On Fri, Nov 8, 2019 at 9:53 AM Eric Dumazet <edumazet@xxxxxxxxxx> wrote: > > On Fri, Nov 8, 2019 at 9:39 AM Linus Torvalds > <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > I'd hope that there is some way to mark the cases we know about where > > we just have a flag. I'm not sure what KCSAN uses right now - is it > > just the "volatile" that makes KCSAN ignore it, or are there other > > ways to do it? > > I dunno, Marco will comment on this. > > I personally like WRITE_ONCE() since it adds zero overhead on generated code, > and is the facto accessor we used for many years (before KCSAN was conceived) > BTW, I would love an efficient ADD_ONCE(variable, value) Using WRITE_ONCE(variable, variable + value) is not good, since it can not use the optimized instructions operating directly on memory.
