On Thu, Sep 17, 2020 at 09:58:02AM -0700, Eric Biggers wrote: > > smp_load_acquire() is obviously correct, whereas READ_ONCE() is an optimization > that is difficult to tell whether it's correct or not. For trivial data > structures it's "easy" to tell. But whenever there is a->b where b is an > internal implementation detail of another kernel subsystem, the use of which > could involve accesses to global or static data (for example, spin_lock() > accessing lockdep stuff), a control dependency can slip in. If we're going to follow this line of reasoning, surely you should be converting the RCU derference first and foremost, no? Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
