would be seqlock or u64_stats or straight-up locking but idk for this atomic64_t should be fine. > > The non-RMW ops are (typically) regular LOADs and STOREs and are > > canonically implemented using READ_ONCE(), WRITE_ONCE(), > > smp_load_acquire() and smp_store_release() respectively. Therefore, if > > you find yourself only using the Non-RMW operations of atomic_t, you > > do not in fact need atomic_t at all and are doing it wrong. > > As for 64-bit on 32-bit machines -- that is a separate issue, but from > [1] it seems to me like there are more problems that *_ONCE() fixes than > just split reads and writes. Your explanations are too wishy washy. If you wanna fix it, please do it correctly. R/W ONCE isn't the right solution here. Thanks. -- tejun
