I'm looking at how MADs are timed out in drivers/infiniband/core/mad.c and I think that the timeouts are just implemented incorrectly. An ib_mad_send_wr_private's timeout value is always initialized like this: mad_send_wr->timeout = msecs_to_jiffies(send_buf->timeout_ms); This converts a timeout value in milliseconds to a relative value in jiffies (e.g. if timeout_ms is 500 and HZ is 100, then msec_to_jiffies returns 5). However there are a number of places in mad.c that use this as though it's an absolute jiffies value. For example, timeout_sends() compares the value to the current jiffies counter: https://code.woboq.org/linux/linux/drivers/infiniband/core/mad.c.html#2853 This doesn't make any sense. In principle it should be fixed by instead initializing timeout as follows: mad_send_wr->timeout = jiffies + msecs_to_jiffies(send_buf->timeout_ms); but there are also a number of places that check if timeout > 0 to see if it's active and that needs to be fixed, possibly with a separate active flag. Am I missing something, or is this just broken?
