On Thu, Jun 07, 2018 at 10:18:27AM +0200, Daniel Lezcano wrote: > So IIUC, neither atomic or WRITE|READ_ONCE are necessary in this code > because of the wake_up_process() barrier is enough, right ?
I didn't look hard enough; if there ever is a time where the loads and stores happen concurrently, you need READ/WRITE_ONCE(). If there is no concurrency on the variables, you don't need anything. Neither atomic_read/set() nor REAd/WRITE_ONCE() will help with ordering, which is what the wake_up_process() would provide here, different things entirely.
