On 08/04, Peter Zijlstra wrote: > > I just noticed that poll_schedule_timeout() uses set_mb() for clearing > its triggered variable. But I'm not entirely sure I see why..
At least we need to ensure that this "pwq->triggered = 0" can't be reordered after the next ->poll() returns 0. In this case we should sleep unless pollwake() was called and it set "->triggered = 1". So without this mb() we can miss an event. But I can hardly understand the "data written before wake up is always visible after wake up" part... Probably this means that if we didn't actually sleep because pwq->triggered == 1 we need to ensure that the next ->poll(file) should see all changes which were the reason for wakeup. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
