Imre Deak <imre.d...@intel.com> wrote: > Many callers of the wait_event_timeout() and > wait_event_interruptible_timeout() expect that the return value will be > positive if the specified condition becomes true before the timeout > elapses. However, at the moment this isn't guaranteed. If the wake-up > handler is delayed enough, the time remaining until timeout will be > calculated as 0 - and passed back as a return value - even if the > condition became true before the timeout has passed.
Fun. > Fix this by returning at least 1 if the condition becomes true. This > semantic is in line with what wait_for_condition_timeout() does; see > commit bb10ed09 - "sched: fix wait_for_completion_timeout() spurious > failure under heavy load". But now you can't distinguish the timer expiring first, if the thread doing the waiting gets delayed sufficiently long for the event to happen. I'm not sure there's a good answer - except maybe making the timer expiry handler check the condition (which would likely get really yucky really quickly). David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
