Hi, The problem is that the call to might_sleep might sleep and the return value of wait_event_timeout does not account for the time slept in there.
The might_sleep includes a call to __schedule if CONFIG_PREEMPT_VOLUNTARY is defined. A problematic scenario can be like the following: - A driver calls wait_event_timeout with timeout = 10 jiffies, starts sleeping in might_sleep. - An interrupt handler sets the condition true at 5 jiffies and calls wake_up for the waitqueue. - Due to high load the might_sleep wakes up at 100 jiffies. - In the next if the __wait_cond_timeout returns 1 without manipulating __ret. - wait_event_timeout returns 10 where it should have returned 1 to denote that a timeout was reached. Or am I misunderstanding what the return value should be ? -- 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/
