On Mon, 1 Jun 2015, Hefty, Sean wrote: > > We want to have a time stamp when the action is complete and the data is > > available to the application or the send action is complete and the CQ > > entry can be reused. > > This is what polling the completion from the CQ tells you, independent of t= > here being a time stamp.
But you may not be polling that frequently. Polling threads may check multiple sources of events and may also currently executing code to handle an event. Also there is the problem of the OS interrupting you. All of these sources of inaccuracy are removed by the timestamp. That was for inbound. For outbound you do not get a timestamp without this feature. Typically reclaim of outbound work requeust is delayed quite a bit and getting a timestamp later does not reflect the actual time the message was sent. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
